Bellanca 7ECA Shorting Ammeter Wire “While in flight,” states a technician, “the pilot reported he could smell something burning-he landed as soon as was practical. Investigation revealed the wire from the alternator to the ammeter (p/n 112) had shorted against the firewall….” “Wires 112, 114, the master relay, starter relay, voltage regulator and alternator were all replaced.” 288
Leaks and Shorts
After sitting idle on a ramp for at least 10 months, the airplane underwent maintenance. A strong fuel odor was observed in the cabin; an exterior inspection failed to detect anomalies. The odor subsided. Once the engines were started and the fuel selector placed in crossfeed, the odor returned. After removing the floorboards, a heater duct running perpendicular to the crossfeed lines was observed to be in contact, causing corrosion. Pinhole leaks had developed in both lines, p/n 5300108-53 and -54.
Key Takeaways:
- A Bellanca 7ECA experienced an electrical short circuit from an ammeter wire rubbing against the firewall, causing a burning smell in flight.
- Multiple fuel system issues were reported, including corroded fuel lines on a Cessna 340A caused by contact with a heater duct, and failed polymer floats in two different carburetors (Facet and Precision Airmotive) leading to fuel leaks and erratic engine performance, with recommendations for recalls.
- A Lamar PM2401 starter suffered an internal mechanical failure when a segment of its commutator detached, destroying the brushes.
Key takeaways sponsored by Aviator Pro | Start Your Training ->
See a mistake? Contact us.
