Walker and Civil Aviation Safety Authority
[2025] ARTA 27
•9 January 2025
Decision and Reasons for Decision
Walker and Civil Aviation Safety Authority [2025] ARTA 27 (9 January 2025)
Applicant/s: Matthew Walker
Respondent: Civil Aviation Safety Authority
Tribunal Number: 2023/4282
Tribunal: Senior Member T Tavoularis
Place: Brisbane
Date: 9 January 2025
Decision: The Tribunal affirms the decision under review.
.................[SGD]............................
Senior Member T Tavoularis
Catchwords
CIVIL AVIATION – Class 2 Medical Certificate – medical standards - examination of medical evidence – manic episode - whether Applicant meets necessary medical standard – assessment of extend to which Applicant does not meet necessary standard – whether conditions could be imposed on a medical certificate - decision of the respondent affirmed
Legislation
Administrative Review Tribunal Act 2024 (Cth)
Civil Aviation Act 1988 (Cth)
Cases
Re Mulholland and Civil Aviation Safety Authority [2007] AATA 1952 Collins and Civil Aviation Safety Authority [2017] AATA 2564
Secondary Materials
Civil Aviation Safety Regulations 1998 (Cth)
Diagnostic and Statistical Manual of Mental Disorders (Version 5)
International Civil Aviation Organisation (International Standards and Recommended Practice – 12th edition)
Statement of Reasons
INTRODUCTION
On 5 June 2023, a delegate of the Civil Aviation Safety Authority (‘the Respondent’ or ‘CASA’) refused to issue Mr Matthew Walker (‘the Applicant’) with a Class 2 Medical
Certificate.1 Sub-regulation 61.410 of the Civil Aviation Safety Regulations (‘CASR’) provides that a holder of a private pilot licence is only authorised to exercise the privileges of that license provided they contemporaneously hold a Class 1 or Class 2 Medical Certificate. Put simply, the Applicant will not be able to fly an aircraft without either of these Medical Certificates.
The basis of the refusal appearing in the Decision Under Review derives from the Applicant’s medical history of having experienced a single manic episode, with psychotic features in October 2018. The Applicant now seeks review of that refusal. The instant hearing proceeded before me 11, 12, 25 and 29 November 2024. The hearing essentially devolved into a contest about the medical evidence. The hearing received written and oral evidence from:
·the Applicant;
·Dr Stephen McConnell, Consultant Psychiatrist;
·Dr Robert Liddell, specialist in Aviation Medicine;
·Dr Greg Apel, Psychiatrist;
·Dr Elizabeth Ryan, Senior Medical Officer – CASA Aviation Medicine Section;
·Dr Michael Atherton, Psychiatrist and addiction specialist.
The totality of the material was, with the agreement of the parties, reduced to an agreed Exhibit List, a true and correct copy of which is attached to these Reasons and marked ‘ANNEXURE A’.
THE ISSUES FOR DETERMINATION
The Tribunal’s review of the Decision Under Review is predicated on the safety of air navigation being the most important consideration. To determine the challenge to the Decision Under Review, the Tribunal is required to address the following issues:
(a)does the Applicant meet the necessary medical standard for the issue of a Class 2 Medical Certificate?
1 I will refer to this decision as the Decision Under Review.
(b)if he does not, it is then necessary for the Tribunal to determine whether the extent to which he fails to do so is likely to endanger the safety of air navigation; and
(c)depending on the Tribunal’s findings about the immediately preceding sub- paragraph (b), whether there are any conditions that could be imposed on a medical certificate ameliorating the threat posed to the safety of air navigation.
THE APPLICANT
Relevant aviation experience
The Applicant is 31 years of age. He completed his professional pilot training in New Zealand in 2014 that saw him (a) receive a Diploma in Aviation; (b) have a Commercial Pilot’s Licence with Multi-Engine Instrument Rating issued to him; and (c) have a C- Category flight instructor rating issued to him. He worked as a commercial pilot in New Zealand for 12 months and then moved to Australia in 2015.
After arriving here, the Applicant became involved in parachuting and completed the requirements for a ‘Jump Pilot Authorisation’ while working at the Torquay (parachute) drop zone during the period 2015-2018. During this period, he piloted Cessna 182 and 206 piston – powered aircraft and Cessna 208 turbine – powered aircraft on parachute dropping operations. His qualifications obtained in New Zealand enabled him to perform his aviation roles in Australia pursuant to the Trans-Tasman Mutual Recognition Treaty.2
His work activities in parachuting saw him undertake certain skydiving training resulting in the Australian Parachuting Federation (‘APF’) issuing certain licenses and ratings to him. The Applicant travelled to the United States to enhance his experience in the field of parachuting. This culminated in the Applicant returning to Australia and successfully completing qualifications as a tandem parachuting instructor. He remained at the Torquay parachuting drop zone during the period 2017 – 2018 which saw him working as a pilot of aircraft dropping parachutists as well as taking customers on tandem skydives.
The basic reason behind the Applicant’s current challenge to the Decision Under Review is best described in his Statement of Facts, Issues and Contentions (‘SFIC’):
2 A1, p. 2, [2].
Piloting drop aircraft is considered a private operation and requires a Private Pilot License or higher, and a Class 2 Flight Medical or higher. APF rules require Tandem Masters (i.e. tandem instructors) to hold Medical Certificate – Class 2 or higher; or a Basic Class 2 medical certificate. The latter certificate is issued by CASA based upon certification by an appropriate medical practitioner that the applicant complied with the Austroads commercial driving standards.
Medical symptoms
According to the Applicant’s SFIC, parachuting seems to be somewhat weather-dependant and parachuting operations seem to quieten during the winter months. This saw the Applicant travel to Edmonton in Alberta, Canada where he accepted a position at a skydiving centre during the northern hemisphere summer of 2018. His duties in Canada were essentially the same as at Torquay, Australia. That is, he worked as a pilot of aircraft that dropped parachutists and as a tandem parachuting instructor.
While working in Canada, the Applicant noted that ‘… virtually all the staff there (who resided on site) were immersed in a recreational drug culture’.3 In his SFIC, the Applicant claims to have not previously used illicit substances until he commenced working in Canada but that he ‘… succumbed to the temptation and by the end of the summer [i.e. the northern hemisphere summer of 2018] was heavily immersed – mainly using cannabis (which was then legal in Alberta) daily’.4
When the Canadian summer skydiving season ended, the Applicant travelled to Mexico with his parachuting colleagues prior to his intended return to Australia. He concedes in his SFIC that while in Mexico, his cannabis and other drug use escalated. His SFIC goes on to say:
‘… By early October 2018, Applicant was exhibiting unusual behaviour. On or about the 4th or 5th of October 2018, Applicant's erratic behaviour resulted in him being arrested by local police and held for a period of about 24 hours without access to food or water, until police released him into the care of his friends. Between his release and 9 October 2018, Applicant and his friends made their way to Los Angeles, CA, USA to catch a flight back to Melbourne, Australia. Applicant's last drug use was about October 2nd or 3rd - immediately prior to his arrest in Mexico’.5
3 A1, p. 3, [5].
4 A1, p. 3, [5].
5 A1, p. 3, [6]
His friends alerted the Applicant’s mother (then in New Zealand) who travelled to Melbourne to meet him. The Applicant’s mother contacted a psychologist who arranged for the Applicant to be taken to the Geelong Hospital. There followed an involuntary admission to the Barwon Health Swanston Centre on 16 October 2018 where he remained as in in-patient for 20 days. Following his discharge on 5 November 2018, the Applicant remained subject to a Community Treatment Order.
While an in-patient at the Barwon Health Swanston Centre, the supervising psychiatrist, Dr Allison Taylor, issued notifications to both VicRoads6 and CASA that saw both his driving and flying privileges suspended. Since this time, the Applicant has sought to re-establish his credentials to resume his activities as a remote drop-zone parachute pilot and a tandem parachuting instructor. This application represents the culminating point of that endeavour.
THE DECISON UNDER REVIEW
The Decision Under Review was made on 5 June 2023 and relevantly appears in the material.7 The Respondent based its findings on three components on the evidence. First, it had regard to the report of the consultant psychiatrist, Dr Brooke Burchgaurt dated 12 April 2023. Dr Burchgaurt diagnosed the Applicant having experienced a severe manic episode with psychotic features resulting from protracted substance use. Second, the Respondent had regard to the report of the consultant psychiatrist, Dr Stephen McConnell, who opined the Applicant ‘…had a one off ‘first’ manic episode with psychotic features during 2018. This occurred in the context of recreational drug use during 2018’.8
Third, the Respondent took into account certain correspondence from the Applicant in which he spoke of (1) having completely recovered from the single manic episode; (2) having a firm commitment towards maintaining an abstinence from using illicit substances; and (3) there being a low risk of him experiencing any recurrence of a manic episode. In this correspondence, the Applicant indicated a willingness to accept the imposition of conditions on the Class 2 Medical Certificate he was seeking. Those conditions involved ongoing psychiatric and substance surveillance.
6 Denoting the authority regulating the issuing of Diver Licenses in Victoria.
7 R1, pp. 8 – 12.
8 R1, p. 258.
In its Decision Under Review, the Respondent’s Senior Medical Officer refused the Class 2 Medical Certificate on the basis of (1) the Applicant’s failure to meet the Class 2 medical standard; and (2) that no conditions which could be imposed on the grant of the certificate would negate the risk which the Applicant’s condition presents to the safety of air navigation.
