Service difficulty report · Switch · Cessna 120

Difficulty date
May 16, 2022
Submitted
May 17, 2022
Operation
Air carrier
Aircraft
N807QS
Make and model
Cessna 120
Aircraft serial
7000032
Aircraft time
1,617 hours, 939 cycles
Part
Switch
Condition
Intermittent
Stage of operation
TX
How discovered
C
Nature of condition
L
Precautionary procedure
O

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

CABIN EMERG LIGHT: EMERGENCY LIGHTING SYSTEM FAILS TO TEST PROPERLY ON PREFLIGHT. ALTHOUGH THEY INITIALLY ALL ILLUMINATE PROPERLY WHEN SELECTING THEM TO "ARM" WITH MAIN SHIP BATTERIES "OFF", THEY REMAIN ILLUMINATED ONCE MAIN SHIP BATTERIES ARE "ON" AND ALSO WITH APU RUNNING. ADDITIONALLY, WITH EMER LIGHTS SWITCH SELECTED "OFF", THEY ALL REMAIN ILLUMINATED. SUSPECT EITHER BAD SWITCH AND/OR RELAY. I DO NOT BELIEVE IT IS THE EMER BATTERIES THAT ARE FAULTY. // SIGNOFF// (GAINED ACCESS TO ANO RESET ALL 4 G-SWITCHES IN THE EMER LIGHT SYSTEM, 2 FWD AND 2 AFT TOP CHARGED EMER LIGHT BATTERIES. PERFORMED MULTIPLE OPS CHECKS OF THE EMER LIGHT SYSTEM AND ALL OPS CHECKS ARE GOOD AT THIS TIME. REF. CE-700 AMM 33-50-00.

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