Overview

The Civil Aviation Safety Authority (CASA) has enacted the Airworthiness Directive AD/BEECH 55/91 to address the problem of flap flex shaft separations in Beechcraft 55, 58 and 95-55 (Baron) Series Aeroplanes, which have led to flap asymmetric situations. These failures have been traced to improper heat treatment of flex shafts, particularly those manufactured between January 2000 and April 2001. The directive aims to ensure that aircraft are maintained to a safe standard by mandating inspections and replacements of affected components. The directive applies to all serial numbers of the specified Beechcraft models and requires the review of aircraft records, inspection of identification labels for manufacture dates, and replacement of flex shafts manufactured within the specified timeframe. Compliance must be achieved within 25 flight hours from the effective date of the directive.

Scope and Application

The Airworthiness Directive issued by the Civil Aviation Safety Authority (CASA) under subregulation 39.1 (1) of the Civil Aviation Regulations 1998 specifically targets the Beechcraft 55, 58 and 95-55 (Baron) Series Aeroplanes. The AD applies to all serial numbers of these aircraft models and mandates certain actions to address an unsafe condition related to the flap flex shaft assembly. The directive applies to aircraft operators and owners who must review their aircraft records to determine if either the left-hand (LH) or right-hand (RH) flap flex shaft, or the flap actuator, has been replaced since 1 March 2000. If these components have not been replaced since the specified date, no further action is required, and an appropriate certification must be made in the aircraft log book. If replacement has occurred since 1 March 2000, the identification label for the manufacture date of the flap flex shaft assemblies must be inspected. Flex shafts manufactured before January 2000 and after April 2001 do not require replacement, whereas those manufactured between January 2000 and April 2001 must be replaced. The directive also references FAA AD 2001-23-10 and notes that Beech 58 aircraft with certain serial numbers may have had a discrepant flap flex shaft installed during production, although these aircraft are not currently on the Australian register. Compliance with the AD must be achieved within 25 flight hours from its effective date of 30 January 2002.

Key Provisions

The Airworthiness Directive (AD) AD/BEECH 55/91, issued under subregulation 39.1(1) of the Civil Aviation Regulations 1998 (CAR 1998), applies to specified Beechcraft 55, 58 and 95-55 (Baron) Series Aeroplanes (section 1). Specifically, the AD mandates a review of aircraft records to determine if certain components—the left-hand (LH) or right-hand (RH) flap flex shaft or the flap actuator—have been replaced since 1 March 2000. If these components have not been replaced since that date, no further action is required, but an appropriate certification must be made in the aircraft log book (section 2(1)). If any of these components have been replaced since 1 March 2000, the identification label for the manufacture date of the flex shafts must be inspected in accordance with Raytheon Service Bulletin 27-3478. Flex shafts manufactured before January 2000 or after April 2001 do not require replacement. However, flex shafts manufactured between January 2000 and April 2001 must be replaced (section 2(2)-(3)). The AD imposes specific obligations on the operators and owners of the affected aircraft. Operators must review their aircraft records to ascertain whether the LH or RH flap flex shaft or the flap actuator has been replaced since 1 March 2000. If these components have not been replaced, they must certify this in the aircraft log book. If any of these components have been replaced, operators must inspect the identification label for the manufacture date of the flex shaft assemblies. Flex shafts manufactured outside the specified January 2000 to April 2001 period do not require replacement. Flex shafts manufactured within this period must be replaced before the aircraft can be flown again. These actions must be completed within 25 flight hours from the effective date of the AD (section 3(1)-(3)). Failure to comply with the AD could result in serious safety issues due to potential flap asymmetric situations caused by flap flex shaft separations. Such non-compliance could lead to civil or criminal penalties under the Civil Aviation Act 1988, which governs aviation safety in Australia. While specific penalties are not detailed in the AD itself, non-compliance with airworthiness directives can result in significant fines and potential grounding of the aircraft, which could impact the operator's ability to conduct flights legally. The seriousness of the potential consequences underscores the importance of adhering to the AD's requirements.