THE LEGAL REQUIREMENTS ATTENDING THE ISSUE OF A CURRENT MEDICAL CERTIFICATE
The Respondent’s SFIC contains a helpful summary of requirements and thresholds the Applicant must meet for the grant of the certificate denied to him by the Respondent.9 In short compass, those elements are these:
·the privileges of a private pilot license can only be exercised if the holder of that license contemporaneously holds a Class 1 or Class 2 Medical Certificate (Subregulation 61.410 of the CASR);
·the Respondent can issue a medical certificate to a person ‘subject to any condition that CASA is satisfied is necessary in the interests of the safety of air navigation’ (Regulation 11.056 of the CASR);
·the issue of a medical certificate will not be made if it is found that the person either (1) fails to meet the ‘relevant medical standard’; or (2) to the extent to which the person fails to meet that standard is ‘likely to endanger the safety of air navigation’;
·the standard applicable to the issue of a Class 2 Medical Certificate appears in Table 67.155 of the CASR in these terms:
‘Abnormalities, disabilities and functional capacity
2.1 Has no safety-relevant condition of any of the following kinds that produces any degree of functional incapacity or a risk of incapacitation:
(a)an abnormality;
(b)a disability or disease (active or latent);
(c)an injury;
(d)a sequela of an accident or a surgical operation.
Mental fitness
9 See R2, p. 4-6, [15]-[23].
2.4 Has no established medical history or clinical diagnosis of any of the following conditions, to an extent that is safety relevant:
(a)psychosis;
(b)significant personality disorder;
(c)significant mental abnormality or neurosis.
2.5 Does not engage in any problematic use of substances (within the meaning given by section 1.1 of Annex 1, Personnel Licensing, to the Chicago Convention)
2.6If there is any personal history of problematic use of a substance (within the
meaning given by section 1.1 of Annex 1, Personnel Licensing, in the Chicago Convention):
(a) the person’s abstinence from problematic use of the substance is certified by an appropriate specialist medical practitioner; and
(b) the person is not suffering from any safety relevant sequelae resulting from the person’s use of the substance; and
(c) the person provides evidence that the person is undertaking, or has successfully completed, an appropriate course of therapy
Note: In Annex 1, Personnel Licensing, to the Chicago Convention, Problematic use of substances; is defined as follows:
'The use of one or more psychoactive substances by aviation personnel in a way that:
a) constitutes a direct hazard to the user or endangers the lives, health or welfare of others; and/or
b) causes or worsens an occupational, social, mental or physical problem or disorder.
'Psychoactive substances' is there defined as 'Alcohol, opioids, cannabinoids, sedatives and hypnotics, cocaine, other psychostimulants, hallucinogens, and volatile solvents, whereas coffee and tobacco are excluded.'.
·in exercising its discretion to grant the certificate sought by the Applicant, the Respondent’s primary consideration is the safety of air navigation (Section 9A of the Civil Aviation Act 1988 (Cth) (‘CA Act’));
·the Applicant’s condition is a ‘medically significant condition’ because of the definition of this term in regulation 67.010 of the CASR:
“medically significant condition" includes:
(a)any of the following (no matter how minor):
(i)any illness or injury;
(ii)any bodily infirmity, defect or incapacity;
(iii)any mental infirmity, defect or incapacity;
(iv) any sequela of an illness, injury, infirmity, defect or incapacity mentioned in subparagraph (i), (ii) or (iii); and
(b)any abnormal psychological state; and
(c)drug addiction and drug dependence; and
(d) for a woman--pregnancy and the physiological and psychological consequences of pregnancy or of termination of pregnancy;
·Regulation 67.015 of the CASR provides that ‘… a medically significant condition is safety-relevant [for the purposes of the standard applicable to the issue of a Class 2 Medical Certificate] if it reduces, or is likely to reduce the ability of someone who has it, to exercise a privilege conferred or to be conferred, or perform a duty imposed or to be imposed, by a license that he or she holds or has applied for’.
The assessment of the risk around the extent to which a medically significant condition reduces, or is likely to reduce, the Applicant’s ability to safely exercise the privilege(s) afforded by a private pilot license is generic to these types of aeromedical decisions. The calculation of such risk is addressed by Dr Elizabeth Ryan in these terms:
‘Calculation of risk in aeromedical decisions
15. In an aeromedical context, risk is referred to as ‘absolute’ risk which is the risk of developing an incapacitating condition over a period of time, rather than ‘relative’ risk, which is used to compare the risk in two different groups of people.
16. The risk of incapacitation is often expressed as annual percentage. For example, a pilot incapacitation risk of ‘1% per annum’ means that if there are 100 pilots with an identical condition, one of them would be predicted to become incapacitated at some time during the next 12 months (and 99 would not).
Use of numerical criteria in aeromedical decision making
17. Numerical criteria are used as a means of facilitating fast, efficient and consistent decision-making in cases where the question is whether the condition is likely to reduce the ability of the applicant to exercise a privilege or perform a relevant duty – in other words, such criteria enable the making of a decision where the criteria for the relevant medical standard involved determining whether the condition in question is “safety-relevant”.
18. Once it is determined that an applicant for a Medical Certificate does not meet the relevant medical standard, a decision must be made as to the extent to which he or she does not meet that standard and whether that is likely to endanger the safety of air navigation. This decision is guided by the numerical criteria (as providing as boundary). The normally acceptable risks for a commercial operation,
requiring a Class 1 Medical Certificate, are in the range of 1-2% (annual risk of an event that can cause incapacitation). The normally acceptable risks for a private operation, requiring a Class 2 Medical Certificate, are in the range of 2- 5%. Usually, a pilot at the lower range can expect to get unrestricted certification and those above the lower limit can expect to have some conditions placed on the Medical Certificate’.10
[The bold in [18] is my emphasis]
This absolutist (as opposed to a relativist) approach to risk assessment in aeromedical decisions has its endorsement in at least two decisions of this Tribunal. First, in Re Mulholland and Civil Aviation Safety Authority [2007] AATA 1952, this Tribunal said:
‘65. Whether Mr Mulholland has a high risk or a low risk of losing consciousness while flying an aircraft is simply irrelevant. The fact is that he has a risk of incapacitation which is significantly different to the remainder of the aviator population who do not suffer from syncope or any other safety relevant medical condition…
66. Whatever the risk may be of Mr Mulholland suffering a syncopal attack whilst flying, it is not to the point that it can be shown statistically that the risk is small…What is important is whether Mr Mulholland meets the requirements for the issue of a Class 1 or Class 2 medical certificate. If he does not, the only question remaining is whether CASA should issue to Mr Mulholland medical certificates with conditions in accordance with regulation 67.195 of the CASR…’.11
Second, Dr Ryan’s abovementioned ranges for acceptable risks for commercial operation requiring a Class 1 Medical Certificate and for private operation requiring a Class 2 Medical Certificate had their endorsement in this Tribunal in Collins and Civil Aviation Safety Authority [2017] AATA 2564:
‘There is a generally accepted guideline in international aviation that a 1% annualized risk of incapacitation is the acceptable level of risk. This rule is set out and explained in the International Civil Aviation Organisation (ICAO) Manual of Civil Aviation Medicine. ICAO is a United Nations agency established in 1944 which governs the Convention on International Civil Aviation, the Chicago Convention, of which Australia is a Member State.
…
…the Tribunal sees no reason why it should abandon the 1% rule, or 2% rule as adopted by CASA as a guideline in cases concerning Class 2 Medical Certificates. In any event, as was made clear in Mulholland, there is no 1% rule. What is necessary is that there is a real, not remote risk. However, the internationally
10 R5, pp. 7-8, [15]-[8]
11 At [65] and [66],
accepted guideline can play a useful, if not critical, exercise in assessing risk and in ensuring consistency in decision making concerning air navigation safety’.12
[My emphasis]
THE MEDICAL EVIDENCE
Upon his return to Australia after the episode in Mexico, the Applicant was admitted to the
Gelong Hospital on 16 October 2018. The record of that hospital indicates:
·a provisional diagnosis of substance induced psychosis13;
·a working diagnosis of a first episode substance induced psychosis14;
Shortly after his release from the Geelong Hospital, the Applicant sought an independent second psychiatric opinion. The relevant report is dated 16 December 2018 and is authored by Dr David Fenn, Consultant Psychiatrist. Dr Fenn reviewed the clinical notes from the Applicant’s time at the Gelong Hospital and noted ‘The medical notes record a diagnosis of mania with psychotic features and note that this episode of illness meets the criteria for a diagnosis of bipolar affective disorder’.15
Dr Stephen McConnell, Consultant Psychiatrist, has provided four written reports. The first is dated 7 March 2019. In this report, Dr McConnell notes that upon admission to the Geelong Hospital, the Applicant had been diagnosed with a ‘first manic episode with psychotic features’.16 Following an in-person consultation with the Applicant on 13 December 2018 and then via teleconference on 7 March 2019, Dr McConnell opined that: ‘On the 13/12/18 [the Applicant] did not present with any ongoing reported symptoms or features of any form of mental illness including no evidence of ongoing mania or psychosis’.17
Dr McConnell said ‘My decision was that there was no psychiatric indication to force [the Applicant] to take psychotropic medication but I kept [the Applicant] on a Community
12 R2, pp 7-8, [26] and [27].
13 R1, p.89.
14 R1, p.116.
15 R1, p. 434.
16 R1, p. 46.
17 R1, p. 47.
Treatment Order to stipulate that he had to return to Jigsaw [a local mental health service] for further monitoring of his progress’.18 Dr McConnell thought that by March 2019, the Applicant had ‘…made a full recovery from his manic episode’.19 Noting the Applicant’s resistance towards taking psychotropic medication, Dr McConnell thought the Applicant’s position on taking medication ‘… should be respected i.e. there was no indication to override [the Applicant’s] wish to maintain his full recovery via non-medication means’.20
The second of Dr McConnell’s reports is dated 30 April 2019. It is, in fact, a report written in conjunction with the clinical psychologist, Mr John Lukies. In this report, its authors say the Applicant ‘…presented with some residual symptoms of mental illness on 13/12/18’.21 The report further notes that following subsequent reviews, the Applicant ‘…was no longer presenting with any obvious symptoms of mental illness…’22 The report concludes with: ‘… on the evidence available to us, we can see no reason why any skydiving license that would otherwise be granted to [the Applicant] should any longer be withheld from him on the grounds of mental impairment’.23
Dr McConnell’s third report is dated 16 November 2022. In this report, Dr McConnell opines thus:
‘IMPRESSION: [The Applicant] had a one off ‘first’ manic episode with psychotic features during 2018. This occurred in the context of recreational drug use during 2018.
