Cessna 150, F150, 152 & F152 Series Aeroplanes
AD/CESSNA 150/40
Amdt 1
Seat Adjustment Mechanism 9/88
Applicability: Model Serial Number
150A, 150B, 150C, 150D, 150E, 150F, 50G, 150H,
150J, 150K, 150L, 150M
15059019 to 15079405
A150K, A150L, A150M A1500001 to A1500734
152, A152 All
F150F,F150G, F150H, F150J, F150K, F150L, F150M, FA150K, FA150L, FRA150L, FRA150M
All
FA152, F152 All
Requirement: Part 1:
(a) Measure each hole in the seat track(s) for excessive wear. If the wear dimension across any hole exceeds 10.67mm (0.42") to maximum depth of 3.81mm (0.15"), replace the seat track prior to further flight.
SECTION OF SEAT TRACK SHOWING HOLE WEAR - Figure 1.
(b) Visually inspect the seat rail holes for dirt and any debris which may preclude engagement of the seat pin(s). Remove any such material prior to further flight.
COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
(c) Lift up on the forward edge of each seat to eliminate all vertical play. With the seat in this position, measure the depth of engagement of each seat pin. If the engagement of any pin is less than 3.81mm (0.15") (see Figure 2), replace or repair necessary components to achieve a seat pin engagement of 3.81mm (0.15") or greater prior to further flight.
Figure 2
(d) Visually inspect seat rollers for flat spots. Ensure all rollers and washers turn freely on their axle bolts (or bushings if installed) and move freely on the seat rails. Replace rollers having flat spots and any worn washers prior to further flight. If there is any binding between the bores of the rollers, washers, and axle bolts (or bushings if installed), remove, clean, and reinstall these parts prior to further flight.
Note: Do not lubricate rollers, washers, axle bolts or bushings as the lubrication will attract dust and other particles which can cause binding.
(e) Measure the wall thickness of the roller housing and the tang (see Figure 2). If the tang thickness has worn to less than 1/2 the housing thickness, replace the roller housing prior to further flight.
(f) Check the spring(s) that keep the lock pin(s) in position in the track holes for positive engagement action. Replace any spring which does not provide positive engagement prior to further flight.
(g) Visually inspect the seat tracks for cracks in accordance with Cessna SIL SE83-6, dated 11 March 1983. Any limitations imposed as a result of seat track cracking shall be endorsed on the Maintenance Release. Replace any seat rail exceeding the crack criteria as specified in SE83-6 with a serviceable rail prior to further flight.
Part 2:
In accordance with temporary schemes approved by the Secretary, modify seat adjustment mechanisms to permanently limit seat travel to either 205mm (8") or to 153mm (6") as applicable, aft of the forward stop.
Note: FAA AD 87-20-03 R1 refers.
Compliance: A. (i) For aircraft with less than 1000 hours time in service as at 28 January 1988, prior to attaining 1100 hours time in service; or
(ii) For aircraft with more than 1000 hours time in service as at 28 January 1988, at the next inspection for Maintenance Release issue after 28 January 1988; and
(iii) Thereafter at each inspection for Maintenance Release issue.
B. Pending any component replacement necessary to fully comply with Requirement: Part 1, compliance with Requirement: Part 2 is an acceptable alternative until 30 June 1989.
Background: There has been a history of seat adjustment mechanism failure that has resulted in accidents. As there will probably be a high demand for replacement items, Part 2 of the Requirement enables continued flight. Schemes acceptable to the Secretary are available from Regional Offices.
Overview
The Cessna 150, F150, 152 & F152 Series Aeroplanes AD/CESSNA 150/40 Amendment 1, issued in 1988, was enacted to address the issue of seat adjustment mechanism failures in certain Cessna aircraft models. This legislative instrument was created under the authority of the Civil Aviation Regulations 1998, specifically targeting the seat adjustment mechanisms to enhance safety and prevent accidents. The policy objective of this directive is to ensure the airworthiness of the specified Cessna aircraft models by mandating detailed inspections and repairs of the seat adjustment mechanisms, including the seat tracks, rollers, and other related components, in order to maintain safe operational standards. Compliance with these directives is mandatory at specific intervals and conditions, as outlined in the AD, to ensure that the aircraft remain in a safe and airworthy condition.
Scope and Application
The AD/CESSNA 150/40 Amendment 1 applies specifically to the Cessna 150, F150, 152 and F152 series aeroplanes within certain serial number ranges, including both original and amended model serial numbers. This legislation mandates specific maintenance and inspection requirements for the seat adjustment mechanism to ensure the continued airworthiness and safety of these aircraft. The requirements apply to all aircraft operators and maintenance personnel responsible for these models. The legislation's reach is national, as it is issued under the authority of the Civil Aviation Regulations 1998, which govern civil aviation safety across Australia. The regulations mandate compliance with airworthiness directives, including this one, to ensure that aircraft meet the necessary safety standards. The legislation does not specify exclusions or exemptions, implying that all applicable aircraft must comply. Compliance with this airworthiness directive may be extended or modified through subordinate instruments approved by the Secretary, allowing for temporary schemes that provide alternatives to full compliance until specific dates.
Key Provisions
The primary operative sections of the legislation (AD/CESSNA 150/40Amdt 1) mandate specific inspections and maintenance actions for the seat adjustment mechanisms of certain Cessna 150, F150, 152, and F152 series aeroplanes. Section (a) requires the measurement of holes in the seat tracks for wear, with a replacement necessary if the wear exceeds 10.67mm (0.42") to a maximum depth of 3.81mm (0.15"). Section (b) mandates a visual inspection of seat rail holes for dirt and debris, ensuring removal of any such material before further flight. Section (c) involves lifting the forward edge of each seat to eliminate vertical play and measuring the depth of seat pin engagement, requiring repair or replacement of components if engagement is less than 3.81mm (0.15"). Sections (d) and (e) instruct visual inspections of seat rollers and washers for flat spots or binding, along with measurements of the wall thickness of the roller housing and tang, with replacements necessary if conditions are not met. Section (f) requires inspection and replacement of springs in the lock pins if they do not provide positive engagement. Finally, Section (g) calls for a visual inspection of the seat tracks for cracks, with replacements required if criteria are exceeded.
The legislation imposes several obligations on the parties involved. Aircraft owners and operators must ensure that the seat adjustment mechanisms on the specified models are inspected and maintained as per the requirements outlined in Part 1. This includes measuring hole wear, removing dirt and debris, ensuring proper seat pin engagement, inspecting and replacing worn components, and checking the condition of springs and tracks. Aircraft maintenance personnel are required to perform these inspections and maintenance actions to ensure compliance with the regulations. Additionally, the legislation mandates compliance with the modification of seat adjustment mechanisms to limit seat travel, as outlined in Part 2.
Failure to comply with the requirements of this legislation can result in significant consequences. Although the specific civil or criminal penalties are not detailed in the text, non-compliance with airworthiness directives can generally lead to enforcement actions by the Civil Aviation Safety Authority (CASA), including fines, suspension or revocation of airworthiness certificates, and potential criminal charges in cases of serious non-compliance. These penalties are intended to ensure that aircraft are maintained in a safe and airworthy condition, thereby protecting public safety and the integrity of the aviation system.