A-74-090
NTSB Safety Recommendation — Aviation
Recommendation text
MODIFY THE PERIODIC MAINTENANCE CHECK PROCEDURES FOR ALL DIGITAL FLIGHT DATA RECORDING SYSTEMS WHICH USE LOCKHEED AIRCRAFT SERVICE COMPANY RECORDERS, AS FOLLOWS: A. REVISE THE MAINTENANCE CHECK INTERVALS SO THAT THEY ARE COMMENSURATE WITH EACH OPERATOR'S MEAN-TIME-BETWEEN-FAILURE RATE, BUT DO NOT EXCEED 3,000 HOURS. B. REQUIRE AT EACH PRESCRIBED MAINTENANCE CHECK A READOUT OF ACTUAL FLIGHT DATA FOR ALL PARAMETERS EITHER BY COMPUTER OR BY ANALOG METHODS FOR PROPER RECORDER PERFORMANCE. C. REQUIRE THAT THE TAPE HEADS IN THE RECORDERS BE CLEANED EVERY 2,000 HOURS OR AT EVERY MAINTENANCE CHECK PERIOD, WHICHEVER IS LATER(NOT TO EXCEED 3,000 HOURS). D. REQUIRE MAINTENANCE CHECKS EVERY 500 HOURS ON DFDR SYSTEMS WHENEVER A MAJOR MODIFICATION IS MADE AS A RESULT OF SERVICE DIFFICULTIES UNTIL A LONGER CHECK PERIOD CAN BE JUSTIFIED BY THE OPERATOR'S NEW MEAN-TIME-BETWEEN-FAILURE RATE FOR THE SYSTEM.
In plain language (FlightFinder summary)
The National Transportation Safety Board advises the Federal Aviation Administration to update maintenance rules for digital flight data recorders used on Lockheed aircraft. These updates require more frequent checks based on failure rates, mandatory verification of recorded flight data during inspections, and regular cleaning of recording heads every two thousand hours or less. The goal is to ensure these critical safety devices function correctly by preventing data loss due to wear or technical issues.
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 | Oct 1, 1975 |
| NTSB number | MIA75AM002 |
| Addressees | FAA |
External links
NTSB safety recommendations are advisory; addressees are not legally required to adopt them. Source: NTSB CAROL (public domain).