A-83-012
NTSB Safety Recommendation — Aviation
Recommendation text
SINCE THE CESSNA MODEL 404 AIRPLANE IS USED FREQUENTLY IN COMMUTER OPERATIONS, THE SAFETY BOARD RECOMMENDS THAT THE FEDERAL AVIATION ADMINISTRATION: REVIEW THE DESIGN CRITERIA OF THE ALUMINUM HYDRAULIC LINES IN CESSNA MODEL 404 AIRPLANES TO DETERMINE THAT THE FATIGUE LIMIT OF THE TUBING, THE PRESCRIBED INSTALLATION BEND RADII, AND THE CYCLIC LOADS DO NOT RESULT IN AN UNACCEPTABLE MARGIN OF SAFETY AS TO FATIGUE AND FAILURE OF THE HYDRAULIC LINES; IF THE MARGIN OF SAFETY IS NOT ADEQUATE, REQUIRE THAT THE HYDRAULIC LINES (1) BE INSPECTED AT APPROPRIATE INTERVALS BY A METHOD THAT WILL REVEAL FATIGUE CRACKS IN THE LINES, OR (2) BE REPLACED AT A SPECIFIED SERVICE LIFE OR TIME THAT WILL FORESTALL FATIGUE FAILURE OF THE LINES.
In plain language (FlightFinder summary)
The Federal Aviation Administration is asked to review the design criteria of aluminum hydraulic lines in Cessna Model 404 airplanes, specifically the fatigue limit, installation bend radii, and cyclic loads, to ensure they do not create an unacceptable margin of safety regarding fatigue and failure. If the margin is found inadequate, the FAA should require either periodic inspections to detect fatigue cracks or replacement of the lines at a specified service life to prevent fatigue failure.
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 6, 1984 |
| NTSB number | ATL82IA139 |
| Addressees | FAA |
External links
NTSB safety recommendations are advisory; addressees are not legally required to adopt them. Source: NTSB CAROL (public domain).