AD 77-16-11
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | The Boeing Company | 707-300 Series | BOEING Model 707-300/400/300B/300C Series Airplanes |
| aircraft | The Boeing Company | 707-300B Series | BOEING Model 707-300/400/300B/300C Series Airplanes |
| aircraft | The Boeing Company | 707-300C Series | BOEING Model 707-300/400/300B/300C Series Airplanes |
| aircraft | The Boeing Company | 707-400 Series | BOEING Model 707-300/400/300B/300C Series Airplanes |
Unsafe Condition
Cracks at the horizontal stabilizer rear spar upper chord from the side of the body to horizontal stabilizer station 92.55.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect the horizontal stabilizer rear spar upper chord using low or high frequency eddy current inspection per Boeing Alert Service Bulletin No. 3313, Revision 2. Reinspect at intervals not exceeding 375 landings if cracks are found in the forward flange. Replace the chord if cracks penetrate the upper radius, or use an approved method. Report all cracks to the FAA Northwest Region with specified details.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
Within the next 175 landings after the effective date of this AD, unless accomplished within the previous 200 landings prior to the effective date, and thereafter at intervals not to exceed 375 landings.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Boeing Model 707-300/400/300B/300C Series airplanes with more than 8,000 landings.
AI-generated summary from the source AD text. Verify against the official source before acting.
Source: Official FAA Source ↗
Retrieved: Apr 8, 2026
Rights: U.S. Government Public Domain
This site is not affiliated with or endorsed by the FAA. Always verify with official sources.