…
Whilst I cannot provide a definitive guarantee that [the Applicant] could never experience a manic episode in the future, based on my current assessment, I currently assess his risk of having another episode as being at low risk or probability.
…
In theory, one differential diagnostic possibility is that during 2018, [the Applicant’s] drug use interacted with an underlying mental health vulnerability suggestive of Bipolar Disorder. Whilst I cannot categorically exclude this possibility, based on all information available and as already summarised, a diagnosis of Bipolar Disorder is less likely and was not a correct diagnosis previously and can’t be made currently as per reasons already stated i.e given [the Applicant] had a one off episode, in the
18 R1, p. 47.
19 R1. p. 47.
20 R1. p. 47.
21 R1, p. 147.
22 R1, p. 147.
23 R1, p. 147.
context of drug use at the time, with no ongoing drug use and he has been completely well with his mental health since, with no need for ongoing psychiatric medication’.24
The fourth and final report of Dr McConnell was made on 24 April 2024. This report is couched in terms of a ‘supplementary report’ and is responsive to a specific comment in the report of Dr Elizabeth Ryan dated 12 March 2024 wherein Dr Ryan said the following:
‘…Dr Buchgard [sic] states in his [sic] report that he [sic] feels the diagnosis is single manic episode, severe, with psychotic features. He [sic] clearly states that a substance induced mood disorder is as a less convincing differential diagnosis due to how long the manic symptoms persisted after the psychoactive substance was ceased. This fact is not addressed in Dr Liddell’s report. Dr McConnell also states the diagnosis is first manic episode, as does Dr Atherton. None of the three specialists agree that this was a drug-induced episode, but rather a first manic episode, therefore consistent with the diagnosis of bipolar 1 disorder’.25
In his supplementary report of 24 April 2024, Dr McConnell is keen to dispel Dr Ryan’s suggestion of him concurring with a diagnosis of bipolar 1 disorder:
‘Use of the terminology of ‘first episode’ is not meant by its use to have predictive value about a person’s prognosis such as predicting at that time if a person has an underlying enduring mental illness such as Bipolar Disorder. As per my report, I did not assess that [the Applicant] had a definite diagnosis of Bipolar Disorder given he had a one off episode complicated by drug use leading up to his one off ‘first episode’’.26
Dr Greg Apel: is a psychiatrist who interviewed the Applicant on 2 July 2024. Dr Apel subsequently produced a report dated 26 July 2024 which relevantly appears in the material.27 Dr Apel initially notes the Applicant ‘… suffered an episode of severe psychiatric illness in 2018 and has subsequently been well-functioning’.28 Following a recounting of the Applicant’s history culminating in him being admitted to the Geelong Hospital upon return to Australia, Dr Apel notes the Applicant ‘… related no recurrence or psychiatric symptoms since this time. These include detailed enquiry of modest levels of elevation or depression’.29
24 R1, p. 258.
25 R5, pp. 12 – 13, [32].
26 A6.
27 A8.
28 A8, p. 1.
29 A8, p. 5.
At interview, Dr Apel observed the Applicant ‘… presented as neither significantly anxious or depressed and no evidence of psychosis or suicidality’. 30 Dr Apel found ‘…no history of trauma, psychological illness or episodes of functional impairment over his [the Applicant’s] childhood, adolescence and young adult life.’31 Dr Apel accepted that upon return to Australia from Mexico in October 2018, the Applicant ‘… was obviously grossly unwell…’32 but following discharge from the Geelong Hospital in November 2018, the Applicant ‘… has remained well…’33 since discharge.
Dr Apel was equivocal and otherwise unclear about allocating a specific diagnostic finding to the Applicant’s symptoms following his admission to the Geelong Hospital in October 2018. He opined thus:
‘To me, diagnostic issues are not clear. His illness can best be characterised from the notes of a manic episode with psychotic features. This was initially diagnosed as Bipolar Disorder with a single manic episode under DSM – V but the individual characterisations were dropped in DSM -V, although of course this effects treatment logic. However, this diagnosis of Bipolar Illness is on the proviso that it is only applicable if the presentation is not better explained by another psychotic disorder’.34
Dr Apel regarded a drug induced psychosis as a plausible differential diagnosis. He regards these symptoms leading to a drug induced psychosis to be ‘reversable’35 but that they ‘…can be triggered by a number of agents and tends to be dose related and will be present as long as the substances are in the system’.36 Dr Apel inclines toward the Applicant experiencing a drug-induced psychosis in Mexico in September/October 2018. He rationalises that opinion in these terms:
‘…[drug-induced] episodes of illness are more discrete and will tend to be brief for the drug as methamphetamine and cocaine but considerably longer for a fat-soluble drugs such as cannabis’. One point towards this was his account to me of suffering visual hallucinations whilst incarcerated in Mexico. However, there may have been dehydration and sleep deprivation to contribute to this. Nevertheless, this would be uncommon in a Bipolar illness and far more common in a drug-induced state’.37
30 A8, p. 15.
31 A8, p. 16.
32 A8, p. 16.
33 A8, p. 16.
34 A8, p. 18.
35 A8, p. 18.
36 A8, p. 18.
37 A8, p. 18.
In terms of a diagnostic finding, Dr Apel reaches this conclusion:
‘As such at the point that a diagnosis is simply not clear, based on a single data point of one episode of illness. The diagnosis of Bipolarity carries the assumption this is a lifelong illness with recurrent episodes and quite significant morbidity. The concept of a drug-induced psychosis and episodes related to his substance use and would not arise without further substance use. As such from myself, the point here is not to try and squeeze an atypical case into any particular diagnostic category but to rather accept the situation is simply not clear’.38
[My Emphasis]
According to Dr Apel, if a person does not neatly fit into a diagnostic category, ‘…we are drawn to the second level of evidence and logic about this matter which is the general clinical syndrome of presentation’.39 This is addressed via a clinician’s expert opinion and experience. On this basis, Dr Apel opines that ‘…in bipolar illness the syndrome would tend to involve depressive episodes, subsyndromal, in early or teenage years. The declaration of manic episodes often becomes explanatory as to why there have been episodes of poorer function earlier on.40
By way of contrast, Dr Apel says: ‘… a drug-induced psychosis… tends to be more discrete, and recovery tends to be faster and lasting. As such overall the clinical syndrome, whilst until drawn out in time, is far more consistent with a drug-induced picture than a Bipolar picture’.41
Finally, Dr Apel turns his attention to the question of at what point in non-recurrence can both a bipolar condition and a drug-induced psychosis be considered as efficiently less likely to pose an unacceptable risk to air safety. He makes these findings:
‘At five years after the index episode of a Bipolar illness, the relapse rate is less than 1% and as such it would meet these criteria. If the diagnosis was one of a drug- induced state, the relapse rate is essentially negligible in the setting of abstinence and the absence of the diagnosis of cannabis use disorder. On this score, we have essentially the good word of Mr Walker…’.42
38 A8, p. 18.
39 A8, p. 19.
40 A8, p. 19.
41 A8, p. 19.
42 A8, p. 20.
Dr Robert Liddell describes himself as a ‘…specialist in Aviation Medicine’,43 who says he ‘… has practiced [sic] for 50 years.44 His two reports are respectively dated 16 February 2024 and 8 May 2024 and relevantly appear in the material.45 In the first of his two reports, Dr Liddell answers specific questions put to him by the Applicant’s then legal representatives.
The first of these questions was whether the Applicant meets the medical requirements for a Class 2 Medical Certificate. Dr Liddell agreed the Applicant did not meet this standard in October 2018 following his return from Mexico and his subsequent admission to the Geelong Hospital. However, by the date of his first report (February 2024), Dr Liddell said ‘Having read the reports submitted and examined [the Applicant] at a meeting in Perth in February 2024, it is clear that [the Applicant] now meets the standard for a class 2 aviation medical certificate’.46
The second question was about the type of conditions (if any) to be placed on a medical certificate issued to the Applicant now. Dr Liddell said ‘… in my opinion, to ensure against the very small chance of a relapse, I would require that spot drug testing be performed at a random interval every 3 months for the first 2 years that he holds a class 2 medical certificate. This is in addition to the random spot drug and alcohol testing that CASA already perform on the industry’.47
The third question asked Dr Liddell whether the Applicant’s medical history poses a risk to the safety of air navigation. Dr Liddell recounted the Applicant’s history and solely refers to Dr McConnell’s treatment of the Applicant. Specifically, Dr Liddell focused on Dr McConnell’s finding in December 2018 – about a month after the Applicant’s release from the Geelong Hospital – that ‘Dr McConnell noted that on examination at that time [the Applicant] did not show signs of any concerning psychiatric illness’.48 On this basis, Dr Liddell opined thus: ‘I conclude that apart from the aberration of a short period of relatively
43 A4, p. 1.
44 A4, p. 1.
45 A4, A5.
46 A5, p. 2
47 A4, p. 2.
48 A4, p. 3.
short period of drug use and its effect on his personality, [the Applicant’s] normal state would not constitute a risk to the safety of air navigation.49
The fourth question addressed by Dr Liddell related to the risk of recurrence of the Applicant’s manic symptoms now representing a disqualifying condition for the class 2 certification sought by the Applicant. Dr Liddell takes issue with Dr Atherton’s diagnosis of bipolar disorder but says even if that diagnosis is correct, then the risk of recurrence of the Applicant’s past symptoms would not disqualify him from a class 2 certification. This is because (says Dr Liddell) ‘… the research paper and graph by Hett and Marwaha50 which [Dr Atherton] quotes in his report is used to look at the incidence of recurrence of mania in a bipolar individual, then the risk of recurrence at 6 years is in the order of 1%. This 1% target is the accepted risk target in class 1 (professional pilot) medical certification for a sudden and complete incapacitation from any condition be it heart attack or psychotic episode. In class 2 medical certification, the risk target ranges from 2 to 5% depending on those making the decision.51
The fifth question asked whether he (Dr Liddell) agreed with Dr Atherton’s opinion about the course of the Applicant’s manic episode in 2018. After initially saying ‘I am not a specialist psychiatrist’,52 Dr Liddell appears to disagree with Dr Atherton’s opinion on these grounds:
·the ‘majority opinion’53 of the psychiatrists involved in this case is that the Applicant suffered a drug-induced psychosis;
·medicine ‘is not an exact science’54 and that drug-induced episodes may be of shorter or longer duration;
·there is emerging evidence that ‘… cannabis is now some 100% stronger in its potency than several years ago, and reactions are now more extreme’55;
