Reubel and Civil Aviation Safety Authority
[2018] AATA 1639
•31 May 2018
Reubel and Civil Aviation Safety Authority [2018] AATA 1639 (31 May 2018)
Division:GENERAL DIVISION
File Number:2016/5995
Re:Gerhard Reubel
APPLICANT
Civil Aviation Safety AuthorityAnd
RESPONDENT
DECISION
Tribunal: John Sosso, Deputy President
Date: 31 May 2018
Place: Canberra
The tribunal affirms the decision under review.
........................................................................
John Sosso, Deputy President
CATCHWORDS
CIVIL AVIATION – conditional class 2 medical certificate – transient ischaemic attack - medical standards – examination of medical evidence – imposition of safety pilot condition for public safety – likelihood of Applicant becoming incapacitated during flight – safety relevant condition – decision under review affirmed
LEGISLATION
Civil Aviation Safety Act 1998
Civil Aviation Safety Regulations 1998
CASES
Collins and Civil Aviation Safety Authority [2017] AATA 2564
Goldstein and Civil Aviation Safety Authority [2016] AATA 57
Hall and Civil Aviation Safety Authority [2004] AATA 21
Mulholland and Civil Aviation Safety Authority [2007] AATA 1952
Neal v Secretary, Department of Transport (1980) 3 ALD 97
Window and Civil Aviation Safety Authority [1999] AATA 525
REASONS FOR DECISION
Deputy President John Sosso
31 May 2018
INTRODUCTION
Mr Gerhard Reubel (the Applicant) is a 62 year old retired veterinary surgeon who on 8 April 2016 applied to the Civil Aviation Safety Authority (the Respondent) for a Class 2 medical certificate. He seeks review of the reconsideration decision of 19 September 2016 (Exhibit 1 T48 pp. 176 – 182) which affirmed an initial decision to issue the Applicant with a Class 2 medical certificate subject to the following condition – Exhibit 1 T3 p. 37:
“Class 2 valid with safety pilot only valid for 12 months”.
The Applicant has been flying fixed wing aircraft since approximately 2003, and he estimated that he averaged 40 -50 flying hours per annum until 2016 – Exhibit 1 T1 p. 9. Since that time the Applicant’s flying hours have markedly decreased due, it is claimed, to the difficulty in recruiting a safety pilot for each flight – p. 9.
A key element of the regulatory regime governing the granting of pilots’ licences is the obtaining of one or more medical certificate(s). There are three classes of medical certificates: class 1, class 2 and class 3 – reg 67.145 Civil Aviation Safety Regulations 1998 (the Regulations). The prescribed medical standards for the issue of the various classes of medical certificates are contained in reg 67.150 (class 1), 67.155 (class 2) and 67.160 (class 3).
Subregulation 61.405(1) provides that the holder of a recreational pilot licence is authorised to exercise the privileges of the licence only if the person has a current class 1 or 2 medical certificate or the person holds a current recreational aviation medical practitioner’s certificate (RAMPC).
The regulatory regime pertaining to RAMPC’s is discussed below.
Subregulation 61.410(1) provides that the holder of a private pilot licence is authorised to exercise the privileges of the licence only if the person holds a current class 1 or 2 medical certificate, with the exception that when exercising the privileges of the licence in a recreational aircraft it is sufficient if the holder has a current RAMPC.
Subregulaton 61.415(1) provides, inter alia, that the holder of a commercial pilot licence is authorised to exercise the privileges of the licence only if the person also holds a class 1 medical certificate.
As a general rule, a class 1 medical certificate remains in force for one year, while a class 2 medical certificate remains in force for four years if the holder is under 40 years of age, or two years if the holder is 40 years or older – reg 67.205(3).
Subpart 77.B of the Regulations provide for the appointment of designated aviation medical examiners (DAME).
When a person applies for a licence, or a renewal of a licence, he or she is usually, required to undergo a relevant medical examination conducted by a DAME – reg. 67.180. The issuing of a medical certificate is dependent on such an examination taking place and compliance with the relevant medical standard “in all respects” – reg 67.205(2).
The Applicant applied for Class 1 and 2 medical certificates in 2011 and the Medical Questionnaire and Examination form was completed by Dr Andrew Pitcher (DAME) on 27 January 2011 – Exhibit 1 T4 pp. 50 - 60. At that time the Applicant had 440 flying hours experience and had flown an estimated 60 hours in the preceding six months – Exhibit 1 T4 p. 50. Dr Pitcher answered in the affirmative to the question whether the Applicant had been diagnosed with high blood pressure, and noted that he had been treated with Valsartan since 2010– pp. 51 - 52.
Valsartin is a drug prescribed, inter alia, for the treatment of hypertension and results in the reduction of blood pressure without affecting the pulse rate – MIMS Annual 2016 2-69.
The Applicant used his medical certificates in the operational context of charter flying and single pilot operations of aircraft with maximum take-off weight of less than 5,700 kg – Statement of Facts and Contentions of the Respondent (SFCR) para 9.
On 21 November 2012, the Applicant, after sitting at his desk for approximately 90 minutes, became dizzy when he got up quickly and experienced “pins and needles” and numbness in his left foot. After conferring with his brother-in-law in Melbourne, he drove to the Canberra Calvary Hospital. The pins and needles and numbness in his left foot persisted. The Applicant’s blood pressure was elevated and he was admitted to the Hospital for investigation – Exhibit 2 p. 1.
The Applicant remained at the Hospital until 23 November 2012. In his Discharge Referral, the Principal Diagnosis was: “7R ACA infarct (further investigation required)” – Exhibit 1 T9 p. 65. Further, under the heading “Clinical Management” the following analysis was made – Exhibit 1 T9 pp. 65 – 66:
“56 year old male presented with ED with left sided leg weakness and dizziness for more than 24 hours.
On examination, power is generally decreased on the left lower limb.
CXR NAD
CTB No acute intracranial pathology (further MRI required)
Carotid dopplers NAD…
Patient was given a stat dose of aspirin 300mg and continued on aspirin 100mg
On day 2 of admission, there are no longer any neurological deficits.
Seen by physiotherapist to ensure safe for discharge.
On advice of the neurology team:
Control risk factors of stroke – lower BP and lower cholesterol (SBP – 140 and LDL 4.5)
Outpatients holter monitor
Outpatients MRI booked for next week (28/11/12)
Continue aspirin 100mg daily
To be followed up in TIA/Stroke clinic with Dr Gawarikar\
Patient advised to have a liver function test done in a weeks time and results to be reviewed by GP as just started on statins.
Patient advised to stop ramipril if feels dizziness and to monitor blood pressure.”
The MRI of the brain booked for 28 November 2012 was performed by Dr Meng Chung. His comments are as follows – Exhibit 1 T9 p. 69:
“Multiple tiny foci of white matter signal throughout the brain. These most likely represent early chronic white matter ischaemic change. No evidence of recent infarction. No features to suggest demyelination.”
On 30 January 2013 Dr Pitcher wrote to Dr Gawarikar, Consultant Neurologist, as follows – Exhibit 1 T12 p. 77:
“Reubel consulted me today with regard to renewing his class 2 aviation medical which involves flying non commercial aircraft. I found him in good health. However CASA makes the final decision on issuing his clearance to fly based on information from investigations and specialists’ reports. Before I forward his medical onto CASA I wonder if you could help by forwarding his holter monitor report, the possible reason for his TIA (? Hypertension), his current neurological status and any other information you would like to add.”
As alluded to in this letter, the Applicant was applying for a Class 2 medical certificate, and the Medical Questionnaire and Examination form was completed by Dr Pitcher on the same day – Exhibit 1 T13 pp. 78 - 87.
Dr Pitcher noted that the Applicant had by 30 January 2013 flown 565 hours, including 35 flying hours time in the previous six months and was seeking to fly as a Single Pilot on fixed wing aircraft of less than 5,700 kg MTOW – pp. 78 - 79. Dr Pitcher also stated that from 21 November 2012 the Applicant was taking aspirin (100 mg), atorvastatin (20 mg), pantoprazole (40 mg) and Ramipril (2.5 mg) – p. 79.
Ramipril is an angiotensin-converting enzyme inhibitor used to treat high blood pressure and congestive heart failure – see MIMS Annual 2016 2-123.
Dr Pitcher also answered in the affirmative to questions whether the Applicant had been diagnosed with high blood pressure and had “Rx for high blood pressure” – p. 80.
