Service difficulty report · Relay · Boeing 777222

Difficulty date
May 9, 2026
Submitted
May 11, 2026
Operation
Air carrier
Aircraft
N794UA
Make and model
Boeing 777222
Aircraft serial
26953
Aircraft time
114,850 hours, 15,000 cycles
Part
Relay
Condition
Faulted
Location
Zone 900
Stage of operation
NR
How discovered
O
Nature of condition
B
Precautionary procedure
O

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

What was found

AHM DETECTED MMSG {21-11121 *RELAY (CHILLER BOOST FAN) IN P210 IS NOT IN COMMANDED POSITION* AFTER WORK WAS ACCOMPLISHED DUE TO A SMOKE ODOR CONDITION. REF FIM 21-26- 804 TO PERFORM STEPS G. (1)-(2). ENSURE TO REPORT ON C/B 21307 STATE AND WIRE CONDITION. REPLACE C/B AND OR RELAY AS REQ'D. CARRIED BY ELB REF FIM 21-26 TASK 804 REPLACE THE CHILLER BOOST FAN RELAY, K21264, IN THE P210 PANEL PERFORMED TEST 21 EVIREMENTAL SYSTEM PASSED. CONFIRMED CB AND CHILLER BOOST FAN OPS CHECK OK.