AD 46-13-03
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| aircraft | Lockheed Aircraft Corporation | 18 | LOCKHEED Model 18 Aircraft |
Unsafe Condition
Hopper type oil tanks may have inadequate support at the sump and insufficient oil reservoir for propeller feathering, leading to oil starvation and engine failure.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect oil tanks to determine if they are hopper type. If retained, install a propeller feathering reserve oil tank (P/N 174399) and rework the hopper assembly with support assembly (P/N 174321). If removed, replace with conventional tank (P/N 73662) and install separate feathering line. Revise standpipe length or install new standpipe assembly as applicable.
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Compliance Time
before next 10 hours of operation
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Affected Aircraft
Lockheed Model 18 Aircraft, Serial Numbers 2294 and up (except 2359, 2403, 2464, 2465) for some actions; all Series 18 except Models 18-07 and 18-40 with Serial Numbers 2293 and below, 2359, 2403, 2464, and 2465 for standpipe revisions.
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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