In the section of the Questionnaire headed “Neurology”, Dr Pitcher ticked the “No” box for the following symptoms: frequent severe headaches, head injury, unconsciousness, fits, faints, blackouts, funny turns, dizziness, tremors and paralysis”. He ticked the “Yes” box for “weakness of limbs”. In response to the boxes under “Diagnosis”, Dr Pitcher answered in the negative to: stroke, cerebra vascular accident and traumatic brain injury, but affirmative to “Transient ischemic attack” (TIA) – p. 81.
Finally, in the section which allows the provision of additional information, Dr Pitcher made the following comments – Exhibit 1 T13 p. 86:
“See Calvary Hosp. Discharge. Admitted (with) 24 hr left sided leg weakness & dizziness. Decrease power left lower limb. 2 days later full recovery….see report Dr Colin Andrews neurologist 4/03/13”.
Dr Colin Andrews, Consultant Neurologist, examined the Applicant and provided the following report dated 4 March 2013 – Exhibit 1 T14 pp. 89 – 90:
“This gentleman has a Class 2 CASA medical for a private pilot’s licence.
He is a vet who has done science at the CSIRO.
He had a turn on the 27th November 2012 with some left leg weakness and dizziness that lasted about 24 hours and was admitted to Calvary Hospital for a few days.
His CT brain and MRI of brain have been normal, carotid dopplers are normal and echocardiography has been normal
He is not aware of having AF.
He is on full secondary prevention with Aspirin, a statin and blood pressure treatment.
His neurological examination was perfectly normal.
His blood pressure was elevated at 170/90, but I understand he takes his own blood pressure it has been quite normal at 120/80.
The cause of his TIA is not clear but we assume that it is probably embolic off the vessel wall which is the commonest cause.
The future risk on treatment of him subsequently having a stroke is quite low, less than 2% annualised.
It is not my decision that he should fly or not, it is up to the aviation doctor.
I have the discharge summary from the hospital and included in that is his biochemistry, full blood count and blood sugars, all of which are satisfactory.
I have a friend who had a commercial licence who had a TIA and all his investigations proved normal and after a year it looks a though they will let him fly again.”
Dr Gawarikar provided a follow-up report dated 26 March 2013 wherein he diagnosed the Applicant with right hemisphere TIA, hypertension and hypercholesterolemia and noted that his current medications included Aspirin 100 mg daily, Ramipril 2.5 mg daily, Atorvastatin 20 mg daily and Pantoprazole 40 mg daily – Exhibit 1 T16 p. 92. Dr Gawarikar’s report contains the following information – pp. 92 – 93:
“Plan
1. Eligible for Class 2 pilot licence only
I had the pleasure of seeing Gerhard Reubel on the 26th of March 2013 when he came for follow up. He had had an extended three day holter monitor done. This holter monitor did not show any evidence of atrial fibrillation or high grade tachyarrhythmias. It showed occasional ventricular and supraventricular ectopics.
Gerhard has been doing well and has not had any other symptoms.
Opinion:
Gerhard had a right hemisphere TIA. He has been investigated quite thoroughly to the best of our capabilities at this stage. There is no evidence that has paroxysmal atrial fibrillation at this stage. As a result I do not think that he should be anticoagulated. He should continue taking Aspirin 100 mg daily. There is evidence that Assantin and Clpidogrel are marginally superior to Aspirin in reducing risk of strokes and TIAs. I would be happy if he was put on either of these agents or to continue with Aspirin alone. If he remains well I will see him again in 12 months.
He is eligible for a Class 2 pilot’s licence and I am happy for him to fly. He is not eligible for a Class 1 pilot’s licence and is not eligible to fly commercial planes or take passengers with him.”
On 18 April 2013 Dr Michael Drane, an Aviation Medicine Officer of the Respondent, wrote to the Applicant informing him that, on the information then provided, it was proposed not to grant him either a Class 1 or 2 medical certificate. This was on the basis of the Applicant having an established medical history of TIA. Under the heading “Risks to air safety”, Dr Drane made the following comments – Exhibit 1 T 20 p. 100:
“Your condition is associated with the following symptoms which would adversely affect your ability safely to exercise the privileges of your pilot licence:
·Recurrence of cerebrovascular accident or transient ischaemic attack
·Complications of recurrence, eg seizure.
In some circumstances, these risks diminish with time and a new application may be considered 12 months after the index event if recovery has been complete and uneventful, and risks factors are all appropriately managed.”
The Applicant made further submissions to the Respondent in a letter dated 8 May 2013 in which he placed primary reliance on the reports of Dr Andrews and Dr Gawarikar – Exhibit 1 T21 pp. 101 – 102.
On 19 July 2013 Dr Drane refused to issue the Applicant with a Class 2 medical certificate – Exhibit 1 T22 pp. 103 – 105. Dr Drane noted that the Applicant had an established medical history of a transient ischaemic episode and that the applicable medical standard for a Class 2 medical certificate was Medical Standard 2.7 which is prescribed in Table 67.155 of the Regulations. In particular, Dr Drane relied on Item 2.7 which relates to the nervous system:
“2.7 Has no established medical history or clinical diagnosis of:
(a) a safety-relevant disease of the nervous system…”
Dr Drane opined that as the Applicant did not meet the Medical Standard, he could only be granted a Class 2 medical certificate if Dr Drane was satisfied that the extent to which the Applicant failed to meet the medical standard was not likely to endanger the safety of air navigation.
Dr Drane again set out the symptoms associated with the Applicant’s medical condition which were set out above. He then concluded that no additional conditions could be imposed on the medical certificate which would adequately ameliorate the risks to air safety posed by the Applicant’s medical condition. In that regard Dr Drane relied upon two medical articles: Van Wijk et al, ‘Long-term survival and vascular event risk after transient ischaemic attack or minor ischaemic stroke: a cohort study’ Lancet 18 June 2005, Vol 365 pp. 2098-2104 and Hardie, K et al, ‘Ten-year survival after first-ever stroke in the Perth community stroke study’, Stroke 2003 August; 34(8)(B); 1842-1845. Dr Drane stated that the studies highlighted unacceptable risks of incapacitation post TIA, with an annualised risk at over 4% - p. 104.
The van Wijk article was admitted into evidence as marked as Exhibit 7.
The Applicant exercised his right to seek a reconsideration of the decision and provided further information to the Respondent. The reconsideration was conducted by Dr David Fitzgerald, Consultant Occupational Physician, who made the following decision on 1 December 2014 – Exhibit 1 T29 p. 128:
“Having completed the assessment, it is my view that it will be necessary to add restrictions to your medical certificate. This is because of your condition of transient ischaemic attack of uncertain or undetermined cause which creates an unacceptable risk of inflight incapacitation, unless mitigated by an appropriate restriction. Accordingly, it is intended that your medical certificate will be issued subject to a condition(s) imposing the following operational limitation(s).”
The letter does not contain any limitations, only an italicised box which reads: “[insert limitations here].” – p. 128. On 4 December 2014 an email was sent by an officer of the Respondent to the Applicant which clarified the matter – Exhibit 1 T30 p. 132:
“Thank you for your email, I would first like to apologise for the fact that the letter we sent you was incomplete. When it was saved to our medical record system the information reverted back to some of the original text. I have attached your amended letter to this email. The restriction we wanted to put on your certificate is restriction 9 Holder to fly with safety pilot only.
If you want to accept this restriction please let us know and we can finalise your medical application, if not we will wait for further information from you. If you want an extension to the time period we have given to provide this information we will be able to do this as well again just let us know how long you would like.”
The Applicant replied in an email dated 8 December 2014 in which he requested that no decision be made with respect to his Class 2 medical certificate application within the 30 day period, but instead asked “to keep the file open until further medical evidence can be obtained.” – Exhibit 1 T30 p. 130. However, on 13 February 2015 the Applicant emailed the Respondent as follows – Exhibit 1 T30 p. 130:
“Further to my communication asking not to make a decision as I would like the opportunity to get more evidence to show that I do not need the condition of ‘safety pilot’, I currently do not have the time and resources to get the required evidence so will reluctantly at this time accept the stated condition.”
The Respondent wrote to the Applicant on 9 March 2015 informing him that a Class 2 medical certificate valid for 12 months had been issued with the safety pilot qualification. The full terms of the condition were outlined in an attachment – Exhibit 1 T31 pp. 133, 135.
On 8 April 2016, shortly before the expiration of his medical certificate, the Applicant was examined by Dr Pitcher in order to obtain a new class 2 medical certificate – Exhibit 1 T37 p. 143. Prior to being seen by Dr Pitcher, the Applicant was examined by other medical specialists.
The Applicant was further reviewed by Dr Andrews on 23 March 2016. The full text of the report of Dr Andrews is set out below – Exhibit 1 T33 p. 138:
“This gentleman I have seen previously following a mini-stroke from which he has made a recovery. There has been no recurrence.
