Cessna 188 (Agwagon) Series Aeroplanes
AD/CESSNA 188/42
Amdt 1
Applicability: Model
Seat Adjustment Mechanism 9/88
Serial Number
188, A188, A188A, 188B, A188B, T188C.
Requirement: Part 1:
All
(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 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
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 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
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 188 (Agwagon) Series Aeroplanes AD/CESSNA 188/42 Amendment 1, enacted as part of the Civil Aviation Regulations 1998, addresses the safety issue of seat adjustment mechanism failures that have resulted in accidents. This legislation was introduced to enhance the safety of flight operations by ensuring that the seat adjustment mechanisms are maintained and inspected to prevent potential failures. The Civil Aviation Safety Authority, under the authority of the Commonwealth of Australia, established these directives to mitigate risks associated with seat adjustment failures, aiming to ensure that all components are in a serviceable condition and that any necessary repairs or replacements are carried out before further flight. The policy objective is to maintain the highest standards of aviation safety by enforcing stringent inspection and maintenance protocols for critical aircraft components.
Scope and Application
The Cessna 188 (Agwagon) Series Aeroplanes AD/CESSNA 188/42 Amendment 1, applicable to specific serial numbers, aims to ensure the airworthiness of the aircraft by addressing issues with the seat adjustment mechanism, which has been linked to accidents. This legislative instrument applies to aircraft owners, operators, and maintenance personnel, focusing on the inspection and maintenance of seat tracks, rollers, and related components. The geographic reach of this legislation is national, as it is issued under the Civil Aviation Regulations 1998, administered by the Civil Aviation Safety Authority (CASA). The requirements must be met for aircraft operating within Australia and must adhere to the outlined standards to maintain a Maintenance Release. This Airworthiness Directive does not specify exclusions but provides exemptions for compliance timing based on the aircraft's service hours as of a particular date. The application of this directive can be further refined through subordinate instruments issued by CASA, ensuring that any updates or clarifications are incorporated into the regulatory framework.
Key Provisions
The AD/CESSNA 188/42 Amendment 1 mandates specific requirements for the seat adjustment mechanisms of certain Cessna 188 series aeroplanes, identified by serial numbers 188, A188, A188A, 188B, A188B, and T188C. The key sections of the legislation focus on detailed inspections and modifications to ensure safety. In Part 1, Section (a) requires an examination of each hole in the seat track(s) for excessive wear. If any hole's wear exceeds 10.67mm (0.42") to a maximum depth of 3.81mm (0.15"), the seat track must be replaced before further flight. Section (b) mandates a visual inspection for dirt and debris in the seat rail holes, which must be removed to prevent issues with the seat pin(s). Section (c) involves lifting the forward edge of each seat to eliminate vertical play and ensuring that each seat pin engages at least 3.81mm (0.15"); if not, the necessary components must be replaced or repaired. Section (d) requires inspecting seat rollers for flat spots and ensuring they turn and move freely, replacing any defective parts and addressing any binding issues. Section (e) involves measuring the wall thickness of the roller housing and tang, replacing the roller housing if the tang's thickness is less than half of the housing's thickness. Section (f) necessitates checking the springs that keep the lock pins in position, replacing any spring that fails to provide positive engagement. Finally, Section (g) mandates a visual inspection for cracks in the seat tracks, with any limitations due to cracking endorsed on the Maintenance Release, and replacing any seat rail that exceeds the specified crack criteria.
The legislation imposes several obligations on the parties or entities it governs. Firstly, it requires the inspection and maintenance of seat adjustment mechanisms as outlined in Part 1, ensuring that all components are in good working condition and free from wear and debris. Secondly, it mandates modifications to the seat adjustment mechanisms to limit seat travel, as specified in Part 2. For aircraft with less than 1000 hours of time in service as at 28 January 1988, these modifications must be completed before the aircraft reaches 1100 hours. For aircraft with more than 1000 hours of time in service as at that date, modifications must be completed at the next inspection for Maintenance Release issue after 28 January 1988, and then at each subsequent inspection for Maintenance Release issue. Pending any necessary component replacements to fully comply with Part 1, compliance with Part 2 is acceptable until 30 June 1989.
The legislation also outlines the consequences of non-compliance. Failure to adhere to the requirements set forth in the AD/CESSNA 188/42 Amendment 1 could result in severe safety hazards, potentially leading to accidents due to seat adjustment mechanism failure. While the specific penalties for non-compliance are not detailed in the provided text, non-compliance with Civil Aviation Regulations can generally lead to significant civil and criminal penalties, including fines and imprisonment. The exact penalties would depend on the specific regulations and the severity of the breach, but they can be substantial, reflecting the critical nature of aviation safety standards.