A-86-024
NTSB Safety Recommendation — Aviation
Recommendation text
THE NTSB RECOMMENDS THAT THE FEDERAL AVIATION ADMINISTRATION: ISSUE AN AIRWORTHINESS DIRECTIVE IN ADDITION TO AD 80-14-12 TO REQUIRE A ONE-TIME ULTRASONIC OR EDDY CURRENT INSPECTION OF PARSONS COMPANY MAIN ROTOR BLADES (PN 2253-1101-04) WITH MORE THAN 3,000 HOURS ACCUMULATED TIME USE ON HILLER AVIATION MODEL UH-12 HELICOPTERS FOR EVIDENCE OF BONDING VOIDS AND FATIGUE CRACKS PARTICULARLY IN THE AREA OF THE INTERFACE BETWEEN THE SPAR LOWER SURFACE LEADING EDGE AND THE EXTERNAL SPAR DOUBLER. DATA FROM THIS ONE-TIME INSPECTION PROGRAM SHOULD BE EVALUATED TO DETERMINE IF ANY FURTHER ULTRASONIC OR EDDY CURRENT INSPECTIONS ARE NECESSARY OR IF THE APPROVED SERVICE LIFE SHOULD BE REDUCED.
In plain language (FlightFinder summary)
The Federal Aviation Administration is asked by the NTSB to issue an airworthiness directive requiring a one-time ultrasonic or eddy current inspection of Parsons Company main rotor blades (PN 2253-1101-04) with over 3,000 hours on Hiller Aviation Model UH-12 helicopters. The inspection must look for bonding voids and fatigue cracks, especially at the interface between the spar lower surface leading edge and the external spar doubler. Data from this program should be evaluated to determine if further inspections are needed or if the approved service life should be reduced.
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 | Jan 13, 1988 |
| NTSB number | SEA84LA174 |
| Addressees | FAA |
External links
NTSB safety recommendations are advisory; addressees are not legally required to adopt them. Source: NTSB CAROL (public domain).