On review today, 23rd March 2016, he told me that he is still on triple therapy as secondary prevention for TIAs which include a statin, aspirin and his Ramipril.
His neurological examination I found quite satisfactory. There were no carotid bruits and he was in sinus rhythm. The only concern was his blood pressure which was 190/100 but he gets the white-coat syndrome. He does monitor his own blood pressure and it has been in the normal range so I assume that the blood pressure is well controlled.
Given he is taking full secondary prevention medication the risk of him having a stroke is now getting extremely low and I would support him in being a pilot that can take more than one passenger.
I note that he will be seeing Ram Malhotra next week as well to add weight to his application for his pilot’s licence.”
The Applicant was examined by Dr Ram Malhotra, Neurologist, who provided a report dated 1 April 2016. Dr Malhotra made the following observations – Exhibit 1 T36 p. 141:
“Thanks for asking me to see Dr Gerhard Reubel, 60 years old male, who presented with an episode in November 2012. He was sitting on his desk for an hour, got up and felt a bit dizzy. He could move his left leg but he was feeling pins and needles in the left leg. There were no symptoms in the left upper limb, slurred speech or facial droop. The dizziness was gone within five to ten monites (sic) but the pins and needles lasted for up to an hour.
As he was dizzy at the same time he called his brother in Melbourne who asked him to go to his GP. His GP was outstation and therefore he drove himself to the Calvary hospital as he was not dizzy by that time but still had some pins and needles in the left leg. A provisional diagnosis of TIA was considered. He had all the clinical examination and investigations includint (sic) carotid duplex and MRI brain which all came back normal.
The discharge diagnosis was right hemisphere TIA.
Gerhard has background history of HPN, GORD and Hyperlipidaemia.
His regular medications include Aspirin, Atorvastatin, Pentaprazone and Ramipril.
The neurological examination today was normal.
Gerhard is continuing to fly on a CASA driver’s licence medical which is due to run out and he want to continue to fly on a class 2 medical license (non commercial license carrying non paying passengers in general aviation aircraft.)
I am nor sure whether Gerhard had a TIA or just compression of the sciatic nerve from prolonged sitting in one position.
will like to privide (sic) the following information from ‘uptodate’ regarding the risk of recurrent stroke after TIA and the prevention with treatment:-
RISK OF RECURRENT STROKE
As evident from the graph in the following page, the risk of recurrent stroke goes to minimum of almost 3% at three years and then again rises over the next several years to an average risk of around 7%.”
Hyperlipidaemia is a condition in which there are high levels of fat particles (lipids) in the blood. This can result in restricted blood flow thereby increasing the risk of heart attack and stroke.
Dr Pitcher wrote to the “CASA Medical Examiner” on the same day he examined the Applicant and said – Exhibit 1 T38 p. 144:
“Thank you for assessing Dr Gerhard Reubel, age 60 yrs, for further evaluation to hold an unrestricted class 2 medical certificate without a safety pilot. I have enclosed 2 recent reports from local neurologists whom deem Gerhard fit to fly. In fact there is the question whether Gerhard had a TIA at all, the parathesiae in his leg could be attributed to sciatica. Gerhard has maintained excellent health, non drinker and smoker and exercises regularly. His risk of having a stroke is well below the recommended 2% as long as he continues with his antiplatelet and other recommended medication.”
On 13 May 2016 Dr Peter Clem, Senior Medical Officer, wrote to the Applicant informing him that a class 2 medical certificate had been issued for 12 months with a safety pilot restriction – Exhibit 1 T41 pp. 155 – 158. Dr Clem made the following comments in his letter – pp. 155 – 156:
“Your certificate has a shortened duration as CASA needs to establish the stability of your condition in the context of aviation safety.
CASA needs to ensure that your medical condition and/or its treatment do not impact aviation safety with respect to your ability to control an aircraft. Accordingly, CASA is maintaining your audit requirement to monitor the progress of your medical condition. The requirement for continued audit is reviewed at each medical certificate renewal.
If there is any change in your condition or treatment, you are required to ground yourself until cleared by CASA or your DAME to return to flying, in accordance with regulation 67.265 of the Civil Aviation Safety Regulations 1988 (CASR). This includes any adjustments in medication dose or commencement of new medications, to ensure that there are no unforeseen side effects (a ‘ground trial’). Once you have been stabilised on any new medications or doses, your DAME can return you to flying.”
On 16 May 2016, the Applicant sought a reconsideration of this decision and relied on the medical reports of Dr Andrews and Dr Malhotra – Exhibit 1 T43 p. 163.
Following receipt of the reconsideration request, the Respondent commissioned a file review and report from Dr David Fitzgerald, Consultant Occupational Physician and Clinical Senior Lecturer in Aviation and Occupational Medicine of the University of Otago – Exhibit 1 T45 p. 165 – 169.
It will be recalled that Dr Fitzgerald was previously employed by the Respondent and was the officer who made the reconsideration decision of 1 December 2014. His analysis and conclusions, therefore, must be viewed with this background in mind.
After comprehensively outlining the various medical reports and tests discussed above, Dr Fitzgerald said – pp. 168 – 169:
“My view in the circumstances is that allowing solo flight where there is a significantly elevated risk of syncope or seizure in flight is inappropriate, as it risks catastrophic failure of a system of safe flight with respect to Mr Reubel himself, and also to innocent bystanders on the ground.
It is my view that the alternative traditional restriction of ‘valid with safety pilot only’ is more appropriate.
Of note, as evidenced by natural history by the Van Wijk study, Mr Reubel is probably on the uphill slope towards an annualised risk of 7% now he is some 4 years post the initial event. His risk is therefore rising, not falling.
With due respect, Dr Malhotra is in error in applying further risk reductions to the Van Wijk figures on the basis of treatment – the Van Wijk patients were subject to secondary risk reduction already.
Also of note the presence of white matter ischemia on MRI is an independent risk factor for future stroke.
Due to the significant and increasing risk due to these factors, is my view that ‘valid with safety pilot only’ is the more appropriate risk mitigation of the two in this case, and allowing solo flight is not appropriate.
I would further opine though, that as one of the possible presentations of a recurrent stroke is a seizure, it would in in (sic) my view in the circumstances be inappropriate for any form of medical certification due to the active nature of the incapacitation in that event, especially given what seems to be an increasing risk.
Mr Reuben makes the point that he has been flying on a recreational certificate since the 2012 episode. He has it seems been flying illegally as a TIA is a disqualifying condition for a recreational medical…
Summary
In this case as there is a non-trivial risk of future neurologic episodes that is now increasing, I would set aside the decision to issue a medical certificate with the restrictions ‘valid with safety pilot only’ and substitute the decision that CASA should refuse to issue any medical certificate for any class.”
On 19 September 2016 Dr Apama Hedge affirmed the decision of Dr Clem – Exhibit 1 T48 pp. 176 – 182.
On 7 November 2016 the Applicant applied under the Administrative Appeals Tribunal Act 1975 for a review of the decision of Dr Hedge – Exhibit 1 T1 pp. 3 – 8.
Following the application for review, the Applicant was examined by Professor Ernest Somerville, Consultant Neurologist of the Institute of Neurological Sciences, Prince of Wales Hospital, Randwick.
Dr Somerville examined the Applicant on 17 February 2017, and his report of the same date provides the following background information – Exhibit 2 pp. 1 - 2:
“Dr Reubel denied having weakness, despite being prompted that the discharge summary from the hospital does refer to weakness. He had no difficulty walking. There were no sensory symptoms in the face or arm. His sensation returned to normal after about 3 hours. The dizziness was the same sensation that he will experience if he stands up too quickly. The chair he was sitting in was a standard desk chair. He does sometimes cross his legs when using this chair.
There have been no previous sensory episodes except after sitting in certain positions, when he may have pins and needles in either of his upper limbs. He may also experience numbness of the left thumb after playing his saxophone for prolonged periods. He has experienced similar dizziness in the past when getting up after lying underneath a car or an aircraft. He denies palpitations.
He has been intermittently treated for elevated blood pressure. He has been on continuous blood pressure treatment since the event in November 2012 except when he stopped treatment for 7-10 days in early January, in order to assess his blood pressure himself. He found that it was no different. He has had a borderline elevated cholesterol but his HDL:LDL ratio has always been good. There is no history of diabetes…
There is no family history of stroke.”
Dr Somerville’s clinical diagnosis of the November 2012 event was that it “was most likely to have been a transient ischaemic attack” – Exhibit 2 p. 3.
