AD/B747/38 Amdt 4 - Body Station 1241 Bulkhead Splice

Overview

The Civil Aviation Regulations 1998, amended by the 1995 instrument F2006B03218, focus on enhancing the safety of Boeing 747 series aeroplanes, specifically addressing structural integrity concerns identified in the body station 1241 bulkhead splice. This legislative instrument was enacted to rectify the problem of undetected cracks in the splice strap and forging of the body station 1241, which could potentially lead to severe consequences such as loss of cabin pressure and structural failure. The regulation mandates inspections for specified Boeing 747 aircraft serial numbers, in line with the Boeing Service Bulletin 747-53-2283, Revision 4, and the Federal Aviation Administration Advisory Directive 92-08-02. This directive aims to ensure compliance by specifying the inspection thresholds and intervals, thereby reinforcing aviation safety standards as recommended by the Ageing Fleet B747 Structures Working Group.

Scope and Application

The Civil Aviation Regulations 1998, under PART 39 - 105, specifically address the airworthiness of Boeing 747 series aeroplanes through the Airworthiness Directive AD/B747/38 Amendment 4, which pertains to the inspection of the Body Station 1241 Bulkhead Splice. This directive applies to specific Boeing 747 aircraft, identified by their serial numbers within particular groups as detailed in Boeing Service Bulletin 747-53-2283, Revision 4. The requirement entails a thorough inspection of the Body Station 1241 splice strap and forging using visual, eddy current, and ultrasonic methods in accordance with the specified service bulletin. This directive is intended to ensure the safety and airworthiness of the aircraft by addressing the issue of cracks found in the splice strap and forging, which could potentially lead to severe consequences such as loss of cabin pressure and structural failure. Compliance with the directive necessitates inspections at the thresholds and intervals outlined in Boeing Service Bulletin 747-53-2283, Revision 4, with the effective date for the changes introduced by this Amendment being 25 May 1995.

Key Provisions

The Civil Aviation Regulations 1998, specifically Part 39 - 105, mandates the inspection of certain Boeing 747 series aeroplanes under Amendment 4, which pertains to the Body Station 1241 Bulkhead Splice. This directive applies to Boeing 747 aircraft with serial numbers 1-675, 677-678, 680-684, and 686-689 in 18 distinct groups as outlined in Boeing Service Bulletin (SB) 747-53-2283, Revision 4. The requirement set forth in this amendment is for a thorough inspection of the body station (BS) 1241 splice strap and forging. This inspection must be conducted visually, by eddy current, and ultrasonically, adhering to the guidelines stipulated in Boeing SB 747-53-2283, Revision 4. Notably, this amendment references the Federal Aviation Administration (FAA) AD 92-08-02. Compliance with this directive mandates inspections at the specified thresholds and intervals as detailed in Boeing SB 747-53-2283, Revision 4, with the effective date of the changes introduced by this amendment being 25 May 1995. The Civil Aviation Regulations 1998 impose specific obligations on the parties or entities governed by this legislation. Aircraft operators and maintenance organisations must ensure that the inspections of the BS 1241 splice strap and forging are conducted in accordance with the detailed requirements of Boeing SB 747-53-2283, Revision 4. This includes performing visual inspections, eddy current tests, and ultrasonic examinations. The inspections are to be carried out at the intervals and thresholds specified in the referenced service bulletin. Failure to comply with these inspection requirements may result in non-compliance with the Civil Aviation Regulations 1998 and could lead to the grounding of affected aircraft until the necessary inspections are completed and any required repairs are made. The Civil Aviation Regulations 1998, under the authority of the Civil Aviation Safety Authority, establish various consequences for breaches of the regulations. Failure to adhere to the requirements set forth in Amendment 4, including the mandated inspections of the BS 1241 splice strap and forging, may result in enforcement actions by the Civil Aviation Safety Authority. Potential consequences include fines, the issuance of directives to rectify non-compliant conditions, and, in severe cases, the suspension or revocation of the aircraft's airworthiness certificate. Additionally, the safety of the aircraft and its passengers could be compromised if undetected cracks in the BS 1241 splice strap and forging lead to loss of cabin pressure or structural failure. The regulations are designed to prevent such outcomes through stringent inspection and maintenance requirements.