AD 51-04-02
Applicability
| Type | Manufacturer | Model | Details |
|---|---|---|---|
| engine | Warner Engine Company, LLC | Scarab Jr. Series 40 | WARNER Model All Engines Except Those With the Letter "A" |
| engine | Warner Engine Company, LLC | Scarab Jr. Series 50 | WARNER Model All Engines Except Those With the Letter "A" |
| engine | Warner Engine Company, LLC | Scarab Series 28 | WARNER Model All Engines Except Those With the Letter "A" |
| engine | Warner Engine Company, LLC | Scarab Series 29 | WARNER Model All Engines Except Those With the Letter "A" |
| engine | Warner Engine Company, LLC | Scarab Series 30 | WARNER Model All Engines Except Those With the Letter "A" |
| engine | Warner Engine Company, LLC | Scarab Series 40 | WARNER Model All Engines Except Those With the Letter "A" |
| engine | Warner Engine Company, LLC | Scarab Series 50 | WARNER Model All Engines Except Those With the Letter "A" |
| engine | Warner Engine Company, LLC | Super Scarab Series 165 | WARNER Model All Engines Except Those With the Letter "A" |
| engine | Warner Engine Company, LLC | Super Scarab Series 165-B | WARNER Model All Engines Except Those With the Letter "A" |
| engine | Warner Engine Company, LLC | Super Scarab Series 165-D | WARNER Model All Engines Except Those With the Letter "A" |
Unsafe Condition
Failure of the 5/16-inch cylinder holddown studs P/N S506, which can result from stretching due to loose nuts leading to fatigue failure.
AI-generated summary from the source AD text. Verify against the official source before acting.
Required Actions
Inspect cylinder holddown nuts for torque between 180 and 200 inch-pounds, replace broken studs for the affected cylinder, and replace all studs if nuts are loose. Alternatively, replace 5/16-inch studs S506 and nuts N-511 with 3/8-inch stud S-911 and nut N-910, install an 'O' type ring gasket, and stamp 'A' on the engine nameplate.
AI-generated summary from the source AD text. Verify against the official source before acting.
Compliance Time
As soon as possible but not later than April 1, 1951 and at each 100 hours of operation thereafter.
AI-generated summary from the source AD text. Verify against the official source before acting.
Affected Aircraft
Warner Engine Company, LLC engines: Scarab Jr. Series 40, Scarab Jr. Series 50, Scarab Series 28, Scarab Series 29, Scarab Series 30, and others except those with the letter 'A' stamped after the serial number on the engine nameplate.
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.