A-90-089
NTSB Safety Recommendation — Aviation
Recommendation text
THE NTSB RECOMMENDS THAT THE FEDERAL AVIATION ADMINISTRATION: EVALUATE CURRENTLY CERTIFICATED TURBINE ENGINES TO IDENTIFY THOSE ENGINE COMPONENTS THAT, IF THEY FRACTURE AND SEPARATE, COULD POSE A SIGNIFICANT THREAT TO THE STRUCTURE OR SYSTEMS OF THE AIRPLANES ON WHICH THE ENGINES ARE IN STALLED; AND PERFORM A DAMAGE TOLERANCE EVALUATION OF THESE ENGINE COMPONENTS. BASED ON THIS EVALUATION, ISSUE AN AIRWORTHINESS DIRECTIVE TO REQUIRE INSPECTIONS OF THE CRITICAL COMPONENTS AT INTERVALS BASED UPON BY THE CRACK SIZE DETECTABLE BY THE APPROVED INSPECTION METHOD USED, THE STRESS LEVEL AT VARIOUS LOCATIONS IN THE COMPONENT, AND THE CRACK PROPAGATION CHARACTERISTICS OF THE COMPONENT MATERIAL. (Supersedes Safety Recommendation A-89-096)
In plain language (FlightFinder summary)
The FAA is asked to evaluate all currently certificated turbine engines to identify components that, if fractured and separated, could significantly threaten the structure or systems of the airplanes on which they are installed. After identifying these components, the FAA must perform a damage tolerance evaluation and, based on the results, issue an airworthiness directive requiring inspections of critical components at intervals determined by detectable crack size, stress levels, and crack propagation characteristics of the material.
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 | May 28, 1993 |
| NTSB number | DCA89MA063 |
| Addressees | FAA |
External links
NTSB safety recommendations are advisory; addressees are not legally required to adopt them. Source: NTSB CAROL (public domain).