2 May 2002
B.F. Goodrich P/N 133-893-2
The purpose of this Alert is to notify operators of a potentially serious problem that, if undetected, could cause unexpected brake lock up.
Recently, Transport Canada received a report from an operator that has experienced multiple brake failures due to broken brake stators. A search of the Service Difficulty Reporting (SDR) database shows four Cessna 500 Series brake failures due to broken stators.
During a Phase 5 inspection when the stators on the brake assemblies were checked at approximately 600 landings. One disk in the stack was cracked through with all the other holes cracked approximately 75%. Most of the expansion slots were found completely closed off at the outer edge. This post service bulletin unit could have hard failed in a very short period of time if not detected.
B.F. Goodrich manufactures the brake assembly (P/N 1528-4/-6) and Cessna has issued Service Bulletins (SB) 550-32-47/-48, which had been complied with on these units.
Transport Canada highly recommends that operators check these brakes at your earliest convenience to prevent possible brake lock up due to broken stator assemblies.
Any defects or further occurrences should be reported by sending a Service Difficulty Report to Transport Canada, Continuing Airworthiness, Ottawa.
For further information, contact a Transport Canada Centre, or Mr. Steve Dudka, Continuing Airworthiness, Ottawa, telephone (613) 952-4361, facsimile (613) 996-9178 or e-mail firstname.lastname@example.org.
For Director, National Aircraft Certification
- Broken Stator Disk - Immediately remove the brake assemply from service
- Before inspection of statos disks, use a rag or a soft-bristle bruch to clean the stop hole at the end of each long expansion slot.
Figure 3. Stator Disk Examination / Examen du disquea
Chief, Continuing Airworthiness