49 A4, p. 3.
50 R9.
51 A4, p. 4.
52 A4, p. 4.
53 A4, p. 4.
54 A4, p. 4.
55 A4, p. 4.
·Dr Atherton bases his diagnosis ‘almost entirely’56 on DSM 5 criteria for Bipolar Disorder Type 1. There being no depressive component to the Applicant’s psychotic event in 2018, Dr Atherton’s opinion can now be impugned because ‘…the diagnosis of bipolar disorder without a depressive component is not common’.57
Dr Liddell’s report concludes with him saying the Applicant ‘… suffered an acute medical condition which was fully resolved within a few months’.58 Dr Liddell thinks that ‘Now in the sixth year since this disruption to his otherwise normal life, it would be difficult to say he represents any risk to the safety of air navigation’.59
Dr Liddell’s second report (8 May 2024) essentially comprises a response to the report of Dr Elizabeth Ryan dated 12 March 2024. He initially takes issue with Dr Ryan’s methodology behind the calculation of risk in aeromedical decisions, in particular, the concept of ‘absolute’ risk involving a person’s risk of developing an incapacitating condition over a period of time as opposed to a person’s ‘relative’ risk which involved a comparison of such a risk materialising in two different groups of people. Dr Liddell seeks to impugn the incapacitation (or absolute) risk assessment because it ‘…related only to professional pilot operations and to cardiology’.60 He adds that:
‘…the 1% risk of incapacitation per year has been picked up by regulators in western nations and used as an approximate target in certification of air crew in professional operations (i.e. Class One Medical Certificate holders). The risk criterion was not at any stage expected to be used for recreational or non-professional flying’.61
Dr Liddell then takes issue with Dr Ryan’s reliance on the DSM-5 definitions of mania, bipolar disorder, and substance-induced psychotic disorder in reaching a diagnosis about the Applicant’s psychiatric condition. He regards the DSM-5 as ‘…not infallible and intended as a guide to diagnosis to enable common agreement across the speciality when referring
56 A4, p. 4.
57 A4, p. 4.
58 A4, p. 5.
59 A4, p. 5.
60 A5, p. 2.
61 A5, p. 2.
to psychiatric conditions’.62 Dr Liddell concedes that during his period of psychosis, (i.e. the 2018 episode) the Applicant met enough of the DSM-5 criteria for that episode to be labelled as a psychosis. However, Dr Liddell seeks to counterpoint that concession by referring to item D of the DSM-5 definition of ‘Manic episode’ which stipulates that for something to qualify as a manic episode, the episode should not be attributable to the effects of a substance such as a drug of abuse. In the instant case, Dr Liddell says the undisputed factual circumstances of the Applicant’s drug use leading up to the incident in Mexico in 2018 ‘…discounts a diagnosis of psychosis which would otherwise open the door to the question of bipolar disorder 1, as it is indisputable that he was in a drug-induced psychotic episode’.63
Dr Liddell agrees that the DSM-5 provides for a diagnosis of a psychotic disorder that is not substance induced but that none of these conditions are met by this Applicant. First, there is no evidence that the Applicant’s symptoms preceded the onset of substance abuse. Second, the Applicant’s symptoms did not continue for a substantial period after withdrawal. Dr Liddell notes the Applicant ‘...normalised well before the [Geelong] hospital was prepared to release him’.64 Third, there is no other evidence suggestive of the existence of an independent substance induced psychotic disorder. Dr Liddell thus concludes that ‘…the medical history…strongly supports the likelihood the episode was triggered by an over- indulgence in illicit drugs’.65
Dr Liddell disagrees with Dr Ryan on the rate of recurrent risk of the Applicant experiencing a similar episode. Dr Liddell relied on a recurrent risk of <1% which he took from the abovementioned article by Hett et al.66 Dr Ryan said it was unclear how Dr Liddell calculated this figure and considered the figure ‘unlikely’.67 Dr Liddell’s response is ‘I do not believe the risk of recurrence is relevant because I do not believe that BAD [Bipolar Affective Disorder] is the diagnosis supported by the majority of psychiatrists who have examined [the Applicant] or reviewed his medical notes’.68
62 A5, p. 2.
63 A5, p. 2.
64 A5, p. 3.
65 A5, p. 3.
66 R9.
67 R5, p. 13, [33].
68 A5, p. 4.
The next point of difference between Dr Liddell and findings of Dr Ryan relates to (1) her assessment of the duration of the Applicant’s psychotic symptoms and (2) the level of severity of the Applicant’s symptoms relative to the nature and quantity of illicit drugs the Applicant admitted to using at that time. With reference to the former, Dr Ryan thought ‘the episode persisted for several months after the substances were ceased’.69 With regard to the latter, Dr Ryan opined that ‘…the symptoms were significantly more severe than what would be expected from intoxication of the substances used in the quantities admitted’.70
Both of these findings drew a sharp response from Dr Liddell. He thought ‘The actual length of the episode was considerably shorter than the several months mentioned by Dr Ryan’.71 He also thought:
There is no evidence from the reports of the specialist psychiatrists to support the comment of Dr Ryan that [the Applicant’s] symptoms were more severe than expected from the substance abuse. For a drug naïve person to go from zero to daily smoking strong marijuana over a period of several months makes the possibility of drug induced psychosis of a severe nature a significant risk.72
Finally, Dr Liddell discusses the possibility of the Respondent placing conditions on any medical certificate issued to the Applicant. He referred to the imposition of a regime of drug testing being imposed by the Respondent on many other occasions in the past. Such testing, says Dr Liddell has included urinary spot testing and hair testing.
Dr Elizabeth Ryan is a Senior Medical Officer employed by the Respondent on a part-time basis. Her relevant professional background and experience appears in her report. Her duties with the Respondent include (a) review of difficult aeromedical certificate cases and the making of decisions in such cases and (b) liaison with medical examiners and industry. Dr Ryan is the decision-maker who made the Decision Under Review.
Her report helpfully provides an outline of the methodology for calculation of risk in aeromedical decisions. She describes this process as a requirement to assess ‘absolute’ risk which she describes as ‘…the risk of developing an incapacitating condition over a
69 R5, p. 14, [36].
70 R5, p. 14, [36].
71 A5, p. 3.
72 A5, p. 5.
period of time’.73 She contrasts this methodology of assessment to ‘relative’ risk ‘…which is used to compare the risk into two different groups of people’.74
Dr Ryan explains the temporal element around ‘absolute’ risk methodology in these terms:
‘The risk of incapacitation is often expressed as an annual percentage. For example, a pilot incapacitation risk of ‘1%’ per annum’ means that if there are 100 pilots with an identical condition, one of them would be predicted to become incapacitated at some time during the next 12 months (and 99 would not)’.75
This is the risk assessment methodology adopted by Dr Ryan in determining whether an applicant’s condition is ‘safety relevant’ having regard to the criteria of a particular medical standard. The decision-making process involves, first, a determination of whether an applicant for a medical certificate meets the relevant standard. If the applicant does not meet that standard, then second, it is necessary to decide the extent to which the standard is not met. Then third, whether the extent to which the standard is not met is likely to endanger the safety of air navigation.
This third element of the decisional process is guided by numerical criteria. Dr Ryan describes these criteria as ‘a boundary’ for ascertaining the level of normally acceptable risk for commercial or private operation of aircraft. Dr Ryan puts it thus:
‘The normally acceptable risks for a commercial operation, requiring Class 1 Medical Certificate, are in the range of 1-2% (annual risk of an event that can cause incapacitation). The normally acceptable risks for a private operation, requiring Class 2 Medical Certificate, are in the range of 2-5%. Usually, a pilot at the lower range can expect to get unrestricted certification and those above the lower limit can expect to have some conditions placed on the Medical Certificate.76
Dr Ryan points out that while numerical criteria are of assistance to assessing the extent to which an applicant’s failure to meet the relevant standard is likely to endanger the safety of air navigation, those numerical criteria are not the ultimate determinants. She adds that ‘…because of the many variables in each different case, the ultimate decision is made on
73 R5, p. 7, [15].
74 R5, p. 7, [15].
75 R5, p. 7, [16].
76 R5, p. 8, [18].
the basis of a judgment as to whether there is a real and substantial (and not trivial) risk to the safety of air navigation’.77
This judgment comes with the following qualification:
‘For example, where an annual risk of pilot incapacitation is relatively high (for example, 4%) but the incapacity is passive, a CASA medical officer may decide that conditions imposed on a Medical Certificate are capable of adequately controlling the risk, versus outright refusal to issue a Medical Certificate.78
Dr Ryan then reviewed the medical evidence before her with a specific focus on whether the episode experienced by the Applicant in the latter part of 2018 should now be attributed to a substance-induced psychotic disorder or a manic episode with psychotic features and therefore consistent with bipolar 1 disorder. Prior to reviewing that medical evidence, Dr Ryan set out the DSM-5 definitions of mania, bipolar disorder, and substance induced psychotic disorder. For referential context, it is worth setting out these definitions in full.
‘…
DSM-5 definitions of mania, bipolar disorder, and substance-induced psychotic disorder
24.Manic episode:
A. A distinct period of abnormally and persistently elevated, expansive, or irritable mood and abnormally and persistently increased activity or energy, lasting at least one week and present most of the day, nearly every day (or any duration if hospitalization is necessary).
B. During the period of mood disturbance and increased energy or activity, three (or more) of the following symptoms (four if the mood is only irritable) are present to a significant degree and represent a noticeable change from usual behaviour:
1) Inflated self-esteem or grandiosity.
