A-89-001
NTSB Safety Recommendation — Aviation
Recommendation text
THE NTSB RECOMMENDS THAT THE FEDERAL AVIATION ADMINISTRATION: AMEND AIRWORTHINESS DIRECTIVE 88-01-07: (1) TO DECREASE THE NUMBER OF CYCLES BETWEEN ULTRASONIC INSPECTION OF THE AFT ATTACHMENT CONE BOLTS FOR THE ENGINE; (2) TO REQUIRE A CHECK OF THE PRELOAD TORQUE OF THE AFT CONE BOLT CONCURRENTLY WITH THESE ULTRASONIC INSPECTIONS, AND UNTIL REPETITIVE INSPECTION INDICATES THAT THE TORQUE PRELOAD HAS STABILIZED, TO REQUIRE MORE FREQUENT INSPECTION AND TORQUE CHECK INTERVALS FOR BOLTS THAT HAVE BEEN IN SERVICE WITH LESS THAN SPECIFIED TORQUE; AND (3) TO ACCELERATE THE REQUIRED INSTALLATION OF THE NEW SECONDARY SUPPORT STRUCTURE AT THE ENGINE AFT ATTACHMENT. (URGENT)
In plain language (FlightFinder summary)
The NTSB asks the FAA to amend Airworthiness Directive 88-01-07 with three changes: reduce the number of cycles between ultrasonic inspections of the engine's aft attachment cone bolts; require checking the preload torque of the aft cone bolt during those inspections and, until torque stabilizes, require more frequent inspection and torque checks for bolts that have been in service with less than specified torque; and accelerate the required installation of the new secondary support structure at the engine aft attachment. The recommendation is marked urgent.
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 Action |
|---|---|
| Mode | Aviation |
| Closed | Mar 19, 1990 |
| NTSB number | CHI89MA046 |
| Addressees | FAA |
External links
NTSB safety recommendations are advisory; addressees are not legally required to adopt them. Source: NTSB CAROL (public domain).