Service difficulty report · Precooler · Boeing 737890

Difficulty date
February 22, 2009
Submitted
February 24, 2009
Operation
Air carrier
Aircraft
N587AS
Make and model
Boeing 737890
Aircraft serial
35684
Aircraft time
5,288 hours, 1,526 cycles
Part
Precooler
Part number
32895625
Part serial
6682
Condition
Failed
Location
Bleed Air Sys
Part time
27,039 hours, 12,222 cycles
Stage of operation
CR
How discovered
O
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

IN CRUISE FLIGHT AT 37000 RIGHT DUCT PRESSURE IS 25 PSI LEFT DUCT PRESSURE 44 PSI. RIGHT DUCT PRESSURE VARIES BETWEEN 21 PSI AND 44 PSI. ACCOMPLISHED FIM TASK 36 10 00 810 804 STEP 21F 34G, PERFORMED NR 2 ENG BLEED AIR SYSTEM HEALTH CHECK. FOUND PRECOOLER BAD, FAILED TO OPEN. REMOVED AND REPLACED PRECOOLER VALVE REF AMM 36 12 01. FOUND PRSOV VALVE FAILED TO OPEN AT 10 PSI. REMOVED AND REPLACED PRSOV REF AMM 36 11 04. LEAK CHECKED ALL SENSE LINES, NO LEAKS FOUND. HIGH STAGE VALVE FAILED TO OPEN WITH 10 PSI . REMOVED AND REPLACED HIGH STAGE VALVE REF AMM 36 11 06. RE-PERFORMED FIM TASK 36 10 00, NO FAULTS NOTED. ACCOMPLISHED ENGINE BLEED AIR CROSSOVER OPS TEST, OPS CHECKED GOOD. REF AMM 36 11 00 710 801. ALL PART NUMBERS VERIFIED WITH SEAMC.