Service difficulty report · Contactor · Boeing 767322

Difficulty date
September 25, 2025
Submitted
September 29, 2025
Operation
Air carrier
Aircraft
N664UA
Make and model
Boeing 767322
Aircraft serial
29236
Aircraft time
94,044 hours, 19,604 cycles
Part
Contactor
Part number
A703CD
Condition
Missing
Location
Apu
Stage of operation
IN
How discovered
C
Nature of condition
L
Precautionary procedure
K

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

What was found

APU CRANK CONTACTOR U/S ON FIT. APU CRANK CONTACTOR FOUND TO BE MISSING END STOP CAUSING CONTACTS TO BE MADE, NOTICED AFTER UNCOMMANDED APU START ON APU BATTERY CONNECTION. DEFECTIVE ON FIT APU CONTACTOR REPLACED AS PER AMM TASK 49-41-05-404-005. APU CRANK CONTACTOR WAS CLOSED ON FIT UNABLE TO NOTICE THIS, WHEN APU BATTERY CONNECTED LARGE SPARKS PRESENT & APU BEGAN TO TURN UNCOMMANDED. ON OPENING OF COMPONENT AN INTERNAL STOP WAS FOUND TO NOT BE FITTED ALLOWING THE SPRING OF THE RELAY TO PUSH THE CONTACTORS TOGETHER CAUSING CIRCUIT TO BE COMPLETE RISKING ELECTRICUTION & FIRE AS WELL AS CAUSING UNCOMMANDED ENGAGMENT OF APUNSTARTER.