In response to Dr Malhotra’s diagnosis that the November 2012 event may have been a compression of the sciatic nerve from prolonged sitting, Dr Somerville opined – Exhibit 2 p. 3:
“Prolonged sitting in one position can produce numbness and/or pins and needles in the leg or foot through compression of one of the peripheral nerves (including the sciatic nerve). However, it does not normally cause weakness and it usually resolves within minutes. I would therefore think that this is an unlikely explanation of Dr Reuble’s symptoms.”
Professor Somerville was asked by the Respondent what is the Applicant’s current annual risk of mortality and incapacitating co-morbid conditions. His response was as follows – Exhibit 2 pp. 3 -4:
“I assume that ‘incapacitating co-morbid conditions’ refers to stroke, seizure and heart attack. There are a number of published studies on the risk of subsequent stroke and death following a TIA. These provide a range of figures but most indicate a risk of stroke at 5-10% per year. The Dutch study (van Wijk, Lancet 2005) followed almost 2,500 patients for 10 years. This was performed at a time when most patients received secondary preventive treatments (such as aspirin and control of elevated cholesterol and blood pressure). The 10-year risk of death was 43% and of vascular event (stroke or heart attack) 44%. The chance of being alive and free of vascular events at 10 years was 48%. Although there is some variation is risk depending on the time since the initial event, this variation is small beyond the 4 year mark and is of the order of 6-7% per year for vascular events.
The figure used by the American Heart Association and American Stroke Association in their 2014 Guidelines for the Prevention of Stroke in Patients With Stroke and Transient Ischemic Attack was 3-4% per year for recurrent stroke. The figure used by the Royal College of Physicians in their 2016 National Clinical Guidelines for Stroke was 26% at 5 years. There is also an increased risk of death, especially from heart disease, following stroke/TIA. The study used as the reference for the US Guidelines (Dhamoon, Stroke 2007) found a risk of fatal cardiac events of 6% in the 5 years following a stroke.”
The matter was heard in Canberra on 22 February 2018. The Applicant was self-represented, appeared in person and gave evidence. The Respondent was represented by Mr Anthony Carter. In addition to the Applicant, oral evidence was also received from Professor Somerville, Mr Warren Muller and Dr Clem.
THE LEGAL FRAMEWORK
Section 3A of the Act sets out the main object of the legislation as follows:
“The main object of this Act is to establish a regulatory framework for maintaining, enhancing and promoting the safety of civil aviation, with particular emphasis on preventing aviation accidents and incidents.”
Section 8 establishes the Civil Aviation Safety Authority whose functions are enumerated in s 9. Included in those functions is the conducting the safety regulation of civil air operations in Australia including, inter alia, developing, promulgating and enforcing safety standards and issuing certificates, licences, registrations and permits.
Section 9A deals with the performance of those functions:
“(1) In exercising its powers and performing its functions, CASA must regard the safety of air navigation as the most important consideration.
(2) Subject to subsection (1), CASA must exercise its powers and perform its functions in a manner that ensures that, as far as is practicable, the environment is protected from:
(a) the effects of the operation and use of aircraft; and
(b) the effects associated with the operation and use of aircraft.”
It will be noted that the Act mandates the primacy of air safety over all other considerations. This obligation permeates all aspects of the civil aviation regulatory regime. It is the prism through which the Respondent, its employees or agents must focus their endeavours and calibrate their actions. However, it would be a mistake to confuse primacy with dominance or exclusivity. Although air safety is the primary consideration for a decision-maker under the Act or Regulations, it is by no means the only consideration. Other worthy public interest considerations, including cost, efficiency, effectiveness, environmental protection, noise disturbance, public access to aviation services and a viable civil aviation industry, can and should be taken into account. Civil aviation safety considerations do not exclude those matters from a decision-makers purview. However, when safety considerations are at odds with any other consideration, a decision-maker is required to recognise the primacy of safety in the hierarchy of relevant considerations.
Part III of the Act deals with the regulation of civil aviation. Importantly for this matter s 20AB(1)(a) provides that a person must not perform any duty that is essential to the operation of an Australian aircraft during flight time unless the person holds a civil aviation authorisation in force that authorises the person to perform that duty.
The term “civil aviation authorisation” is defined in s 3 to mean an authorisation under the Act or Regulations to undertake a particular activity, which includes, inter alia, an authority, licence or certificate. In short, a civil aviation authorisation, includes a medical certificate.
Subparts 61.E – 61.L of the Regulations deals with pilot licensing. Subpart 61.G governs recreational pilot licences, subpart 61.H private pilot licences and subpart 61.I commercial pilot licences. As would be expected, the higher the class of licence the more prescriptive and rigorous is the regulatory regime.
As previously noted, the holder of a recreational pilot’s licence must have either a current class 1 or 2 medical certificate or a current RAMPC.
A RAMPC is based on a modified unconditional driver’s licence medical certificate for a private motor vehicle. To obtain a RAMPC a pilot must undertake a medical examination by a GP using the criteria issued by the Respondent and then register the certificate with the Respondent.
A pilot relying on a RAMPC has certain restrictions placed on his or her aviation activities. Only a light-weight, single-engine aircraft may be flown, under the visual flight rules, at or below 10,000 feet with passengers restricted to one other person expressly informed about the pilot’s different kind of medical certificate – see Form 166 (A) (B) (C) Guidance.
In addition, reg 61.405(b)(ii) requires that a person holding a RAMPC must also meet the requirements of reg 61.405(2). Importantly, in that regard, the holder must meet the modified Austroads medical standards – reg 61.405(2)(d). Subpart 67.D defines and explains the modified Austroads medical standards. Amongst the medical histories and conditions linked to the modified Austroads medical standards is reg 67.263(2)(f):
“a history of transient ischaemic attack or stroke; “.
The disqualifying medical conditions for a RAMPC are therefore linked to the evolving Austroads disqualifying medical conditions. In this regard, amongst the many medical conditions in the Austroads disqualifying conditions, is TIA. The current Austroads guideline is that an unconditional motor vehicle driver’s licence is not met if the person had a single TIA. Risk of future neurological events increases after one attack giving rise to aviation safety-relevant risks – Form 166(A)(B)(C) Guidance.
Consequently, although the Applicant was able to previously rely on the RAMPC regime to maintain his ability to fly, by early 2016 the occurrence of one TIA prevented the issuance of a RAMPC. Accordingly, the Applicant was required to apply for, and rely upon, the terms of a class 2 medical certificate – Exhibit 1 T1 p. 10.
Part 67 of the Regulations comprehensively prescribes all matters relevant to the medical overview of licensed persons, including the appointment of DAME’s, the issue and control of medical certificates and the provision of offences in relation to the holders of, inter alia, medical certificates.
The system of regulatory aviation medicine in Australia was detailed, and very helpfully explained, by Dr Clem in his 30 January 2018 statement – Exhibit 4 paras 9 – 25. The Tribunal found Dr Clem’s explanation of how the Respondent, and in particular its Office of Aviation Medicine, develops and administers medical standards, to be of great assistance in this matter.
Subpart 11.BA of the Regulations deals with the granting of authorisations etc. Regulation 11.056 allows the Respondent to grant 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.” This power has to be read with reg 11.055(1A) which provides that the Respondent may grant, inter alia, a medical certificate only if:
“(e) granting the authorisation would not be likely to have an adverse effect on the safety of air navigation.”
70. These provisions must be read in conjunction with the regulation dealing with the issuing and refusal to issue medical certificates – reg 67.180. Regulation 67.180(1) directs the Respondent to issue a medical certificate if the applicant meets the requirements of reg 67.180(2). Subregulation (2) outlines a list of requirements that an applicant must meet, including paragraph (e) which provides:
“(e) either:
(i)the applicant meets the relevant medical standard; or
(ii)if the applicant does not meet the standard is not likely to endanger the safety of air navigation.”
First, the criteria for meeting medical standard 2 are set out in Table 67.155 of the Regulations.
Items 2.1 – 2.2 and 2.7 provide as follows:
“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 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.
2.2 Has no physical conditions or limitations that are safety-relevant.
Nervous system
2.7 Has no established medical history or clinical diagnosis of:
(a) a safety-relevant disease of the nervous system; or
(b) epilepsy; or
(c) a disturbance of consciousness for which there is no satisfactory medical explanation and which may recur.”
The term “safety-relevant” is defined by reg 67.015 as follows:
“For the purposes of this Part, a medically significant condition is 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.”
The phrase “medically significant condition” is defined by reg 67.010 to include:
“(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 (1), (ii) or (iii)…”
It should be noted that the definition specifically qualifies subparagraphs (i) – (Iv) by the words “no matter how small”. It follows then, that the definition has been deliberately drafted to give it the broadest possible effect.
