Service difficulty report · Valve · Boeing 737890

Difficulty date
March 9, 2023
Submitted
March 13, 2023
Operation
Air carrier
Aircraft
N532AS
Make and model
Boeing 737890
Aircraft serial
36346
Aircraft time
45,788 hours, 13,523 cycles
Part
Valve
Part number
3989085
Part serial
25515
Condition
Uncontrollable
Location
Right Ecs Bay
Part time
24,892 hours, 7,896 cycles
Stage of operation
IN
How discovered
V
Nature of condition
O
Precautionary procedure
K

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

What was found

HISTORY OF R/H PACK TEMP UNCONTROLLABLE. GROUNDED - YES. PERFORMED BITE TEST OF RH PACK TEMP CONTROLLER (M1443) AND TORQUE CHECK OF THE RH PACK ACM REF B737-800 FIM 21-62 TASK 849. BITE TEST RESULTED IN A "THIS PACK -TCV" LIGHT ON BIT AND PREV FLT. DISPLAYED GREEN LIGHT ON VERIFY. TORQUE CHECK OF THE ACM PASSED. LEAK TEST OF ACM AND SENSE LINES PASSED. STCV CHECK NO DEFECTS FOUND. BOTH MIX MANIFOLD SENSORS CLEANED AND RESISTANCE CHECKED. AFTER REINSTALLATION AND BITE CHECK, RH P2 TC FAILS FOR TCV AND WILL NOT RESET. REPLACED R/H TCV REF AMM 21-51-10. R/H TCV OPS CHECK GOOD PER AMM 21-61-00 AND LEAK CHECK GOOD PER AMM 21-51-10.