Parts And Components


The following information is derived from the FAAs Service Difficulty Reports and Aviation Maintenance Alerts

Unison UREM40E
Defective Spark Plugs

During the installation and operational check of two new Unison/Slick magnetos-plus harness and eight spark plugs-to correct a hard starting discrepancy, the engine had a 200-300 RPM magneto drop on the left magneto.

Troubleshooting determined one of the eight new spark plugs (p/n UREM40E) was defective. Once the defective plug was replaced with a known good plug, the engines operational check was good.

Part Total Time: 0 hours.


Piper PA28-161
Broken Throttle Cable

The throttle cable (p/n 455-350) broke inside its housing. Frayed ends caught in the cable housing, resulting in the throttle becoming stuck in the full-open position. The pilot made a successful “dead-stick” landing.

Part Total Time: 9670.0 hours.


Precision Airmotive MA-3PA
Carburetor Contamination

A Cessna 152 pulled by a Lycoming O-235 developed carburetor problems. The pilot reported partial loss of power and executed a precautionary off-field landing-there was no damage to the aircraft. Teardown of the carburetor (model and p/n MA-3PA and 10-5267, respectively) revealed metal shavings in the accelerator pump circuit. It is suspected the metal particles originated from the accelerator pump stems rubbing on the housing.

Part Total Time: (unknown).


Continental IO550
Broken Through-Bolt

“This through-bolt is the replacement (bolt) installed August 2005 due to the original through-bolt also breaking at the same location (it managed 650 hours). It is ironic both bolts broke at the same location with identical break lines, the first with 650 hours since remanufacture and the replacement with 200 hours.”

Part Total Time: 200.0 hours.


Lone Star
DC Converter Failure

A new converter was installed per Lone Star Aviations instructions: the diagrams and installation was approved with a 337 (field approval). The converter failed in less than 10 seconds. Out of five converters, four in aircraft and one on the test bench, all have failed (p/n LS03-05002).

Part Total Time: 0.003 hours


Challenger K&N Air Filter
Missing Mesh Material

The wire mesh enclosing the cotton fiber material is tearing and exposing the filter material. Some of the wire mesh and filter material [was] missing and was presumed ingested by the engine. This filter eliminates the requirements set forth in AD 84-26-02 dealing with ingestion of paper air filters. The submitter states, “Judging by the results I have seen from this and other filters I have removed from service, these filters pose a greater risk of ingestion and (resultant) engine failure than paper filters.”

Part Total Time: 293.4 hours.



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