|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||0601 To 1200|
|Locale Reference||airport : 5j9|
|Altitude||agl bound lower : 0|
agl bound upper : 0
|Operator||general aviation : instructional|
|Make Model Name||Small Aircraft, High Wing, 1 Eng, Retractable Gear|
|Flight Phase||landing other|
|Function||other personnel other|
|Qualification||other other : other|
pilot : instrument
pilot : commercial
pilot : cfi
|Experience||flight time last 90 days : 100|
flight time total : 8000
flight time type : 500
|Function||instruction : trainee|
|Qualification||pilot : private|
|Anomaly||aircraft equipment problem : critical|
other anomaly other
|Independent Detector||other flight crewa|
|Resolutory Action||aircraft : equipment problem dissipated|
flight crew : declared emergency
none taken : detected after the fact
During landing roll-out right main landing gear disc brake pad failed. A small fire occurred which self extinguished. No damage to aircraft. Inspection by an ia revealed the failed brake pad lining had broken, allowing the retaining rivet to contact the wheel disc. Time in service of part: approximately 10 hours. The operator of the aircraft has a fleet of 5 small aircraft aircraft as well as numerous other fleet aircraft. An inspection of repair records revealed that since 9/91, a new composition brake pad lining has been in use. The new composition apparently does not contain asbestos. In my opinion the removal of the asbestos has apparently weakened the structure of the pad lining and reduced the effectiveness of the lining to withstand the thermal stresses encountered during the landing roll, especially during maximum braking could have catastrophic results. I recommend that a search of the sdr database be conducted for similar occurrences and if a correlation is found between the type of occurrence and the change in pad composition, a suitability study be conducted to find a suitable material for use in these brake systems.
Original NASA ASRS Text
Title: GA SMA HAD A BRAKE FIRE AFTER LNDG. RPTR THINKS NEW NON ASBESTOS LINING SHOULD BE REEVALUATED.
Narrative: DURING LNDG ROLL-OUT R MAIN LNDG GEAR DISC BRAKE PAD FAILED. A SMALL FIRE OCCURRED WHICH SELF EXTINGUISHED. NO DAMAGE TO ACFT. INSPECTION BY AN IA REVEALED THE FAILED BRAKE PAD LINING HAD BROKEN, ALLOWING THE RETAINING RIVET TO CONTACT THE WHEEL DISC. TIME IN SVC OF PART: APPROX 10 HOURS. THE OPERATOR OF THE ACFT HAS A FLEET OF 5 SMA ACFT AS WELL AS NUMEROUS OTHER FLEET ACFT. AN INSPECTION OF REPAIR RECORDS REVEALED THAT SINCE 9/91, A NEW COMPOSITION BRAKE PAD LINING HAS BEEN IN USE. THE NEW COMPOSITION APPARENTLY DOES NOT CONTAIN ASBESTOS. IN MY OPINION THE REMOVAL OF THE ASBESTOS HAS APPARENTLY WEAKENED THE STRUCTURE OF THE PAD LINING AND REDUCED THE EFFECTIVENESS OF THE LINING TO WITHSTAND THE THERMAL STRESSES ENCOUNTERED DURING THE LNDG ROLL, ESPECIALLY DURING MAX BRAKING COULD HAVE CATASTROPHIC RESULTS. I RECOMMEND THAT A SEARCH OF THE SDR DATABASE BE CONDUCTED FOR SIMILAR OCCURRENCES AND IF A CORRELATION IS FOUND BTWN THE TYPE OF OCCURRENCE AND THE CHANGE IN PAD COMPOSITION, A SUITABILITY STUDY BE CONDUCTED TO FIND A SUITABLE MATERIAL FOR USE IN THESE BRAKE SYSTEMS.
Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.