2) Decreased need for sleep (e.g., feels rested after only three hours of sleep).
3) More talkative than usual or pressure to keep talking.
77 R5, p. 8, [20]; adopting this Tribunal’s comments in Collins and Civil Aviation Safety Authority [2017] AATA 2564 at [72] –[76].
78 R5, p. 8, [20].
4) Flight of ideas or subjective experience that thoughts are racing.
5) Distractibility (ie, attention too easily drawn to unimportant or irrelevant external stimuli), as reported or observed.
6) Increase in goal-directed activity (either socially, at work or school, or
sexually) or psychomotor agitation (ie, purposeless non-goal-directed activity).
7) Excessive involvement in activities that have a high potential for painful consequences (eg, engaging in unrestrained buying sprees, sexual indiscretions, or foolish business investments).
C. The mood disturbance is sufficiently severe to cause marked impairment in social or occupational functioning or to necessitate hospitalization to prevent harm to self or others, or there are psychotic features.
D.The episode is not attributable to the physiological effects of a substance
(eg, a drug of abuse, a medication, other treatment) or to another medical condition.
NOTE: A full manic episode that emerges during antidepressant
treatment (eg, medication, electroconvulsive therapy) but persists at a fully syndromal level beyond the physiological effect of that treatment is sufficient evidence for a manic episode and, therefore, a bipolar I diagnosis.
NOTE: Criteria A through D constitute a manic episode. At least one lifetime manic episode is required for the diagnosis of bipolar I disorder.
25.Bipolar I Disorder:
For a diagnosis of bipolar I disorder, it is necessary to meet the following criteria for a manic episode. The manic episode may have been preceded by and may be followed by hypomanic or major depressive episodes.
26.Substance-induced psychotic disorder
(extract) The disturbance is not better accounted for by a psychotic disorder that is not substance induced. Evidence that the symptoms are better accounted for by a psychotic disorder that is not substance induced might include the following: the symptoms precede the onset of the substance use (or medication use); the symptoms persist for a substantial period of time (e.g., about a month) after the cessation of acute withdrawal or severe intoxication, or are substantially in excess of what would be expected given the type or amount of the substance used or the duration of use; or there is
other evidence that suggests the existence of an independent nonsubstance- induced psychotic disorder’.79
First, Dr Ryan had regard to the report of Dr Brook Burchgart (psychiatrist) dated 12 April 2023.80 Saliently, Dr Ryan noted Dr Burchgart’s findings that the Applicant’s episode in late 2018 constituted a ‘…DSM manic episode, severe, with psychotic features…’81 and that ‘Given that the manic symptoms persisted for a period of time after the psychoactive substance (cannabis) was reportedly ceased, a substance induced mood disorder is a possible, but less convincing differential diagnosis’.82 [My emphasis].
Second, Dr Ryan had regard to the report of Dr McConnell dated 16 November 2022, wherein Dr McConnell noted the Applicant ‘had a one off ‘first’ manic episode with psychotic features during 2018. This occurred in the context of recreational drug use during 2018’.83
Third, Dr Ryan reviewed the opinion of Dr Atherton (psychiatrist) dated 22 December 2023. She specifically quoted the findings of Dr Atherton:
‘…
"Unfortunately, it is my expert opinion that he meets the criteria for bipolar disorder and has suffered a severe manic psychotic episode in 2018 when he was extremely behaviourally disturbed and made decisions which put himself and others at risk.
In light of this, I do not believe that the risks of a further episode can be mitigated by any specific criteria applied to his registration at this stage, and he will continue to present with an unacceptable risk of relapse to manic psychosis.
I do not believe that given the nature of the episode and the duration of treatment required, including with the depot medication beyond the period of time in hospital, that this was solely the result of substance ingestion.
Therefore, the diagnosis remains a bipolar disorder type 1.
79 R5, pp. 9-10, [24] – [26].
80 R1, pp 373 – 381.
81 R1, p. 380.
82 R1, p. 381.
83 R1, p. 258.
I am not aware of any global Civil Aviation Jurisdictions which allow Class 1 and Class II Medical Certificates in the context of a diagnosis of bipolar disorder due to the inherently accepted risks of relapse, and the inherently accepted cognitive and safety issues which present in the context of psychosis and manic mood disturbance. This is always an extremely difficult situation for aviators to understand, and my condolences rest with Mr Walker’.84
Fourth, Dr Ryan refers to the report of Dr Robert Liddell of 16 February 2023. She challenges Dr Liddell’s findings as follows:
·Dr Ryan does not agree with Dr Liddell’s opinion that a diagnosis of bipolar disorder with a depressive component is not common and that Cannabis Use Disorder is an alternative diagnosis. She says: ‘The diagnosis of bipolar 1 disorder without depression ranges from approximately 5 to 7.2%, occurring more often in male patients with younger age of onset and psychotic features85;
·with reference to the ‘alternate’ diagnosis of Cannabis Use Disorder, Dr Ryan points out this ‘…is not an alternative but rather an additional diagnosis’86;
·Dr Ryan takes issue with Dr Liddell’s opinion that the Applicant experienced a drug-induced episode of mania and psychosis and, in particular, with Dr Liddell’s apparent reliance on the opinions of other psychiatrists whom he suggests support his views. Dr Ryan points out that Dr Liddell is unresponsive about Dr Burchgart’s diagnosis that (1) the Applicant experienced ‘a single manic episode, severe, with psychotic features’, and (2) that a substance-induced mood disorder is a less convincing diagnosis. Dr Ryan also takes issue with Dr Liddell’s suggestion that Drs McConnell and Atherton support the opinion of the Applicant suffering a drug- induced episode of mania and psychosis. She points out (in my respectful view, correctly) that both Drs McConnell and Atherton (and, for that matter, Dr Burchgart) do not accept the Applicant experienced a drug-induced episode in
84 R5, pp. 11-13, [30].
85 R5, p. 12, [31].
86 R5, p. 12, [31].
2018 ‘…but rather a first manic episode, therefore consistent with the diagnosis of bipolar 1 disorder’.87
·Dr Ryan Also takes issue with Dr Liddell’s assessment of there being a risk of recurrence of less than 1% which he (Dr Liddell) based on the data contained in the Hett et al report.88 The relevant portion of that report reads as follows:
‘Results Relapse rate
The analysed cohort consisted of 2649 patients, aged ≥ 18 years old, and with a diagnosis of BD [bipolar disorder] …as of June 2014. The mean age of the cohort was 54.26 years old (SD = 16.31)89, and the majority were coded as female (61.30%). From this sample, there was evidence of 1248 relapse instances within the 5-year period. These relapses then equated to 676 individual patients in total (as some individuals had experienced multiple relapse referrals) who had experienced at least one episode of relapse within the 5-year period (i.e. relapsers). Thus, based on this data, the 5-year relapse rate for those who had experienced at least one relapse was calculated at 25.52%. More specifically, out of the total sample, 15.55% [i.e of the total cohort of 2649 = 412] experienced one relapse episode, whereas 9.97% [i.e of the total cohort of 2649 = 264] experienced multiple relapses (i.e. at least 2) …. From this point on, patients who had experienced at least one episode of relapse are referred to as relapsers [i.e. 412+264 = 676], whereas those who did not experience a relapse are referred to as non-relapsers [i.e 2649 – 676 = 1973]. Lastly, from the baseline sample, 7.2% [i.e of the total cohort of 2649 = 190] of BD patients were reported to have died during the 5-year period (causes of death unknown). Based on available data around patient’s deaths, the mean age of death was calculated to be 69.19 (SD = 16.43; Mdn = 71) and the mean time (years) from age at earliest reported BD diagnosis to death was 4.49 (SD = 2.43)’. 90
[Bold is in the original; underlined portions appear in italics in the original]
Dr Ryan notes that Dr Liddell does not indicate how he arrived at a measurement of a risk of recurrence of <1% which she considers ‘…unlikely, as the raw data is not available’.91 She is of the view that ‘… Dr Liddell’s extrapolation seems to not refer to the risk of relapse after 5 years possibly being <1%, but rather that less than 1 patient relapsed more than six
87 R5, pp.12 – 13, [32].
88 R9.
89 Denoting ‘Standard deviation’ meaning the amount of variability, or dispersion, from the individual data values to the mean.
90 R9, p. 6.
91 R5, p. 13, [33].
times in the 5-year study period’.92 She notes that ‘This does nothing to confirm an acceptable risk, and this table does not refer to risk over time’.93 [My emphasis].
Dr Ryan makes reference to the figure of 7.2% of study participants who died during the five-year duration of the study period. She notes (1) the report does not mention anything about the cause of those deaths which may have been as a result of a relapse; (2) that this particular study showed lower rates of relapse than previous studies but this may have been due to lower rates of substance misuse in this particular cohort of 2649 patients; and (3) this study is likely to have underestimated the relapse rate because it records as relapses only those patients that were referred to hospital or crisis services upon a relapse; and (4) that only 60% of relapses involved re-admissions to hospitals. Based on these factors, Dr Ryan reaches the following finding:
With these limitations and reasons for an underestimate, especially in the context of aeromedical safety, the risk of relapse remained 25.52% over the 5-year period (Hett et al, 2023). It is therefore not agreed that Mr Walker's risk of a relapse that could affect his ability to safely pilot an aircraft is now less than 1 % based on this study, and not agreed that the risk is at an acceptable level.94
In the next portion of her report, Dr Ryan addresses the question of whether the Applicant meets the Class 2 Medical Standard. She is satisfied that the Applicant ‘…has an established medical history of manic episode with psychosis, which is therefore consistent with a diagnosis of bipolar 1 disorder.95 She does not accept that the episode suffered by the Applicant in late 2018 represented a drug-induced psychosis. She supports this opinion by reference to (1) the episode having persisted for several months after the substances were ceased and (2) the Applicant’s symptoms were significantly more than what would be expected from intoxication of the substances used in the quantities admitted.96
Dr Ryan then addresses the question of whether the Applicant meets the criteria of the medical standard stipulated in Table 67.155 of the CASR. She notes that ‘Although [the Applicant] has recovered from the psychosis episode [i.e. from late 2018], it may recur as
92 R5, p. 13, [33].
93 R5, p. 13, [33].
94 R5, p. 13, [34].
95 R5, p. 14, [35].
96 See R5, p. 14, [36].
defined in Item 2.1 of Table 67.155 of the CASR.97 She then addresses, for the purposes of making an aeromedical decision such as this, the question of whether this Applicant’s history of mania with psychosis is a medically significant decision such as to now be regarded as ‘safety relevant’ for the purposes of regulation 67.015 of the CASR. Her findings are expressed thus:
‘43. A medically significant condition is defined as safety relevant if it reduces, or is likely to reduce, the ability of someone who has it to exercise a privilege
conferred or to be conferred, or perform a duty imposed or to be imposed, by a licence that he or she holds or has applied for (regulation 67.015 of the CASR).
