A-73-077
NTSB Safety Recommendation — Aviation
Recommendation text
ISSUE AN AIRWORTHINESS DIRECTIVE WHICH WOULD REQUIRE: (A) THAT ALL BOEING 707/720 AIRCRAFT BE SUBJECTED TO AN ELEVATOR BREAKOUT FORCE CHECK IN ACCORDANCE WITH THE APPROVED MAINTENANCE PROCEDURES AT THE NEXT SCHEDULED MAINTENANCE VISIT; AND (B) THAT THOSE AIRCRAFT ON WHICH THE BREAKOUT FRICTION DETERMINED IN PART (A) EXCEEDS THE MAXIMUM ALLOWABLE VALUES BE SUBJECTED TO FURTHER INSPECTION TO ENSURE THAT THE ELEVATOR BALANCE PANEL SEAL COMPRESSION IS NOT EXCESSIVE.
In plain language (FlightFinder summary)
The FAA is urged to mandate that all Boeing 707 and 720 aircraft undergo a specific check of their elevator control forces during routine maintenance. If these checks reveal that friction levels are too high, the recommendation requires further inspection to determine if the seals on the elevator balance panels have compressed excessively. This process aims to ensure that control surface movements remain within safe operational limits.
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 - Unacceptable Action |
|---|---|
| Mode | Aviation |
| Closed | Dec 7, 1973 |
| NTSB number | LAX74AL019 |
| Addressees | FAA |
External links
NTSB safety recommendations are advisory; addressees are not legally required to adopt them. Source: NTSB CAROL (public domain).