A-79-071
NTSB Safety Recommendation — Aviation
Recommendation text
THE NTSB RECOMMENDS THAT THE FEDERAL AVIATION ADMINISTRATION: ISSUE AN AIRWORTHINESS DIRECTIVE TO (1) DEFINE AND REQUIRE A MODIFICATION OF THE CARBURETOR HEAT VALVES ON ALL GRUMMAN G-21A AIRPLANES TO PROVIDE POSITIVE RETENTION OF THE VALVES IN THE SELECTED POSITION SO THAT THE VALVES WILL NOT CLOSE IF THE LINKAGE FAILS; AND (2) DEFINE AND REQUIRE A MODIFICATION OF THE OPERATING LEVER ON THE CARBURETOR HOT-AIR VALVE OPERATING LEVER TO FACILITATE INSTALLATION OF THE LINKAGE CONNECTING BOLT SO THAT IT WILL NOT FALL OUT IF THE NUT IS LOST.
In plain language (FlightFinder summary)
The NTSB asks the FAA to issue an airworthiness directive requiring modifications to the carburetor heat valves on Grumman G-21A airplanes. The first modification would ensure valves stay in their selected position even if the linkage fails. The second modification would improve the design of the operating lever's connecting bolt so it cannot fall out if the nut is lost.
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 4, 1980 |
| NTSB number | MIA78FA093 |
| Addressees | FAA |
External links
NTSB safety recommendations are advisory; addressees are not legally required to adopt them. Source: NTSB CAROL (public domain).