44. A number of the criteria for the prescribed medical standards in Table 67.155 of the CASR utilise the term "safety-relevant' in referring to a medical condition, disease, effect, etc.
45. An established medical history of having suffered an episode of mania with psychosis is considered to be safety relevant because published studies demonstrate that the occurrence of mania with psychosis produces a not insubstantial risk of recurrence of the condition.
46. The term "likely" becomes important in that there is a need to make a judgement [sic] that a condition "is not likely to endanger the safety of air navigation".
47. A Class 2 Medical Certificate is required to be held by a person exercising the privileges of a private pilot licence. In accordance with regulation 67.015 of the CASR, a condition is 'safety relevant' if it is likely to reduce the ability of the person to exercise the privileges conferred by the license.
48. I consider that the evidence establishes that Mr Walker has suffered from a single manic episode with psychosis which is a condition that carries with it a risk of recurrent episodes of acute confusion, disorientation, and unsafe behaviour.
49. Mania with psychosis is potentially an actively incapacitating event, as defined in Items 2.1 and 2.4 of Table 67.155 of the CASR, which, could be a risk to air safety.
50. It is considered aeromedically reasonable not to allow a person who has suffered from a manic episode with psychosis and has a risk of recurrence,
97 R5, p. 14, [40].
which is likely to affect the person to an extent that is safety relevant, to fly’.98
Dr Ryan also makes reference to the International Civil Aviation Organisation’s standards and procedure manual. She quotes paragraph 9.5.6 of that manual which deals with mood disorders which appears in these terms:
‘A history of mania, whether occurring in isolation or as part of a bipolar disorder, should lead to long-term disqualification. Mania is an unpredictably recurring disorder, which presents with grandiosity, increased energy, euphoria, reduced sleep, distractibility and poor judgement [sic]. It may progress to overt delusions with marked irritability, anger and danger to self and to others. Substance abuse is a fairly common consequence. Although this condition may respond moderately well to mood stabilizing agents, the risk of recurrence is significant and the degree of disruption of performance too great to allow a return to flying or air traffic control duties. When the episode of mania has remitted, the patient often feels as well as before and the reason why he should not assume or resume an aviation career requires a great deal of explanation. However, the significant risk of recurrence even with mood stabilizing medication, along with the degree of disruption of mental function when there is a recurrence, precludes an aviation career’.99
Finally, Dr Ryan concludes her report by, first, providing a concluded opinion about whether she can now issue the Applicant with the Class 2 Medical Certificate that has been denied to him via the Decision Under Review. She notes she can only do so if now satisfied that the extent to which he fails to meet that Medical Standard is not likely to endanger the safety of air navigation. Her findings are expressed this:
55. In this regard, I consider that there is a possibility that Mr Walker will suffer a recurrence of mania whilst in flight. Were Mr Walker to suffer mania whilst at
the controls of an aircraft in flight, then this would pose a clear threat to the safety of air navigation, and thus I have reached the conclusion that, the extent to which Mr Walker fails to meet the Class 2 Medical Standard is such that I cannot issue him with a Medical Certificate under regulation 67.180 of the CASR.
56. For the reasons set out above, I consider that Mr Walker's medical history in 2018 poses a risk that would endanger the safety of air navigation.100
98 R5, pp. 16-17, [43]-[50]
99 R5, p. 17, [51].
100 R5, p. 18, [55]-[56].
Second, Dr Ryan concludes her report by addressing the question of whether she could now, pursuant to regulation 11.056 of the CASR, issue the necessary Medical Certificate to the Applicant but with specific conditions as may be necessary in the interests of the safety of air navigation having regard to the Applicant’s medical condition. Her findings on this second element are expressed thus: ‘Mr Walker, by virtue of his history of mania, remains at present at an aeromedically unacceptable risk of suffering incapacitation from recurrence of the condition and associated risk of subtle or complete incapacitation’.101
Dr Michael Atherton is a significantly experienced psychiatrist who has been engaged in private practice for 15 years at a clinic in Sydney. It goes without saying that he holds all usual and necessary specialist Fellowships. In addition, he holds an Advanced Certificate of Training in Addiction Psychiatry. With particular reference to aeromedical reporting, the following should be noted from one of Dr Atherton’s two reports now before the Tribunal:
I have been involved in providing Aviation industry related, psychiatry and addiction medicine expert opinions for the last 10 years and during that time have seen over
100 aviation cases. I review around two to three aviation cases per week for medicolegal reasons and in my practice, I treat pilots and other aviation employees. I am a founding member of the HIMS program in Australia which is an aviation drug and alcohol monitoring program designed to assist pilots to return to aviation safely once they have an established diagnosis of problematic use of substances. I have provided expert opinion to CASA and the AAT on at least four occasions and I am an FAA (US) accredited addiction psychiatrist.102
Dr Atherton’s two reports are respectively dated 22 December 2023103 and 14 September 2024.104 In the first of those reports, Dr Atherton conducted a fulsome review of the medical documentation before him. He interviewed the Applicant in-person and took a detailed history about his background, his prodromal period in Canada from March 2018 and his history of involvement with alcohol and other drugs. In terms of a mental state examination, Dr Atherton noted the Applicant was a physically fit person with no evidence of form of thought disorder noting that ‘The contents of his thoughts and perceptions were normal’.105
101 R5, p. 18, [58].
102 R6, p. 1.
103 R4.
104 R6.
105 R4, p. 8.
Further, Dr Atherton noted ‘His cognition was tested with a MoCA,106 and he scored 28 out of 30’.107
In terms of a clinical ‘Impression’, Dr Atherton was clear and forthright that the Applicant:
‘…has a DSM5 diagnosis of Bipolar Affective Disorder Type 1 – currently in remission, following a manic episode with psychotic features in 2018 (1). This was characterised by a distinct period of mental state abnormality and persistently elevated expansive mood. This lasted over a week and included an inflated self- esteem and grandiosity, a decreased need for sleep, increased goal directed activity, and excessive involvement in activities that are high potential for painful consequences. His mood was sufficiently severe to cause marked impairment including hospitalisation and was not attributable to the psychological effects of substance.
For a diagnosis of Bipolar 1 Disorder, it is necessary to meet the criteria for a manic episode. It is noted that a manic episode may have been proceeded by and may be followed by hypomanic or major depressive episodes, but it is not required for the diagnosis of Bipolar disorder. It is noted that criteria A to C of the DSM5 diagnostic criteria for Major Depressive Episode, are common in Bipolar 1 Disorder but are not required for the diagnosis of Bipolar 1 Disorder, nor is there a need for several manic episodes.
It is therefore the conclusion that due to the evidence of manic episode with psychotic features, DSM5 criteria are met for Bipolar 1 Disorder. In other words, the criteria were met for at least one manic episode. This episode had mood congruent psychotic features. It is now in full remission, and the most recent episode was mania in 2018.
It should be considered whether this is a substance/medication induced bipolar unrelated disorder as per DSM-5. In making this diagnosis (substance/medication induced bipolar unrelated disorder), there should be evidence in the history and physical examination of the criteria of mania, developing soon after or during an episode of intoxication with substances or withdrawal, or after the exposure to a medication. It should be recognised that the involved substance medication is capable of producing the symptoms of mania with psychotic features. I believe it would be extremely unlikely for any amount of cannabis to cause such a profound and long lasting mental disturbance as was seen in Mr Walker’s case’. 108
[Bold and underline is bold in the original; non-underlined bold is my emphasis]
Dr Atherton then addressed a series of questions put to him by the Respondent’s representatives. First, he was asked to confirm his most likely diagnosis for the Applicant.
106 Denoting: ‘Montreal Cognitive Assessment’.
107 R4, p. 8.
108 R4, p. 9.
He was clear that: ‘The correct diagnosis is bipolar disorder type 1 as indicated by the presence of a significant severe manic episode with psychotic features which occurred in 2018 and was present for at least two months, commencing around 2nd October 2018’.109 Second, he was asked to express an opinion on the annualised risk of the Applicant suffering from a further manic episode. Dr Atherton referred to a couple of studies, the first of which noted that bipolar disorder is a recurrent lifelong illness with high risks of disability and excess mortality. In this first report referred to by Dr Atherton, it was noted that: ‘The relapse rate in naturalistic studies was 55.2% …. In randomised control trials, the recurrence rate was 39.3%. This was in individuals on mood stabilising medication, whereas 60.6% of individuals on placebo relapsed’.110 The second study referred to by Dr Atherton was the abovementioned study by Hett et al111 which ‘…found that about one in four people with bipolar disorder in a large sample who were receiving secondary mental health services in the UK relapsed during this five-year period’.112
Third, Dr Atherton was asked to express an opinion on whether it was possible to reduce the Applicant’s risk of suffering a future manic episode. Dr Atherton noted several factors mitigating this future risk comprising: (1) the Applicant’s healthy lifestyle; (2) his very limited use of substances including alcohol; and (3) his stable personal relationship. As against that, Dr Atherton noted the Applicant (1) ‘…lives a life which is high on adrenaline and risk- taking which potentially has concerns related to increased risk of relapse to mania’113; and
(2) that the Applicant travels to overseas countries ‘…which means there are risks associated with impacts on his sleep’.114
Fourth, Dr Atherton was asked to assume that if there were no change in the Applicant’s condition and, in those circumstances, he was asked to express a view about the Applicant’s risk of recurrence five and 10 years since the initial episode. With further reference to the Hett et al study, Dr Atherton noted: ‘…the risk of relapse does appear to reduce over longer periods of monitoring, with most relapses occurring in the early stages of recovery…’.115 Dr
