Jump to Content

Interim Recommendation issued to: Boeing Co

Recommendation details
Output No: IR19990020
Date issued: 19 March 1999
Safety action status:
Background: Why this Interim Recommendation was developed

Output text

The Bureau of Air Safety Investigation recommends that Boeing Commercial Airplane Group review the effectiveness of Service Bulletin 737-32A1224.

As a result of investigation into this occurrence, the Bureau simultaneously issues the following interim recommendations:

IR990019

The Bureau of Air Safety Investigation recommends that Boeing Commercial Airplane Group alert Boeing 737 operators to this safety deficiency and implement an appropriate inspection program.

IR990021

The Bureau of Air Safety Investigation recommends that the Federal Aviation Administration note the above safety deficiency and interim recommendations and take appropriate action as considered necessary to ensure the integrity of Boeing 737 main landing gear actuator beam arm assemblies.



IR990022

The Bureau of Air Safety Investigation recommends that the Civil Aviation Safety Authority initiate appropriate action to ensure that Australian operators of Boeing 737 aircraft immediately inspect all main landing gear actuator beam arm assemblies for evidence of cracking.

IR990023

The Bureau of Air Safety Investigation recommends that Australian operators of Boeing 737 note the above safety deficiency and interim recommendations and take appropriate action as considered necessary to ensure the integrity of Boeing 737 main landing gear actuator beam arm assemblies.

Initial response
Date issued: 06 April 1999
Response from: Boeing Co
Action status: Closed - Accepted
Response text:

Recommendation IR990020 states that Boeing should review the effectiveness of Service Bulletin 737-32A1224. Prior to the original release of the bulletin in 1989, operators were reporting medium - to - heavy corrosion of the beam arms (in addition to several reports of fractures). Following the second post - bulletin fracture report (dated 6 October 98 in the table above), we conducted a survey of operators and asked for an assessment of the condition of beam arms in service. In general, most operators who responded (representing just over 1300 airplanes) reported very little (if any) corrosion. The basic response is that, although the bulletin appears to have been effective in reducing the reported corrosion, it has not eliminated the potential for corrosion which leads to the possibility of cracking of the beam arm lugs. Therefore, we are undertaking the actions as noted in the response to recommendation IR990019 above.

 
Share this page Comment
Last update 01 April 2011