A-93-154
NTSB Safety Recommendation — Aviation
Recommendation text
THE NTSB RECOMMENDS THAT THE FEDERAL AVIATION ADMINISTRATION: IDENTIFY AIRPLANES THAT CAN, THROUGH A COMBINATION OF THE RESONANT RPM, THE GROUND IDLE RPM RANGE, AND REPAIR LIMITS AT THE BLADE TIP, PRODUCE THE REACTIONLESS MODE IN THE NORMAL OPERATING RANGE. FOR THOSE AIRPLANES CONTAINING HARTZELL HUBS AT RISK FOR REDUCED FATIGUE PROPERTIES (MANUFACTURED PRIOR TO APRIL 1984), REQUIRE INSPECTION FOR CRACKS IN THE PILOT TUBE HOLE.
In plain language (FlightFinder summary)
The National Transportation Safety Board asks the Federal Aviation Administration to identify airplanes that, based on a combination of resonant RPM, ground idle RPM range, and blade-tip repair limits, could experience the reactionless mode during normal operation. For those airplanes equipped with Hartzell hubs at risk (manufactured before April 1984), the FAA should require inspections for cracks in the pilot tube hole.
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 | Jul 17, 1995 |
| NTSB number | DCA93GA042 |
| Addressees | FAA |
External links
NTSB safety recommendations are advisory; addressees are not legally required to adopt them. Source: NTSB CAROL (public domain).