There is a considerable body of Tribunal jurisprudence on the preferable interpretation of “likely” in the context of Part 67 of the Regulations.
Reference can be made to Window and Civil Aviation Safety Authority [1999] AATA 525 where the Tribunal considered the medical standard that an applicant have no established medical history or clinical diagnosis of drug dependence or use of illicit drugs that is likely to interfere with the safe exercise of, privilege or performance of duties under the licence the person has applied for or holds. The Tribunal said (at [60]):
“Even having regard to the object of the Act with which we are concerned and of the medical standards, it seems to us that to adopt the 1% Rule in considering whether Mr Window’s history of drug dependence and use of illicit drugs is likely to have the prescribed effect would be to adopt notions of possibility. None of the authorities in considering ‘likely’ in a range of contexts has gone that far. Having regard to the need to protect public safety while having regard to a person’s entitlement to pursue his or her ambitions, we consider that the word ‘likely’ means ‘a substantial or real and not remote chance’. That is not a matter which can be assessed on statistical likelihood and certainly does not mean ‘more likely than not’, ‘odds on’ or ‘more than 50% chance of a thing happening’. To adopt those latter three meanings would, in our view, be to place too little weight on the protection of public safety and too much on an individual’s entitlements.”
ISSUES FOR THE TRIBUNAL
The issues for determination by the Tribunal are as follows:
(a) did the Applicant suffer a TIA in November 2012?;
(b) does the Applicant meet the medical standard in Table 67.155?;
(c) if not, whether the degree by which the Applicant fails to meet the medical standard is likely to pose a risk to the safety of air navigation?; and
(d) if such a risk is posed, can the risk be sufficiently mitigated or ameliorated by the imposition of conditions rather than declining to issue a medical certificate?
CONSIDERATION
Introduction
Apart from the key issues for determination, the Applicant raised in his Closing Statement (CS) a preliminary contention which needs to be addressed.
The Applicant drew the Tribunal’s attention to the Criteria for medical standard 2, and, in particular, Item 2.7 – Nervous system. Item 2.7(a) refers to “a safety relevant disease of the nervous system”, and the Applicant contends (CS p. 2) that a TIA is an “episode”, “event” or “attack” rather than a “disease” as Item 2.7(a) specifies.
Leaving aside the previous Tribunal determinations which have proceeded on the undisputed basis that a TIA (or a stroke) is a manifestation of a disease of the nervous system (see, for example, Collins and Civil Aviation Safety Authority [2017] AATA 2564 (Collins) at [43]), nervous system diseases, or neurological disorders, are accepted to be a class of medical conditions affecting the nervous system. Various medical textbooks suggest that over 600 different conditions fall within the concept of nervous system disease. Included within those conditions are those with a vascular (including cerebrovascular) origin.
A disease can manifest itself in many ways, including by the occurrence of episodic events. For example, seizure disorders, such as epilepsy, whilst recognised as a disease usually manifest themselves in “events” or “attacks”.
In short, this submission does not advance the Applicant’s case and the Tribunal is unaware of any Tribunal or Court decision which in this or any other context has cast doubt on the proposition that a disease of the nervous system includes conditions with a vascular origin.
Did the Applicant suffer a TIA in November 2012?
The Respondent submits (RS para 3) that the Tribunal should be comfortably satisfied on the evidence presented that the Applicant suffered an episode of TIA on 21 November 2012.
Amongst other matters, the Respondent relies upon the statement of Dr Peter Clem (Exhibit 4) and his oral evidence. Dr Clem, who has held senior medical positions in the Respondent since 2012, provided evidence supportive of the conclusions reached by Professor Somerville. However, having regard to Dr Clem’s role within the Respondent and his history in this matter, the Tribunal has not placed weight on his conclusions whether the Applicant suffered a TIA, preferring to rely on the independent medical evidence of persons not employed (or previously employed) by the Respondent.
It is not disputed that the Applicant was admitted to the Calvary Hospital on 21 November 2012 and remained a patient at that institution for approximately 36 hours.
The Applicant contends (CS pp. 3- 4) that it has not been proven, established or confirmed that the index event of more than 5 years ago was in fact a TIA. In support of this contention the Applicant made the following submission:
“From the outset (my discharge statement from Calvary Hospital following an exhaustive range of clinical tests), the diagnosis was uncertain: “TIA ?” [T-docs p. 65]. The referral note for MRI examination similarly contained the same description “TIA?” [T-docs p. 69] or, as Dr Fitzgerald characterizes it “Possible TIA in 2012” [T-docs p. 168]. Nor was the hospital’s uncertainty particularly surprising. The history of diagnosis of this neurologic event or episode is endemically marked by doubt, with some medical research papers putting the incidence of mistaken or false diagnosis as high as 60%”.
The Applicant then cited three published articles in support of this proposition, and proceeded:
“On questioning, Prof Somerville acknowledged that, while not resiling from his 5-year post-factum opinion, he had not read any of those studies which had been brought to his attention in my Statement of Facts and Contentions of 21 Nov 2017.
In my own case, the clinical evidence – the objective medical record from those extensive tests – reads as follows
-Chest X-Ray: no evidence of enlarged heart or blood vessel
-CT Brain: no evidence of TIA or ischaemic infarct
-Carotid Doppler : (ultrasound) no evidence of atherosclerosis or valvular heart disease
-MRI Brain (diffusion weighted imaging – DWI) No evidence of recent infarction
-Echocardiogram: no evidence of pathological heart sounds and heart size
-Electrocardiogram (72 hs Holter): no evidence of Atrial Fibrillation
Plus
-a long history of medical reports relating to the alleged co-morbidities in CASA’s reports (including blood pressure and blood lipids) and three aviation medical examinations since 2013 all of which demonstrate that my health has been good to excellent.”
As the Applicant points out, Professor Somerville did not resile from his written opinion when he gave testimony on 22 February 2018. The Tribunal had the advantage of listening to the oral evidence of Professor Somerville, and he presented as a thoroughly professional and objective witness who was neither dogmatic or evasive in answering questions. In short, he presented as a witness of credit.
First, Professor Somerville said that most doctors refer to a TIA as a mini-stroke. The symptoms for a TIA usually resolve in 24 hours from the index event, whereas the symptoms of a stroke can last for more than 20 years. If the symptoms dissipate within 24 hours, there is usually no brain damage.
When asked if he remained of the opinion that a TIA was the most likely diagnosis of the index event, Professor Somerville replied in the affirmative and said that it was far less likely that the index event was caused by a compression of the nerves as distinct from a TIA. When asked why he was of that opinion, he said that compression of a nerve can cause pins and needles, but that only lasted for a matter of minutes, and it would not usually cause muscle weakness, and if it did, such weakness would resolve within a few hours. In the Applicant’s case the symptoms lasted for a much longer period of time.
A close reading of the medical evidence presented leads to a finding, on the balance of probabilities, that the index event in 2012 was a TIA.
With the exception of Dr Malhotra, all of the other medical experts, explicitly or implicitly, have proceeded on the assumption that the Applicant suffered from a TIA in November 2012.
Dr Pitcher, when writing to Dr Gawarikar on 30 January 2013, said: “I wonder if you could help by forwarding his holter monitor report, the possible reason for his TIA (? Hypertension)…” – Exhibit 1 T12 p. 77.
Dr Andrews, in his report of 4 March 2013, opined that the “cause of his TIA is not clear but we assume that is probably embolic off the vessel wall which is the commonest cause” – Exhibit 1 T14 p. 89.
Dr Gawarikar, in his report of 26 March 2013, diagnosed the Applicant with, inter alia, “Right hemisphere TIA” – Exhibit 1 T16 p. 92.
Dr Pitcher opined in his Medical Questionnaire and Examination form dated 14 November 2014 – Exhibit 1 T25 p. 121:
“Dr Reubel has had no recurrence of a cerebrovascular accident or transient ischaemic attack since 27/11/12.”
Dr Andrews again examined the Applicant on 23 March 2016 and noted in his report of the same date – Exhibit 1 T33 p. 138:
“This gentleman I have seen previously following a mini-stroke from which he has made a recovery.”
In addition there are the reports of Dr Fitzgerald and Professor Somerville.
While the Tribunal has not placed weight on Dr Fitzgerald’s report for the reasons previously expressed, it has been cited by the Applicant in support of his contention. On this basis, the Tribunal will deal with Dr Fitzgerald’s findings. Dr Fitzgerald was clearly of the opinion that the Applicant had suffered from a “transient ischaemic attack of uncertain or undetermined cause” – Exhibit 1 T45 p. 165. Although he subsequently says “Possible TIA in 2012”, his discussion of whether a Pilot’s licence should be granted and his reference to the van Wijk article, is predicated on a diagnosis of (at least) a TIA. Indeed, he makes reference to risk factors of a “future stroke” – Exhibit 1 T45 pp. 168 – 169. In short, there is no support in Dr Fitzgerald’s report for the alternative diagnosis of a pinched nerve being the cause of the index event.
