A-23-008
NTSB Safety Recommendation — Aviation
Recommendation text
TO VIKING AIR: Revise the DHC-3 aircraft maintenance manual to include inspection and overhaul procedures for the horizontal stabilizer actuator that specify how many holes can be drilled into the clamp nut and how to determine if the holes are airworthy, a proper torque value for installing the clamp nut, and how to install the lock ring and verify that it is properly seated and functions as intended.
In plain language (FlightFinder summary)
Viking Air is directed to revise the DHC-3 aircraft maintenance manual to add detailed procedures for the horizontal stabilizer actuator, including inspection and overhaul steps for the clamp nut, proper torque values, and instructions for installing and verifying the lock ring.
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 | Apr 15, 2026 |
| NTSB number | DCA22MA193 |
| Addressees | De Havilland Aircraft of Canada Limited (formerly Viking Air) |
External links
NTSB safety recommendations are advisory; addressees are not legally required to adopt them. Source: NTSB CAROL (public domain).