Cessna T303 Series Aeroplanes
AD/CESSNA 303/6
Amdt 1
Applicability: All T303 series. Requirement: Part 1:
Seat Adjustment Mechanism 9/88
- Measure each hole in the seat track(s) for excessive wear. If the wear dimension across any hole exceeds 10.67mm (0.42") to a maximum depth of 3.81mm (0.15"), replace the seat track prior to further flight.
Section of seat track showing hole wear.
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.
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.
COMMONWEALTH OF AUSTRALIA (Civil Aviation Regulations 1998), PART 39 - 105 CIVIL AVIATION SAFETY AUTHORITY
SCHEDULE OF AIRWORTHINESS DIRECTIVES
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 limitation 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 255mm (10") 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
a. 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
a. iii. Thereafter at each inspection for Maintenance Release issue closest to a 100 hour inspection interval or every 12 months, whichever is earlier. 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 Civil Aviation Regulations 1998, under Part 39 - 105 of the Civil Aviation Safety Authority, introduce the Airworthiness Directives concerning Cessna T303 Series Aeroplanes, specifically addressing AD/CESSNA 303/6 Amendment 1. This legislative instrument was enacted to address the problem of seat adjustment mechanism failures, which have historically resulted in accidents. The objective of this amendment is to ensure the continued airworthiness of T303 series aeroplanes by requiring detailed inspections and maintenance of the seat adjustment mechanisms, including the replacement of worn parts and modification of seat travel limits. The directive outlines specific requirements for inspecting and maintaining seat tracks, rollers, pins, and housing, with the aim of preventing mechanical failures that could compromise safety during flight. Compliance with these directives is mandatory and must be carried out at specified intervals to maintain the safety standards set forth by the Civil Aviation Safety Authority.
Scope and Application
This legislative instrument applies to all T303 series Cessna aeroplanes and outlines specific maintenance requirements and compliance schedules for the seat adjustment mechanisms of these aircraft. It is issued under the authority of the Civil Aviation Regulations 1998 and pertains to the Commonwealth of Australia, ensuring that the standards set forth are consistently applied across the nation. The Act mandates thorough inspections and maintenance of the seat tracks, rollers, washers, and associated components to prevent failures that could lead to accidents. Any non-compliance with the specified requirements could result in the grounding of the aircraft until the necessary repairs or replacements are completed. The Act does not explicitly state any exclusions, but it does allow for temporary schemes to be approved by the Secretary, which can offer alternative compliance measures under specific conditions, such as when replacement parts are in high demand.
Key Provisions
The AD/CESSNA 303/6 Amendment 1, part of the Civil Aviation Safety Authority regulations, outlines specific requirements for maintaining the seat adjustment mechanisms in T303 series aeroplanes. In Part 1, the AD mandates a series of checks and actions to ensure the integrity and proper functioning of the seat adjustment mechanism (sections (a)-(g)). For example, section (a) requires the measurement of seat track holes for wear, with replacement necessary if the wear exceeds specified limits. Similarly, sections (b)-(g) detail inspections for debris, pin engagement, roller condition, and spring functionality, among other checks, with specific corrective actions prescribed for identified issues. Part 2 of the AD addresses the modification of the seat adjustment mechanism to limit seat travel to specific distances (255mm or 153mm) and provides a compliance schedule based on the aircraft's service hours.
The AD imposes several obligations on the parties involved, primarily focusing on the maintenance and inspection of the seat adjustment mechanisms. Operators and maintenance personnel must adhere to the specified inspection intervals and corrective actions to ensure compliance with the AD. This includes performing detailed inspections as outlined in Part 1, such as measuring hole wear and ensuring proper pin engagement, and modifying the seat adjustment mechanisms as per Part 2. Non-compliance with these requirements could result in the aircraft being deemed unairworthy, thus impacting the operator's ability to fly the aircraft until the required maintenance is completed.
Failure to comply with the AD/CESSNA 303/6 Amendment 1 could result in significant consequences. Civil Aviation Safety Authority regulations may deem the aircraft non-airworthy if the required inspections and maintenance are not performed as specified. This could lead to enforcement actions, including potential fines or other penalties. The exact penalties would depend on the specific breaches and the jurisdiction's regulations at the time, but the overarching consequence is the inability to operate the aircraft until compliance is achieved. Operators must ensure that all mandated checks and modifications are completed in a timely manner to avoid these adverse outcomes.