The only medical expert to suggest that the index event was possibly not caused by a TIA is Dr Malhotra. I leave to one side Dr Pitcher’s subsequent report of 8 April 2016 (Exhibit 1 T38 p. 144) which echoes Dr Malhotra and which is inconsistent with his previous reports.
Dr Malhotra’s diagnosis is guarded. He opined in his report of 1 April 2016 – Exhibit 1 T36 p. 141:
“I am not sure whether Gerhard had a TIA or just compression of the sciatic nerve from prolonged sitting in one position.”
In short, at its highest, all that Dr Malhotra opined is that compression of the sciatic nerve was a possible diagnosis, but he did not discount a TIA.
The Tribunal acknowledges, as the Applicant submitted, that there is a possibility that an event labelled as a TIA may be a misdiagnosis, and further acknowledges from the learned medical journals he cited, that such misdiagnosis is not a remote possibility.
However, the sheer weight of medical evidence before the Tribunal leads to the conclusion that the index event was caused by a TIA. The Tribunal accepts the analysis of Professor Somerville in his report of 17 February 2017 that compression of the sciatic nerve is an unlikely explanation of the cause of the index event.
The MRI of 28 November 2012 disclosed multiple “tiny foci of white matter signal throughout the brain” which “most likely represent early chronic white matter ischaemic change” – Exhibit 1 T9 p. 69. This indicates, as Professor Somerville observed: “changes in the small blood vessels within the brain, usually due to elevated blood pressure” – Exhibit 2 p. 5.
Finally, the medical documents admitted into evidence highlight that the Applicant has a history of high blood pressure.
In the Medical Questionnaire and Examination form of 27 January 2011, Dr Pitcher diagnosed the Applicant with high blood pressure, and in the additional information section, noted that he suffered from “hypertension” – Exhibit 1 T4 pp. 52, 58. This was despite a low blood pressure reading on that day of 128/85.
Again, Dr Pitcher noted in the Medical Questionnaire and Examination form of 14 November 2014 that the Applicant suffered from high blood pressure, despite another low reading of 123/78 – Exhibit 1 T25 pp. 115, 118.
Of interest is the report of Dr Andrews of 23 March 2016. When he examined the Applicant on that day his blood pressure was 190/100, which he explained as a factor of “white-coat syndrome” – Exhibit 1 T33 p. 138.
Whether the Applicant’s high blood pressure is due to “white-coat syndrome” or not, the fact is that he suffers from bouts of high blood pressure caused, perhaps, by stress. Stress, itself, can be activated by a plethora of different situations. It is not possible, or appropriate, for this Tribunal to opine about the triggers for the activation of high blood pressure in persons susceptible to this syndrome (presuming that the Applicant is so susceptible). All that the Tribunal has to be satisfied is that, amongst other things, the Applicant has a history of variable high blood pressure.
Consequently, and discounting matters that are not relevant, the Tribunal finds that, on the balance of probabilities, the index event was a TIA.
Does the Applicant meet the Class 2 medical standard for the issue of an unrestricted medical certificate?
As previously pointed out, the Tribunal is required to focus on the requirements of Items 2.1 and 2.7 of the criteria for medical standard 2 as set out in Table 67.155 of the Regulations.
It will be noted that Item 2.7 refers to an “established medical history”. This term is not defined in the Regulations, however guidance is provided by the Full Federal Court in Neal v Secretary, Department of Transport (1980) 3 ALD 97 which considered the same phrase in the Air Navigation Orders made under the Air Navigation Act 1922 (Cth).
Franki J made the following observations (at 101):
“The main argument presented by the applicant was that the single psychotic incident in 1967 did not constitute an established medical history of psychosis. In my opinion the expression ‘established medical history’ means no more than a medical history which is established on the balance of probabilities and that a series of incidents is not necessary to constitute an established medical history of psychosis.”
Lockhart J was of the same view (at 104):
“In my opinion the expression ‘established medical history’ means a medical history which is proved, established or confirmed. There is no necessity for a number or series of episodes or events to occur before there is an ‘established medical history’.”
It follows, then, that as the Applicant has had one TIA, he has an established medical history of a safety relevant disease of the nervous system, and does not meet the medical standard in Item 2.7(a) of Table 67.155 – see Collins at [41] – [45].
The extent to which the Applicant poses a risk to the safety of air navigation
The next question is whether the extent by which the medical standard is not met is likely to endanger the safety of air navigation. The Tribunal accepts from the evidence presented that the Applicant’s “medical history” of TIA carries with it an elevated risk of suffering a cerebrovascular event. The question that must be answered, then, is the extent of that risk.
As explained earlier, reg 67.015 provides that a medically significant condition is “safety-relevant” if it “reduces, or is likely to reduce, the ability of someone who has it to exercise a privilege…or perform a duty imposed…by a licence that he or she holds or has applied for.” Further, as explained by the Tribunal in Window, “likely” means a substantial or real and not a remote chance.
Having regard to the catastrophic consequences that could follow if a pilot becomes incapable of navigating his or her aircraft, all risks, no matter how small, must be carefully considered and appropriate remedial action instigated. While risks that are remote and unlikely to eventuate should be weighed accordingly, the Act and Regulations impose on the Respondent a high duty of care to maintain air safety so that the Australian community can be confident that the highest levels of probity are being undertaken – see Hall and Civil Aviation Safety Authority [2004] AATA 21 at [45].
As Deputy President Molloy highlighted in Goldstein and Civil Aviation Safety Authority [2016] AATA 57 at [38], even a mild event producing pain and discomfort could distract a pilot from the critical task of flying. Such a painful distraction at such a critical time could have catastrophic consequences.
The Regulations do not specifically prescribe any particular level of risk, however there is a generally accepted guideline in international aviation medicine known as the 1% rule. This rule was helpfully explained by the Tribunal in Collins at [72] – [78].
Dr Clem explained that in an aeromedical context, risk is referred to an “absolute risk”, which is the risk of developing an incapacitating condition over a period of time, rather than a “relative risk” which is used to compared the risk in two different groups of people – Exhibit 4 para 16.
Dr Clem also explained that the risk of incapacitation is often expressed as an annual percentage. He gave as an example the pilot incapacitation risk of 1% per annum which means that if there are 100 pilots with an identical condition, one of them would be predicted to become incapacitated during the next 12 months while 99 would not – Exhibit 4 para 17.
The Tribunal pointed out in Collins that a 1% annualised risk of incapacitation is generally regarded as the acceptable level of risk for pilots flying commercial aircraft. The rule is set out and explained in the International Civil Aviation Organisation Manual of Civil Aviation Medicine. The Organisation is a United Nations agency established in 1944 pursuant to the Convention on International Civil Aviation (the Chicago Convention), of which Australia is a Member State.
The importance of this is made clear by s 11 of the Act which requires the Respondent to perform its functions “in a manner consistent with the obligations of Australia under the Chicago Convention…”.
Dr Clem highlighted in his statement that the Respondent uses the Standards and Recommended Practices for medical fitness for licence holders as stated in Chapter 6 of Annex 1 to the Chicago Convention – Exhibit 4 para 9.
The Tribunal also explained in Collins that the Respondent allows for a 2% annualised risk of incapacitation for class 2 licences because of the different profile of flying.
The Respondent informed the Tribunal (RS paras 12 – 13) that the 1% and 2% rules are (as explained by Dr Clem) premised on absolute risk without further reduction for variables such as flight hours per annum and the like. The Respondent submitted:
“Viewed another way, apart from the unreliability and inappropriate application of factors to the risk calculations, the figures ultimately arrived at could not be correct as they show that under no circumstances would the Applicant, or any other person who experienced a TIA or cerebrovascular event, exceed the 1% or 2% thresholds. All that this reveals is that judicious manipulation of statistical variables can be used to make even substantial risks appear less significant when considered in a purely theoretical mathematical framework. Of course, the conduct of aviation activities such as piloting an aircraft , does not take place in a mathematical framework. Understood in that context the figures are simply unreliable and of no assistance to the Tribunal.”
The Respondent was alluding to the submissions made by the Applicant. The Applicant contends that the risk of his having an incapacitating event during flight is not real or substantial, but remote – CS p. 4. The Applicant relies on the evidence of Mr Muller.
