Switch Problems

Editorial Staff

Monday, October 25, 2021 at 10:38 AM ET

Verified

Key Takeaways:

Aircraft across various models experienced diverse switch malfunctions, including landing gear, landing lights, navigation lights, taxi lights, and cabin heater switches.
Symptoms ranged from flickering indicator lights and gear retraction failures to switches sticking, smoke, burning smells, and sparks, sometimes accompanied by tripped circuit breakers.
These issues were typically resolved by adjusting or replacing the faulty switch, often due to internal arcing, shorts, or burned terminals, underscoring the importance of switch reliability.

See a mistake? Contact us.

Beech 58 Baron

Nose Gear Switch Out Of Adjustment

During landing approach, the nose gear light flickered. Pilot recycled gear and received three-green, gear-down-and-locked indication, landing without incident. Maintenance found the nose gear down-and-locked indicator switch out of adjustment. Adjusted switch. Performed multiple landing gear retractions without a failure.

Part total time: Unknown

Beechcraft B300 King Air

Intermittent Landing Gear Switch

Landing gear would not retract, followed by gear-in-transit annunciation and the landing gear circuit breaker tripping. Circuit breaker was reset and gear handle was placed in down position. Landing was uneventful. Replaced landing gear handle selector switch per manufacturer’s recommendation.

Part total time: 2505.0 hours

Cessna 172P Skyhawk

Stuck Landing Light Switch

Landing light switch was stuck in “on” position. Switch replaced. Suspect internal arcing and welding of contacts. The overheating caused by the arcing can cause the switch body to melt, but did not in this case. No signs of heat damage of external switch surface were found.

Part total time: 746.0 hours

Cessna 208B Grand Caravan

Stuck Landing Light Switch

During initial climb, the captain smelled burning rubber and saw smoke coming from the left circuit breaker panel. The aircraft landed safely. The left landing light switch could not be switched to the off position but no CB was popped. The switch (p/n MS25306222) was replaced with a serviceable unit and checked okay.

Part total time: Unknown

Cessna 402C Businessliner

Burned Nav Light Switch

When nav light switch actuated, smoke came out of switch. Inspection found the nav light switch burned. Maintenance repaired wiring in left wing tip and replaced nav light switch with no further defects noted.

Part total time: Unknown

Piper PA-31-350 Navajo Chieftain

Shorted Taxi Light Switch

Sparks and smoke observed coming from overhead panel. Emergency declared. Found taxi light switch shorted. Taxi and landing light switches replaced. No further issues.

Part total time: Unknown

Piper PA-31-350 Navajo Chieftain

Burned Cabin Heater System Switch

Upon landing, pilot noticed smoke in the cabin. Inspection determined the blower switch for the cabin heat system had a burned terminal. Replaced the defective switch and ring terminal.

Part total time: Unknown