AIRWORTHINESS DIRECTIVE
For the reasons set out in the background section, the CASA delegate whose signature appears below issues the following Airworthiness Directive (AD) under subregulation 39.1 (1) of CASR 1998. The AD requires that the action set out in the requirement section (being action that the delegate considers necessary to correct the unsafe condition) be taken in relation to the aircraft or aeronautical product mentioned in the applicability section: (a) in the circumstances mentioned in the requirement section; and (b) in accordance with the instructions set out in the requirement section; and (c) at the time mentioned in the compliance section.
British Aerospace BAe 146 Series Aeroplanes
AD/BAe 146/110 Pressure Floor Over Main Landing Gear Bay
5/2004
Applicability: Model BAe 146 Series aircraft without Modification HCM00972A or HCM00972C incorporated.
Requirement: 1. Aircraft without Modification HCM00972A or HCM00972C and without Modification HCM00744M or HCM00850A:
- Carry out an initial inspection of the pressure floor over the main landing gear bay for cracks, in accordance with paragraph 2 of BAE Systems Service Bulletin (SB) 53-170, dated 8 August 2003.
b. Carry out the initial inspection in accordance with paragraph 2 of SB 53-170.
c. Repeat the inspection in accordance with paragraph 2 of SB 53-170.
Where cracks or other damage are detected during any inspection, before further flight, repair in accordance with SB 53-170 or an approved repair scheme.
2. Aircraft without Modification HCM00972A or HCM00972C and with Modification HCM00744M or HCM00850A:
- Carry out an initial inspection of the pressure floor over the main landing gear bay for cracks, in accordance with paragraph 2 of SB 53-170.
b. Carry out the initial inspection in accordance with paragraph 2 of SB 53-170.
c. Repeat the inspection in accordance with paragraph 2 of SB 53-170.
Where cracks or other damage are detected during any inspection, before further flight, repair in accordance with SB 53-170 or an approved repair scheme.
Note: UK CAA AD G-2004-0004 refers.
British Aerospace BAe 146 Series Aeroplanes
AD/BAe 146/110 (continued)
Compliance: 1.a. Before the accumulation of 15,000 flights.
1.b. If the aircraft has exceeded 14,500 flights at the effective date of this Directive, within a further 500 flights.
1.c. At intervals not to exceed 1,000 flights.
2.a. Before the accumulation of 15,000 flights.
2.b. If the aircraft has exceeded 14,000 flights at the effective date of this Directive, within a further 1,000 flights.
2.c. At intervals not to exceed 3,000 flights.
This Airworthiness Directive becomes effective on 13 May 2004.
Background: Fatigue induced cracking can occur in the fuselage pressure skin above the left and right main landing gear bay as a result of cabin pressure cycling. The problem was previously recognised and the affected area is already inspected as part of SSI task 53-20-153. Significant cracking in the affected area of the fuselage skin has been reported following unrelated maintenance, demonstrating that the published inspection technique does not guarantee that all damage will be detected.
David Villiers
Delegate of the Civil Aviation Safety Authority 2 April 2004
The above AD is notified in the Commonwealth of Australia Gazette on 21 April 2004.
Overview
The Airworthiness Directive AD/BAe 146/110, issued in 2004, addresses a specific safety concern identified in British Aerospace BAe 146 Series aircraft. This legislation was enacted by the Civil Aviation Safety Authority (CASA) to correct an unsafe condition related to fatigue-induced cracking in the fuselage pressure skin above the left and right main landing gear bay. This problem arises due to cabin pressure cycling, which was previously recognised but not fully mitigated by existing inspection techniques. The directive aims to ensure the safety of the aircraft by mandating regular inspections and repairs as necessary, thus minimising the risk of structural failure during flight. The policy objective is to enhance air safety by implementing rigorous maintenance protocols for the specified aircraft models.
Scope and Application
The Airworthiness Directive issued under subregulation 39.1 (1) of the Civil Aviation Safety Regulations 1998 pertains to the British Aerospace BAe 146 Series aeroplanes and specifically addresses a safety concern related to the pressure floor over the main landing gear bay. This directive applies to BAe 146 Series aircraft that do not have Modification HCM00972A or HCM00972C incorporated, irrespective of whether they have Modification HCM00744M or HCM00850A. The directive mandates that an initial inspection of the pressure floor over the main landing gear bay must be conducted to detect any cracks or damage, with subsequent inspections and repairs as required, to ensure the airworthiness of the aircraft. The directive is issued by a delegate of the Civil Aviation Safety Authority and is effective from 13 May 2004, with inspections required at specified intervals and within certain flight limits. This AD is applicable across the Commonwealth of Australia and does not explicitly state exclusions or exemptions, but it does specify conditions under which inspections and repairs must be carried out. The AD may be supplemented by subordinate instruments that provide further detail on the inspection and repair processes.
Key Provisions
The main sections of this Airworthiness Directive (AD) outline specific requirements for inspections and repairs of the pressure floor over the main landing gear bay of British Aerospace BAe 146 Series aeroplanes. Section (a) specifies the applicability, detailing that the AD applies to BAe 146 Series aircraft that do not have Modification HCM00972A or HCM00972C incorporated. The requirement section (b) mandates that an initial inspection for cracks be conducted in accordance with BAE Systems Service Bulletin (SB) 53-170, dated 8 August 2003, and that this inspection must be repeated at intervals not exceeding 1,000 flights or 3,000 flights, depending on the aircraft's flight history at the effective date of the AD. If cracks or other damage are found, repairs must be carried out following SB 53-170 or an approved repair scheme before any further flight. The compliance section (c) details the specific timings for these inspections based on the aircraft's flight history at the effective date of the AD.
The obligations imposed by this AD on the parties it governs include the mandatory inspection of the pressure floor over the main landing gear bay for cracks, with subsequent repairs if any damage is detected. Operators of the BAe 146 Series aircraft must adhere to the specified inspection intervals and ensure that any detected cracks or damage are repaired according to the instructions provided in SB 53-170 or an approved alternative. This ensures that the aircraft remain airworthy and safe for operation, addressing the risk of fatigue-induced cracking in the fuselage skin above the main landing gear bay.
Breaches of this AD can lead to serious consequences. While the AD itself does not explicitly state specific penalties for non-compliance, failure to adhere to airworthiness directives can result in severe civil or criminal consequences under the Civil Aviation Safety Authority (CASA) regulations. Non-compliance can lead to the grounding of the affected aircraft, which can result in significant operational disruptions and financial losses for operators. In more severe cases, where non-compliance contributes to an accident or incident, operators could face criminal charges and penalties under aviation safety laws, potentially including substantial fines and imprisonment. The overarching goal of the AD is to maintain the highest safety standards in aviation, and non-compliance is taken very seriously.