A-91-020
NTSB Safety Recommendation — Aviation
Recommendation text
THE NTSB RECOMMENDS THAT THE FEDERAL AVIATION ADMINISTRATION: IN COOPERATION WITH THE FRENCH DIRECTION GENERALE DE L'AVIATION CIVILE, AVIONS DE TRANSPORT REGIONAL, AND MESSIER BUGATTI, DEVELOP AN ATR 42 AIRPLANE INSPECTION PROGRAM THAT CAN DETERMINE IF MAIN LANDING GEAR SIDE BRACE ASSEMBLY LOWER ARMS (P/N D56779) WITH INTACT SEALANT AROUND THE SPHERICAL BEARING AT THE BOTTOM END OF THE ARM ARE SUBJECT TO CORROSION ON THE BORE SURFACE, THE SURFACE THAT CONTACTS THE BEARING'S OUTER RACE. BASED ON THE RESULTS OF THIS INSPECTION PROGRAM, DETERMINE IF THE SCOPE OF THE AIRWORTHINESS DIRECTIVE DESCRIBED IN SAFETY RECOMMENDATION A-91-19 SHOULD BE EXPANDED TO REQUIRE ULTRASONIC INSPECTIONS OF THE LOWER ARMS ON WHICH THE SEALANT IS NOT CRACKED OR DAMAGED.
In plain language (FlightFinder summary)
The NTSB asks the FAA to work with French authorities, ATR, and Messier Bugatti to create an inspection program for ATR 42 main landing gear side brace lower arms (part number D56779). The program should check whether corrosion can develop on the bore surface under intact sealant around the spherical bearing. Then, based on the findings, the FAA must decide if the existing airworthiness directive should be expanded to require ultrasonic inspections on arms where the sealant is not cracked or damaged.
This plain-language summary is written by FlightFinder to explain the recommendation above. It is not the official wording — the verbatim NTSB text is quoted above.
Details
| Status | Closed - Acceptable Alternate Action |
|---|---|
| Mode | Aviation |
| Closed | Feb 10, 1993 |
| NTSB number | MIA91IA032 |
| Addressees | FAA |
External links
NTSB safety recommendations are advisory; addressees are not legally required to adopt them. Source: NTSB CAROL (public domain).