109 R4, p. 10.
110 R4, p. 10.
111 R9.
112 R4, p. 10.
113 R4, p. 10.
114 R4, p. 10.
115 R4, p. 11.
Atherton’s concluded view is that: ‘there is an ongoing risk of relapse which is significant up to and including five years of follow up and the risk of relapse for individuals who have previously suffered with an episode of bipolar disorder will always remain much higher than the general population’.116
Fifth, Dr Atherton was asked whether he thought the Applicant’s manic episode in late 2018 was the direct result of his use of recreational drugs with particular reference to cannabis. It is worth quoting Dr Atherton’s pivotal response in full:
No, I do not believe that his manic episode was the direct result of recreational drugs. Recreational drug use is extremely common in our community and much higher rates of recreational cannabis use exist than do bipolar disorder. It is generally accepted that bipolar disorder including Bipolar I and Bipolar II have a presence of around 2.4% in the general population…. Rates of recreational cannabis use in Australian community are upwards of 30%. For people aged 14 and over in Australia in 2019, 36% had used cannabis in their lifetime and 11.6% had used cannabis in the prior 12 months….
In light of this, the use of recreational cannabis, or even cannabis used on a daily basis does not cause manic episodes. It may cause transient periods of psychological disturbance and in some cases, this can reach the level of psychosis. It will be highly unusual for substance use to trigger an episode which lasts greater than two months and it will therefore not be accepted that this was a substance induced psychotic disorder or mood disorder and I believe it was, in fact, an independent bipolar disorder occurring in the context of significant substance use.
117
[My emphasis]
Sixth, Dr Atherton was asked to assess the Applicant’s risk of resuming a pattern of illicit drug use assuming there are no other changes in his condition. Dr Atherton said: ‘I believe we can say with reasonable confidence that he will remain free of recreational drugs for the next five to 10 years as his use of substances appears to have been relatively succinct and situational’.118
Seventh, Dr Atherton was asked to identify likely symptoms that could result in the Applicant suffering a manic episode while in control of an aircraft. Dr Atherton’s sobering response was put in these terms:
116 R4, p. 11.
117 A4, p. 11.
118 R4, p. 12.
‘Unfortunately, it is likely that if he were to develop a manic episode and to take control of an aircraft, then he would experience significant symptoms by definition which meet the criteria for bipolar disorder. This could be an increase in grandiosity, an increase in sense of wellbeing, racing thoughts, distractibility, and a tendency to engage in goal-directed behaviours without the foresight in relation to risk and activities that could be hazardous.
A manic episode will have a profound impact on his cognitive ability to consider the risks associated with aviation. Given his history of psychosis, it is likely that a manic episode would be accompanied by a complete loss of insight and a refusal to take direction from others as has been the case in the previous example. In the context of his previous manic episode, he refused medication and required treatment under the Mental Health Act and was hospitalised for three weeks. During that time, he needed seclusion and parental medication. He demonstrated very little insight or understanding of his condition and was managed under the Mental Health Act. He also disobeyed direct instruction to not drive a motor vehicle some months after he was discharged and still displayed symptoms of hypomania. He performed a U-turn, whilst towing a caravan and this resulted in a serious crash. Again, the evidence supports poor judgement and insight as well as risk taking behaviour long after the cessation of cannabis and a failure to take clear instruction’.119
[My emphasis]
Finally, Dr Atherton was asked to provide any additional comments he thought relevant and appropriate based upon the material briefed to him and his examination of the Applicant. Dr Atherton’s concluding remarks were these:
‘Unfortunately, it is my expert opinion that he meets the criteria for bipolar disorder and has suffered a severe manic psychotic episode in 2018 when he was extremely behaviourally disturbed and made decisions which put himself and others at risk.
In light of this, I do not believe that the risks of a further episode can be mitigated by any specific criteria applied to his registration at this stage, and he will continue to present with an unacceptable risk of relapse to manic psychosis.
I do not believe that given the nature of the episode and the duration of treatment required, including with the depot medication beyond the period of time in hospital, that this was solely the result of substance ingestion.
Therefore, the diagnosis remains a bipolar disorder type 1.
I am not aware of any global Civil Aviation jurisdictions which allow Class 1 and Class II Medical Certificates in the context of a diagnosis of bipolar disorder due to the inherently accepted risks of relapse, and the inherently accepted cognitive and safety issues which present in the context of psychosis and manic mood disturbance. This is always an extremely difficult situation for aviators to understand, and my condolences rest with Mr Walker’.120
119 R4, p. 12.
120 R4, p. 13.
In the second of his reports (dated 14 September 2024), Dr Atherton repeated his ‘…diagnosis of bipolar effective [sic] disorder type one currently in remission… based on a single manic episode with psychotic features in 2018’.121 He expressed agreement ‘..with Dr Ryan that the risk of relapse in bipolar disorder diagnosis remains high and, in fact, well above the 2%-5% accepted level of relapse which is allowed under Class II medical certification’.122 Dr Atherton takes issue with Dr Liddell’s assessment of the Applicant representing a recurrence of <1% on the basis of how he (Dr Liddell) applied the statistical findings from the Hett et al report. Dr Atherton explained the Hett et al findings in these terms123:
In the Hett et all [sic] study in the International Journal of Bipolar Disorders 2023 11:23, Dr Liddel has miss interpreted [sic] the date and in particular the graph provided. The X-axis does not indicate the year of the study but in fact the number of times that individuals enrolled in the study relapsed during a 5 year study period. Some individuals relapsed once and some as many as 7 times. The overall relapse rates for all individuals enrolled in the study was given as 25 % so 75 % didn’t relapse at all. It would be hard to estimate from this data the exact rates of relapse over the next 5-10 years but one could be reassured that it would not be 2-5%. It was most likely be at least >10% but could be much higher. I quote, “Of 2649 patients diagnosed with BD and receiving care from secondary mental health services, 25.5% (n = 676) experienced at least one relapse over 5 years”.124
[Bold is my emphasis; underlined portion is underlined in the original]
Dr Atherton noted several additional things. The first of those was ‘…the florid…nature of this psychosis which occurred over a significant period of time (>4 weeks).125 Dr Atherton added:
By my estimation, the episode commenced around 2 October 2018 and remained without any doubt for at least a one-month period. There is significant evidence to suggest as reported in my initial report that there was ongoing symptomology as late as 13 December 2018. Evidence of the prolonged nature of this condition is the car crash which occurred around 8 November 2018 when Mr Walker was towing a caravan and decided that it was reasonable to perform a U-turn. This accident occurred at a time when Mr Walker was supposed to be restricted from driving due to the presence of his significant mental health episode. In his response to this incident, he appeared overly optimistic about what happened, despite this being presumably an extremely dangerous event.126
121 R6, p. 2.
122 R6, p. 2.
123 Note to reader: Dr Atherton is referring to Figure 1 on page 6 of 11 of the Hett et al report.
124 R6, p. 2.
125 R6, p. 3.
126 R6, pp 3-4.
Second, Dr Atherton noted that on 1 November 2018, the Community Treatment Order (‘CTO’) imposed as a consequence of the episode suffered by the Applicant shortly prior to then was extended for a further six months. Dr Atherton regards this as ‘…an unusual undertaking as, in my experience of working in acute psychiatric hospitals, the use of a CTO…is in itself, unusual’.127 Dr Atherton says this is unusual because the imposition and/or extension of a CTO requires the implementation of enormous resources from the issuing community mental health entity. He also thinks it is unusual because the imposition (and any extension) of a CTO ‘…involves the oversight of the Mental Health Review Tribunal or similar body who will weigh up the evidence and determine whether there is a legal and medical reason to extend such an imposing order’.128
Third, Dr Atherton makes reference to the further review of the Mental Health Review Tribunal’s decision heard on 4 December 2018 which upheld the original decision. He notes that: ‘If in fact, the psychiatrists involved believed that this was a drug induced one-off episode purely due to the ingestion of cannabis, this would again be extremely unusual. It is my view that this indicates the concern to the index event’.129
By way summary, Dr Atherton considers the Applicant has made a solid recovery from the episode he suffered at the end of 2018 and that there appears to be limited evidence of any subsequent psychotic or significant mood episodes since the initial episode in late 2018. That said, Dr Atherton remains:
‘…firmly of the view that given the severity of the condition and the duration of the psychosis that this is not consistent with purely a drug-induced episode. Whether it is viewed as a drug induced psychosis or a bipolar manic psychosis, the risk of subsequent relapsed is still high from the available data. In a nutshell we ask our self as psychiatrists if we had 100 people who had a similar severe psychotic illness requiring antipsychotic medication, mental health Act intervention and a CTO, would we expect <10% of them to have another episode if they didn’t smoke cannabis again? I think we would struggle to find colleagues who would be comfortable with this statement’.130
Critically, Dr Atherton concludes this second report with these observations:
127 R6, p. 4.
128 R6, p. 4.
129 R6, p. 4.
130 R6, p.4.
· The problem with psychosis is that once insight is impaired the rational decision making processes of the brain are impaired. Considerations regarding risk and negative outcomes become blurred and even if the episode is mild there is no doubt this would be safety relevant. I remain of the view that no level of review or psychiatric observation can significantly reduce this risk;131
· I have reviewed cases including for CASA, where individuals have had 10 years between individual episodes, and the reality is that it would be rare for cannabis to induce such a florid and prolonged psychotic experience;132
· It is difficult to say if prolonging the time of review to say 7 or 10 years (with no evidence of relapse) will further reduce the risks to less than 2%, but my view of this situation however difficult for Mr Walker, is that it would not sufficiently reduce the risks to enable him to carry a Class II medical certificate (CASA CASR Part 67).133
[My emphasis and underlining]
CONSIDERATION
I will make the following findings based on the medical evidence I have reviewed. I am satisfied that the Applicant suffered an episode of mania in October 2018 following prolonged use of illicit drugs initially in Canada from March of that year and then, more intensely, during a trip to Mexico closer to him experiencing the subject episode. The nature of the psychotic episode, with particular reference to its extended duration requiring implementation of a CTO in November 2018 and the extension of that CTO for a further 6 months, satisfies me that the index psychotic episode is more consistent with bipolar disorder than a drug-induced psychosis.
