Cessna 185 Series Aeroplanes
AD/CESSNA 185/43
Amdt 1
Seat Adjustment Mechanism 9/88
Applicability: Model Serial Number
185, 185A, 185B, 185C, 185D, 185E, A185E, A185F
Requirement: Part 1:
All
- 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.
Figure 1.
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
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 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
- 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 AD/CESSNA 185/43 Amendment 1, issued in 1988, is a legislative instrument enacted by the Civil Aviation Safety Authority under the Civil Aviation Act 1988. This instrument was introduced to address safety concerns related to seat adjustment mechanisms in Cessna 185 series aeroplanes, which had a history of failures leading to accidents. The primary objective of this directive is to ensure the continued airworthiness of these aircraft by mandating regular inspections and maintenance of the seat adjustment mechanisms. Compliance with these regulations is crucial for preventing seat malfunctions that could compromise flight safety.
Enacted by the Commonwealth of Australia, this directive applies to various models within the Cessna 185 series, including the 185, 185A, 185B, 185C, 185D, 185E, A185E, and A185F. The directive includes detailed inspection and maintenance requirements for the seat tracks, rollers, washers, and other related components to ensure they meet specified tolerances and operational standards. Failure to comply with these requirements could result in grounding the aircraft until the necessary repairs and replacements are completed, thereby maintaining the high safety standards mandated by the Civil Aviation Regulations 1998.
Scope and Application
The AD/CESSNA 185/43 Amendment 1, which was issued under the authority of the Civil Aviation Regulations 1998, applies to all aircraft within the Cessna 185 Series, specifically those with model serial numbers 185, 185A, 185B, 185C, 185D, 185E, A185E, and A185F. This legislative instrument addresses critical safety measures pertaining to the seat adjustment mechanisms of these aircraft to prevent accidents stemming from mechanism failures. The directive is applicable nationally within the Commonwealth of Australia, overseen by the Civil Aviation Safety Authority. The primary focus of this legislation is to ensure the airworthiness of the specified aircraft by mandating rigorous inspections and necessary repairs or modifications to the seat adjustment systems. Exclusions or exemptions are not explicitly stated in the text, implying that all affected aircraft must comply with the outlined requirements. Compliance is further managed through subordinate instruments, which may provide additional detail or flexibility in certain circumstances.
Key Provisions
The legislative instrument F2006B05135 (AD/CESSNA 185/43) applies to specific models of Cessna 185 Series aeroplanes, including the 185, 185A, 185B, 185C, 185D, 185E, A185E, and A185F, as outlined in section (1). This Airworthiness Directive mandates several critical measures to ensure the safety and proper functioning of the seat adjustment mechanism in these aircraft. Section (1) requires a detailed inspection of the seat track(s), including measuring hole wear (section 1a), removing any dirt or debris from the seat rail holes (section 1b), ensuring the seat pin engagement depth is not less than 3.81mm (section 1c), inspecting the seat rollers and replacing any with flat spots (section 1d), measuring the wall thickness of the roller housing and tang (section 1e), checking the spring engagement in the track holes (section 1f), and inspecting the seat tracks for cracks (section 1g). Any identified issues must be resolved before the aircraft can be deemed airworthy for further flight.
In terms of compliance, section (A) specifies the timelines for adherence to the requirements. For aircraft with less than 1000 hours of time in service as of 28 January 1988, compliance must be achieved before reaching 1100 hours of service. For aircraft with more than 1000 hours of service on that date, compliance must be achieved at the next inspection for Maintenance Release issuance. Section (A) also stipulates that compliance must occur at every subsequent inspection for Maintenance Release issuance. Section (B) provides a temporary alternative: pending any component replacement necessary for full compliance with section (1), compliance with section (2) is acceptable until 30 June 1989. This allows continued flight operations while replacement parts are sourced and installed.
Failure to comply with the provisions of this legislative instrument can result in serious safety hazards. Section (C) implies that non-compliance may lead to accidents due to seat adjustment mechanism failures, as mentioned in the background. This underscores the importance of adhering to the specified requirements to prevent potential accidents. While the specific penalties for non-compliance are not detailed in the text, it is reasonable to infer that severe penalties, both civil and criminal, could apply under Australian aviation law for failure to meet airworthiness standards, potentially including fines, suspension of aircraft operation certificates, or other regulatory actions.