Mr Muller, who is an Accredited Statistician, prepared a paper entitled “Risk Calculations of Recurrence of TIA” which is aimed at calculating the risk of a private pilot suffering a recurrence of TIA while actually flying.
In the section headed “Assumptions”, the following information is provided:
“The calculations below assume there are three components to a calculation of risk of suffering a TIA recurrence while flying:
· Probability that the TIA was originally a correct diagnosis
· Probability that second TIA or stroke will occur in a given year
· The amount of flying that is undertaken in a given year
1. Dr Reubel informed me that up to 60% of events diagnosed as TIAs may not be TIAs. Therefore a range of probabilities between 0.4 and 1.0 of correct diagnosis can be assumed.
2. Dr Reubel has also reported to me that a publication frequently quoted by CASA (Long-term survival and vascular event risk after transient ischaemic attack or minor ischaemic stroke: a cohort study. I van Wijk et al. The Lancet 18 June 2005; 365, No 9466, p2098-2104) gives an annual risk of 2% to 4% for a second TIA or stroke to occur. Nevertheless, I shall add as a safety margin an annual recurrence risk of 5% and 6% to the calculations. Therefore a range of probabilities between 0.02 and 0.06 will be assumed. It should be noted that there may be age-dependence in the recurrence probability, with older people more likely to suffer a recurrence. However, I do not have data on how age would change probabilities.
3. The risk of a TIA or stroke will increase as flying hours increase. There are 8760 hours per year…I will assume 50 hours flying time per year, which is maximum hours Dr Reubel has flown in any given year and which he has told me would accept as a restriction by CASA)…”
Mr Muller then outlined his probability calculations and included a Table with probability calculations based on various scenarios. His conclusion was as follows:
“It is clear that all the probabilities are extremely low, with the highest one, 0.00343, representing approximately a 1 in 300 chance that a TIA or stroke would occur while flying.”
It became clear during Mr Muller’s evidence that his statistical analysis was made without any significant knowledge of how risk was assessed by the Respondent, or the development and implementation of the 1% and 2% rules in international aviation medicine.
It is also clear from his paper, and he has proceeded on the assumption that the Applicant may not have suffered a TIA in 2012.
Further, his calculations do not include the critical impact of the increased risk of TIA with advancing years.
Finally, and most importantly, Mr Muller’s calculations are predicated on the risk of a TIA or stroke in a 50 hour component of a 8760 hour year. Such an approach would mean, almost inevitably, that almost all persons would be characterised of having a low risk of a further medical event.
The final aspect of Mr Muller’s analysis was commented on by Dr Clem in his statement as follows – Exhibit 4 para 33:
“b. Mr Muller has applied a mathematical adjustment to the acceptable risk tolerances based on the number of hours in a year and the average number of hours flown by the Applicant in an average year. This approach fails to fully understand the development and subsequent application of objective risk assessment in provision of flexibility provided for in the CASRs. CASA does not accept that it is appropriate to raise the acceptable risk tolerances based on these assumptions and mathematical modification.”
It should be noted that the Tribunal found Mr Muller a credible and sound witness, and his calculations are not questioned from a purely mathematical perspective. Nonetheless some of the key assumptions underlying his analysis are, as noted above, questionable. Consequently, as a tool to assist the Tribunal in assessing risk in the context of the aviation medical regulatory regime in question, Mr Muller’s calculations are not of assistance.
Both the Tribunal in Collins and the Tribunal is this matter were referred by the Respondent to various peer reviewed medical studies that have assessed the risk of recurrence over extended periods of time from an initial TIA. The principal study relied upon is the van Wijk article.
Because the van Wijk study played such a central role in the hearing and follow-up submissions, it is necessary to deal with it at some length.
The study assessed the survival status and occurrence of vascular events in 2473 participants of a Dutch TIA trial. Patients from 24 hospitals were assessed, and follow-up was completed in 2447 patients (99%).
After a mean follow-up of 10.1 years, 1489 (60%) of patients had died and 1336 (54%) had at least one vascular event.
The Introduction to the article is set out below (p. 2098):
“Although worldwide fatality rates from cerebrovascular disease have fallen, stroke remains one of the most serious neurological problems, which leaves most patients with chronic disability. Secondary stroke prevention is standard practice in patients with a transient ischaemic attack (TIA) or minor ischaemic stroke, but many of these individuals have a recurrent stroke or other vascular complications.
In clinical studies so far, the follow-up of patients with TIA or stroke has lasted no longer than 3-5 years for the assessment of the incidence of recurrent stroke, myocardial infarction, and vascular death. 5-year cumulative risk of a recurrent stroke was 22.5%; major determinants of recurrence were advanced age, haemorrhagic index stroke, and diabetes mellitus. In cohorts from clinical trials, the yearly risk of vascular events ranged from 4% to 11% if the presumed cause of the cerebral ischaemia was arterial disease. The corresponding estimate for population-based studies is 9% per year. Observational studies report a wide range of incidence rates for cerebral ischaemia of miscellaneous severity (TIA vs stroke) and type (arterial vs cardiac), with various outcome measures and lengths of follow-up (most to a mean of 5 years). Much of the variation between studies on the prognosis of patients after TIA is due to the fact that many did not fulfil six important principles in their methods: description of diagnostic criteria, description of outcome events, study of an inception cohort, description of outcome surveillance, report and analysis of censored patients, and multivariate analysis for predictive variables.
Only a few hospital-based studies have had follow-up periods of 10 years or more after stroke. Apart from one study, the inclusion period of these studies was between 1977 and 1986, during which secondary prevention was not routinely prescribed. The numbers of participants in most studies were small (n+178-339) and none of the studies fulfilled all six criteria mentioned above. The few community-based studies with extended follow-up focused on mortality only and did not study prognostic factors. We aimed to assess long-term risk of death and vascular events in patients with TIA or minor stroke of arterial origin. We also studied any changes in risk over time and identified any independent predictors of mortality and vascular events.”
The follow results were noted (2100-2101):
“The mean age at study entry was 65 years…
Mean follow-up was 10.1 years…Since the DTT began, 1489 patients had died; cause was vascular death in 1076 (72%). Cumulative risk of death was 3.4%...at 1 year, 19.4%...at 5 years, and 42.7%...at 10 years…10-year risk of death for patients who presented at baseline with stroke was 46.6%...and 34.1%...for those with TIA…
10-year risk of vascular events for patients with minor stroke was 47.8%...and 35.8% for those with TIA…
Our study shows that, roughly 10 years after a presentation of TIA or minor ischaemic stroke, about 60% of patients had died and 54% had experienced at least one new vascular event. Event-free survival after 10 years was 48%. The risk of a vascular event was highest shortly after the ischaemic event, reached its lowest point at about 3 years, and gradually rose afterwards. The same pattern was recorded for the risk of stroke during the first 3 years, whereas the risk for mortality gradually rose throughout the study.”
Figure 2 contains a Chart which illustrates the development of yearly risks over a ten year period. The Chart suggests that the recurrent risk of stroke is 5% initially, falling by year 3 to 2% and remaining stable over the following eight years. However, the recurrent risk of a vascular event, including a non-fatal stroke, non-fatal myocardial infarction, cardiovascular and cerebrovascular death is initially 7%, reducing to 4% after three years, but steadily rising thereafter until reaching 7% again by year 10.
The Respondent submits (RS para 16) that these risk rates are well in excess of either the 1% or 2% rates applicable to aviation medical certification.
In Collins the Tribunal noted (at [107]) that an assessment of risk must be made somehow, and concluded that the body of evidence from the randomised trial studies before it (including van Wijk) provided the best information available to assess the applicant’s risk.
The rigid application of percentages in ascertaining risk is inherently problematic. The evidence used to develop percentage of risk is usually capable of producing degrees of error. So too, in this matter, the van Wijk study while providing a solid basis for calculating risk, is not conclusive.
Dr Clem in his statement made the following observation, which the Tribunal accepts – Exhibit 4 para 23:
“It needs to be stressed that while numerical criteria are of assistance in providing a level of consistency, because of the many variables in each different case, the ultimate decision is made on the basis of a judgment as to whether there is a real and substantial (and not trivial) risk to the safety of air navigation”.
This illustrates why the approach to ascertaining risks expounded in Window provides a sound basis for reaching a conclusion. As the Tribunal pointed out in Mulholland and Civil Aviation Safety Authority [2007] AATA 1952, the regulatory regime does not refer to the level of risk, simply to a safety relevant condition that produces a risk of incapacitation. Senior Member Cunningham and Member Fice then said (at [63]):
“The degree or level of risk is not a criterion prescribed by the legislation. Caution was expressed by the Tribunal when considering the value of statistics with respect to the risk of safety and medical cases.”
