Overview

The Civil Aviation Safety Authority (CASA) issued the Airworthiness Directive (AD) AD/B737/218 on 25 December 2003 to address safety concerns related to the windshield wiper systems of specific Boeing 737 series aeroplanes. This AD was introduced to rectify issues that could lead to reduced flight crew visibility during adverse weather conditions and high workload periods, potentially causing structural damage and injuries during critical phases of flight. The directive applies to the Boeing 737-400, -500, -600, -700, and -800 series aeroplanes, as outlined in relevant Boeing Alert Service Bulletins and Service Bulletins. The policy objective is to ensure that the aeroplanes comply with safety standards by either modifying the wiring of the windshield wiper motors or replacing the motor/converters, with compliance required before 27 November 2006.

Scope and Application

The Airworthiness Directive (AD) issued by the Civil Aviation Safety Authority (CASA) under the Civil Aviation Regulations 1998 pertains to specific Boeing 737 series aeroplanes, namely the 737-400, -500, -600, -700, and -800 models. This AD is applicable to aircraft listed in Boeing Alert Service Bulletins (ASB) 737-30A1052 and 737-30A1049, which detail the modifications necessary to correct unsafe conditions related to the windshield wiper systems. The requirement is to either modify the wiring of the left and right windshield wiper motors or replace the motor/converters in the flight compartment, depending on the specific model of the aircraft, in accordance with specified Boeing Service Bulletins. Compliance with these modifications must be completed before 27 November 2006, with the directive becoming effective from 25 December 2003. This directive is issued to mitigate risks associated with reduced flight crew visibility due to stalled wiper motors during heavy precipitation, which could lead to structural damage and injury to crew and passengers during critical phases of flight. The AD is applicable on a Commonwealth-wide basis, as it is notified in the Commonwealth of Australia Gazette.

Key Provisions

This Airworthiness Directive (AD) applies to specific models of Boeing 737 aeroplanes, namely the 737-400 and -500 series, and the 737-600, -700, and -800 series. The directive mandates two primary actions to address safety concerns related to the windshield wipers. For the 737-400 and -500 series, the directive requires either a modification to the wiring of the windshield wiper motors in the flight compartment, including adjustments to wire bundles, the reduction of wiper blade force, and an operational test of the system in accordance with Boeing Alert Service Bulletin (ASB) 737-30A1052. Alternatively, the left and right windshield wiper motor/converters can be replaced according to Boeing Service Bulletin (SB) 737-30-1055, Revision 1, with an operational test following the replacement. For the 737-600, -700, and -800 series, the directive provides two options: either modify the wiring as per ASB 737-30A1049, or replace the windshield wiper motor/converters in accordance with SB 737-30-1054, Revision 1. Replacement of the motor/converters prior to the AD's effective date is also considered compliant. The AD imposes obligations on the operators of the specified Boeing 737 models to ensure that the prescribed actions are taken. This includes the modification of the wiring or the replacement of the windshield wiper motor/converters, as outlined in the AD. Operators must adhere to the detailed instructions provided in the relevant Boeing service bulletins to achieve compliance. Additionally, operators must ensure that these modifications or replacements are completed before the specified compliance date of 27 November 2006. Failure to comply with these requirements could result in compromised flight safety, particularly during adverse weather conditions and periods of high crew workload. Failure to comply with the AD can lead to serious consequences, including potential damage to the aircraft structure and injury to flight crew or passengers. The AD specifies that non-compliance with the mandated actions could result in unsafe conditions that compromise the visibility of the flight crew, especially during critical phases of flight such as final approach and landing. Although specific penalties are not detailed in the AD, non-compliance with such safety directives can lead to enforcement actions by the Civil Aviation Safety Authority (CASA), which may include fines, operational restrictions, or other regulatory sanctions. The severity of these penalties may depend on the extent and impact of the non-compliance on flight safety.