AD 49-52-01
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Lockheed Aircraft Corporation | 149-46 | LOCKHEED Models 49, 149, 649, and 749 Aircraft |
| aircraft | Lockheed Aircraft Corporation | 49-46 | LOCKHEED Models 49, 149, 649, and 749 Aircraft |
| aircraft | Lockheed Aircraft Corporation | 649-79 | LOCKHEED Models 49, 149, 649, and 749 Aircraft |
| aircraft | Lockheed Aircraft Corporation | 649A-79 | LOCKHEED Models 49, 149, 649, and 749 Aircraft |
| aircraft | Lockheed Aircraft Corporation | 749-79 | LOCKHEED Models 49, 149, 649, and 749 Aircraft |
| aircraft | Lockheed Aircraft Corporation | 749A-79 | LOCKHEED Models 49, 149, 649, and 749 Aircraft |
Unsafe Condition
Malfunctioning of the elevator booster system causing longitudinal hunting and potential passenger injury due to frozen moisture in the shifter mechanism, and inability to actuate the shifter mechanism.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Rework and lubricate booster control valves by drilling drain holes, reaming bushings, replacing plugs, packing with grease, and reidentifying parts. Rework elevator shifter latches by removing hook ends, ensuring proper rigging. Chamfer feel lever bolt holes in elevator walking beam assembly. Revise flight manuals with specified revisions by July 15, 1949.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
At or prior to next engine overhaul period (for booster unit rework and lubrication), at or prior to next No. 3 inspection (for shifter latches), as soon as practicable but not later than next engine change (for power levers), and not later than July 15, 1949 (for flight manual revisions).
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Lockheed Models 49, 149, 649, and 749 Aircraft, all serial numbers.
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
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