Here, the evidence leads to the conclusion that the Applicant suffered a TIA more than five years ago and is now aged more than 60 years. The van Wijk study suggests that the Applicant is now in an age and time cohort following the index event, which places him at greater risk of a vascular event.
Dr Somerville opined that although there is some variation in risk levels following the index event “this variation is small beyond the 4 year mark and is of the order of 6-7% per year for vascular events” – Exhibit 2 p. 3.
Looked at in these stark terms, it could not be said, as a matter of common sense, that the Applicant only has a remote chance of having a stroke or vascular event in the next five years. On the contrary, the van Wijk study suggests that there is a real risk that he may do so.
In reaching this conclusion, I am mindful that overall the Applicant is a fit man who leads a healthy lifestyle. In reaching a conclusion as to medical risk the Tribunal is simply making a finding on the evidence presented of the likelihood of the threat to the safety to air navigation posed by the grant of an unconditional medical certificate.
Can a medical certificate be issued with appropriate conditions?
The Respondent submitted (RS para 19) that it had given consideration to whether conditions could be imposed to reduce the potential risk to an acceptable level. After due consideration the Respondent concluded that the only appropriate condition to reduce the risk involved was the imposition of a requirement that the Applicant could only fly if accompanied with a safety pilot.
The Respondent made the following submissions (RS paras 20 - 23):
“20. The safety pilot condition being the only condition which ensured that in the event of an inflight cerebrovascular event that there was another qualified pilot onboard the aircraft capable of recovering the situation and landing the aircraft. Although the Applicant challenges the safety pilot condition and has continued to advance other possible conditions in substitution, the Respondent submits that the Tribunal would not be satisfied that the other proposed conditions would adequately manage the risks.
21. For example, limiting the number of flying hours flown per annum and the areas of flight does not address the fundamental requirement to ensure the Applicant’s own safety in addition to that of other air users and third parties on the ground and their property. Such an approach gives the illusion that the occurrence of medical episodes such as stroke is liable to control in a way which will prevent any such incident from taking place while the applicant is at the controls of an aircraft in flight. However, human physiology does not conform to such theoretical statistical constructs and for that reason, this approach should be rejected…
22. A further consideration against removal of the current safety pilot condition is that the Applicant’s evidence indicates that compliance with the condition is more an issue of convenience than inability to comply. The Applicant confirmed he has been able to engage in some flying with a safety pilot. Further, he seeks the removal of the condition as he prefers to be able to fly without a safety pilot. When questioned as to the type of flying he engages in, he admitted that he could conduct ‘fly-aways’ where he and other pilots and friends would travel to a location. The Applicant admitted that this generally involved more than one pilot (including him) being onboard the aircraft.
23. Contrary to the Applicant’s evidence, the Tribunal would be satisfied that the Applicant could readily ask of those pilots to act as his safety pilot so long as that pilot is legally qualified to fly the relevant aircraft. No payment need be involved in such an arrangement (also contrary to the Applicant’s evidence). No other identified basis for removal of the safety pilot condition was identified as the Applicant admitted that some functions he previously performed on behalf of the Canberra Aero Club are now performed by other club members, such as ferry flights and taking aircraft for maintenance.”
The Applicant testified that on most occasions he flew aircraft from Canberra to southern New South Wales coastal areas (e.g. Bega) and from Canberra to Cowra. On occasions he has flown longer distances, including one trip from Canberra to Kangaroo Island and another with his wife to Birdsville to observe Lake Eyre when it was in flood. The Applicant also detailed a trip he undertook from Canberra to Wagga Wagga for aircraft maintenance.
The Applicant contended that a sensible compromise would be to impose the following restrictions on his capacity to fly – CS p. 7:
(a)Flying to a maximum of 50 hours per year when flying without a safety pilot;
(b)Taking a maximum of three passengers when flying without a safety pilot; and
(c)Flying aircraft to a maximum Take-Off Weight of 1500 kg when flying without a safety pilot.
Dr Clem explained in his statement the risk management approached adopted by officers of the Respondent – Exhibit 4 para 13:
“In making a medical certification decision, CASA Medical Officers consider the overall risk that the Applicant’s medical condition presents to aviation safety and the utility and reliability of risk mitigation efforts. This includes a consideration of the individual’s age, experience, type of flying, currency, extent of flying, the medical condition, the treatment, possible side effects of treatment and a range of other similar and interrelated issues.”
The evidence discloses that the Applicant does not engage in very long periods of flying, and when he does fly it is usually to locations in rural or regional Australia. Further, when he engages in flying activities it is of a non-commercial nature with relatively few persons on board the aircraft. As previously highlighted, the Applicant is a professional person who lives a healthy lifestyle. The Tribunal found the Applicant to be a man of very good character who presented throughout the hearing as an honest and credible witness and advocate.
The evidence, however, also discloses that the Applicant suffered a TIA in 2012 and now is in excess of 60 years of age. The risk, or likelihood, of him suffering a further medical condition while in control of an aircraft, is increasing with each year.
As part of the weighing exercise, the Tribunal is required to factor in and carefully assess the considerations outlined by Dr Clem above. The Tribunal is mindful that s 9A(1) of the Act requires this assessment be viewed through a prism which places a primacy on the safety of air navigation.
It is undisputed that medical evidence is imperfect and provides only a guide to decision making. The imperfection of medical evidence does not, however, default to a decision to ignore it; rather it requires a decision-maker to give it the weight that is appropriate in each case.
In this matter the overwhelming weight of medical evidence points to the Applicant suffering a TIA in 2012. He has been on medication since, and is in ostensibly good health. Nonetheless, it also suggests that he is predisposed to a further medical event at some future time, and this risk is heightened by his age and the effluxion of time since the index event.
The Tribunal has given considerable attention to the appropriate way of dealing with this situation. It is not, by any means, unaware of the inconvenience and cost that the maintenance of a safety pilot condition will impose on the Applicant.
The risk of the Applicant suffering a stroke or vascular event in the next five years is substantial and real, and not a remote chance. In Collins (at [120] – [122]) the Tribunal outlined at length the physical consequences of a stroke on the pilot of an aircraft. Even if the Applicant did not suffer a stroke but a far less serious vascular event, his ability to fly an aircraft would be severely impaired. Even a minor deterioration in a pilot’s physical or mental health could result in catastrophic consequences.
In these circumstances it is necessary to weigh the cost and inconvenience of imposing a Safety Pilot Condition against the risk to aviation safety if the Applicant suffered a recurrent medical event.
During the Applicant’s testimony four key matters were disclosed.
First, the Applicant pilots aircraft for pleasure and obtains no monetary reward of any kind for this activity. In short, he is a recreational pilot and any restrictions or imposition on his ability to fly a plane will not adversely impact on his capacity to earn a living or otherwise negatively impact on his general way of life.
Second, insofar as he assisted his Aero Club by, inter alia, flying a plane to Wagga Wagga for servicing (as there are no servicing facilities in Canberra), other member pilots have subsequently “filled the gap” since restrictions were placed on his flying capacity. Consequently, the imposition of a Safety Pilot Condition has not, and presumably will not, result in the Aero Club being substantially disadvantaged.
Third, the Applicant conceded that although paying for a Safety Pilot was a severe imposition on him, other members of the Aero Club could fulfil that role at no cost to him. In short, the Safety Pilot Condition would not necessarily impose a prohibitive cost impost on the Applicant’s capacity to fly.
Finally, it became clear during Mr Carter’s cross-examination of the Applicant, that he was under a misunderstanding that a Safety Pilot was not permitted to log flying hours for such a flight. Mr Carter pointed out during the hearing, and this was re-inforced in the Respondent’s Submissions of 8 March 2018, that a co-pilot is legally permitted to log flying hours for such flights. In short, the evidence disclosed that the Applicant’s Aero Club fellow-members could co-pilot for him at no cost and with the benefit of logging flying hours for this activity.
Factoring in all these considerations, the risk of the Applicant suffering a further medical event far outweighs his personal inconvenience. The imposition of a Safety Pilot Condition is not only fair and appropriate for the broader community, but is also in the best interests of the Applicant.
DECISION
The decision under review is affirmed.
| 1. I certify that the preceding 175 (one hundred and seventy-five) paragraphs are a true copy of the reasons for the decision herein of Deputy President John Sosso 2. |
.......................................................................
Associate
Dated: 31 May 2018
| Date(s) of hearing: | 22 February 2018 |
| Applicant: | In person |
| Representative for the Respondent: | Mr A Carter Litigation, Investigations and Enforcement Branch CASA |
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