I am further satisfied that based upon the findings of Drs Ryan and Atherton, the Applicant does not meet the Class 2 Medical Standard and that the extent to which he does so should now be found to be significant and likely to endanger the safety of air navigation. As noted by Dr Atherton, the difficulty with psychosis is that once an episode impairs the patient’s insight, the rational decision-making processes of the brain are resultingly impaired. In turn, this means that his capacity to assess and have insight into risk and negative outcomes from his conduct (as in flying an aircraft or even towing a caravan, for example) become blurred. Accordingly, I must (and will) adopt the findings of Dr Atherton such that even if the
131 R6, pp 5-6.
132 R6, p. 6.
133 R6, p.6.
Applicant’s psychotic episode in 2018 were found to be mild, there is no doubt that even such a mild episode would be safety-relevant for present purposes.
Each of the clinicians grappled with fixing a level of absolute risk of recurrence. Be that as it may, I am satisfied by (and prefer) the evidence of Drs Ryan and Atherton who, in my respectful view, correctly interpreted the statistical literature on recurrent risk (especially the Hett et al report) and concluded that this Applicant represents a level of risk well in excess of 2%. I am of the view (and I will find) that the weight of the medical evidence unquestionably gravitates towards Drs Ryan and Atherton, both of whom have specialist knowledge and demonstrated historical experience in aeromedical assessment.
Dr Ryan refers to a ‘boundary’ for the numerical criteria referable to the normally accepted risks for a private operation requiring a Class 2 Medical Certificate which ranges between 2-5%. To my mind, Drs Ryan and Atherton successfully impugn the findings of Dr Liddell who thought the Applicant’s risk of recurrence was in the order of <1% based on the Hett et al study. Dr Atherton assesses that risk at 10% which is well beyond the 2-5% threshold or boundary referred to by Dr Ryan.
Given the assessments of recurrent risk of Drs Ryan and Atherton, and given also the nature of the symptomatology deriving from the psychosis experienced by the Applicant, I agree with the Respondent’s contention that there are no conditions that could be imposed on any medical certificate issued to the Applicant that would sufficiently or satisfactorily ameliorate that risk having regard to the paramountcy of aviation safety.134 The oral evidence contains some discussion about possible workable conditions that could be imposed on a Class 2 Medical Certificate for present purposes. To my mind, this evidence was either less than convincing or otherwise went nowhere.
First, the nature of the Applicant’s medical condition must surely preclude the adoption of a safety (or secondary) pilot as a risk mitigation measure. Such is the nature of psychotic episodes that a sufferer’s physical behaviour and disposition is unpredictable during a psychotic event. It is one thing for a safety pilot to assume the aircraft’s controls in the event of someone like the Applicant doubling over from pain as a result of a heart attack or an
134 As appearing at [72] of the Respondent’s written closing submissions. By agreement of the Parties, their respective written closing submissions were not tendered as formal exhibits but rather as aides-memoire.
attack of appendicitis. It is surely something else for a safety pilot being compelled to, firstly, physically restrain a person in the cockpit at the controls experiencing a psychotic event in violent terms, and once that is done, to then, secondly, safely pilot the aircraft.
Second, Dr Liddell spoke of the apparent regularity of auditing conditions for the periodic monitoring of medical conditions such as that suffered by the Applicant. The Respondent says that such recurrent monitoring and assessment should not be viewed as capable of sufficiently ameliorating the risk of in-flight incapacity were the Applicant to again experience a psychotic episode.135 I agree with this contention but do so on the basis of the clinical finding of Dr Atherton who notes that even an initial psychosis impairs insight and that, as a consequence, the rational decision-making processes of the brain are impaired. So while there may be a regime of auditing and testing imposed on the Applicant, were he to experience a psychotic event while at the controls of an aircraft, his capacity to consider, assess and ameliorate risk and negative outcomes at that very moment have become blurred due to the initial psychotic event. I agree with Dr Atherton: ‘…no level of review or psychiatric observation can reduce this risk’.136
DISPOSITION
I return to the three seminal issues for determination by this Tribunal and will address each in turn. First, does this Applicant meet the medical standard for this issue of a Class 2 Medical Certificate? I have accepted the clinical findings of Drs Ryan and Atherton over and above the other medical evidence before me. For reasons identified by both of those clinicians (which I adopt) this Applicant’s demonstrated history of mania with psychosis is such as to now render that condition ‘safety-relevant’ for aeromedical purposes. I am of the view, and I will find, that the Applicant does not meet the medical standard in item 2.4 of CASR Table 67.155.
Second, is the extent to which the Applicant does not meet the standard a danger to aviation safety? I return to this Tribunal’s (differently constituted) comments in Mulholland:
‘Whether Mr Mulholland has a high risk or a low risk of losing consciousness while flying an aircraft is simply irrelevant. The fact is that he has a risk of incapacitation
135 See the Respondent’s writing closing submissions, p. 14, [75(c)].
136 R6, p. 6.
which is significantly different to the remainder of the aviator population who do not suffer from syncope or any other safety relevant medical condition…’.137
To my mind, the crux of the evidence responsive to this question lies in resolution of the question of whether the Applicant’s severe manic episode in late 2018 is attributable to (1) a drug-induced psychosis; or (2) whether those symptoms could now be found to meet the criteria for bipolar disorder. I have preferred the evidence of Drs Ryan and Atherton and I am firmly of the view that the correct diagnosis remains a bipolar disorder type 1. Having made this finding, one must then consider the extent to which the Applicant does not meet the standard now constitutes an unacceptable danger to aviation safety. The answer to this question is to be found in the findings of Dr Atherton who opined that:
‘The problem with psychosis is that once insight is impaired the rational decision making processes of the brain are impaired. Considerations regarding risk and negative outcomes become blurred and even if the episode is mild there is no doubt this would be safety relevant. I remain of the view that no level of review or psychiatric observation can significantly reduce this risk’. 138
Third, are there any conditions that would reasonably ameliorate the threat to the safety of air navigation? The Respondent notes that conditions may be attached to a Basic Class 2 Medical Certificate following necessary assessment. But that is not the certificate sought by this Applicant. While there may be capacity within the Respondent to issue a medical certificate subject to conditions, that power must be surely subject to current and expert clinical opinion. I have, at several earlier points in this decision, referred to Dr Atherton’s finding that psychosis impairs insight and, in turn, impairs the rational decision making processes of the brain. Even a mild psychotic episode blurs the sufferer’s capacity to consider, assess and ameliorate negative outcomes from an activity in which the sufferer is engaged. Given this clinical reality, it would, in my respectful view, take a bold regulator to issue a conditional Class 2 Medical Certificate in the present case.
DECISION
The Tribunal will affirm the Decision Under Review. I so order.
137 [2007] AATA 1952 at [65].
138 R6, pp 5-6.
Dates of hearing: 11, 12, 25 and 29 November 2024 Applicant’s representation: Self-represented (with support person)
Counsel for the Respondent: Mr Ian Harvey Esq.,
Barrister-at-law Solicitor for the Respondent: Ms Carol Swain
Principal Lawyer, CASA
ANNEXURE A
EXHIBIT LIST
File No 2023/4282
Between Matthew Walker (Applicant)
And Civil Aviation Safety Authority (Respondent)
EXHIBIT
DESCRIPTION OF EVIDENCE
DATE OF DOCUMENT
DATE RECEIVED
RESPONDENT DOCUMENTS
R1
Section 37 T-Documents
Various
29
September 2024
R2
Statement of Facts, Issues and Contentions (‘SFIC’)
25
September 2024
25
September 2024
R3
Briefing letter from CASA to Dr Atherton
16
November 2023
2 August
2024
R4
Report of Dr Michael Atherton
22
December 2023
15 January
2024
R5
Witness Statement Elizabeth Ryan
of
Dr
12 March
202412 March
2024R6
Supplementary Report Michael Atherton
of
Dr
14
September 2024
25
September 2024
R7
Email correspondence between Charl Rootman (APF) and the Applicant
11
November 2019
11
November 2024
R8
University of Melbourne: Risk Assessment Methodology
June 2023
11
November 2024
R9
Hett et al – article – Rates of relapse – bi-polar disorder
30 June
2023
12
November 2024
EXHIBIT
DESCRIPTION OF EVIDENCE
DATE OF DOCUMENT
DATE RECEIVED
R10
Classes of Medical Certificate
Undated
25
November 2024
APPLICANT’S DOCUMENTS
A1
Applicant’s Statement of Facts, Issues and Contentions (‘SFIC’)
Undated
23 August
2024
A2
Affidavit of the Applicant with Annexures (MJKW1-8)
20 October
2023
20 October
2023
A3
Second Supplementary Affidavit
of the Applicant with Annexure (MJKW9)
25 July
2024
25 July 2024
A4
Report of Dr Robert Liddell
16 February
2024
17 February
2024
A5
Supplementary Report of Dr Robert Liddell
8 May 2024
8 May 2024
A6
Supplementary Report of Dr Stephen McConnell
24 April
202430 April 2024
A7
Affidavit of Daniel Helmy
22 July
2024
22 July 2024
A8
Report of Dr Greg Apel
26 July
2024
26 July 2024
A9
First Supplementary Affidavit of Mr Matthew Walker
3 May 2024
4 May 2024
A10
List of conditions proposed by the Applicant
Undated
15
November 2024
0
2
0