Service difficulty report · Actuator · Boeing 737990ER

Difficulty date
July 21, 2017
Submitted
July 26, 2017
Operation
Air carrier
Aircraft
N457AS
Make and model
Boeing 737990ER
Aircraft serial
36355
Aircraft time
13,874 hours, 4,588 cycles
Part
Actuator
Part number
676000141
Part serial
67600014862
Condition
Failed
Location
Ram Air
Part time
12,626 hours, 4,173 cycles
Stage of operation
TX
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

RIGHT RAM AIR DEFLECTOR DOOR NOT FULLY OPEN ON GROUND. ACFT GROUNDED. FOUND THE RT RAM AIR INLET DOOR NOT LOCKING. BITE CHECKED WITH NO FAULTS IAW AMM 21-61-00-700-806-002. DOOR STILL NOT LOCKING OPEN. PERFORMED RAM AIR SYSTEM OPS TEST IAW AMM 21-51-00-730-801. UNABLE TO DUPLICATE DEFECT OR PREVIOUS FINDINGS BUT NOTED THAT INLET SRADA ACTUATOR ROD DID NOT ALWAYS RETURN TO SAME POSITION AT END OF EACH TEST. REMOVED, REPLACED, ADJUSTED, AND TESTED INLET SRADA ACTUATOR IAW AMM 21-51-21-000-801 AND 21-51-21-400-801. ACTUATOR INITIALLY OPERATED NORMALLY & PASSED PACK/ZONE TEMP CONTROLLER BITE BUT DURING RAM AIR SYSTEM OPS TEST IAW AMM 21-51-00-730-801, INLET AND EXHAUST SRADA ACTUATORS SHOWED RAM AIR SENSOR FAULT AND SAME FAULT OCCURS DURING PACK OPERATION. REMOVED, REPLACED, ADJUSTED, AND TESTED RIGHT PACK INLET SRADA ACTUATOR IAW AMM 21-51-21-000-801 & 21-51-21-400-801. OPS NORMAL. PERFORMED RAM AIR SYSTEM OPS TEST IAW AMM 21-51-00-730-801 MULTIPLE TIMES, OPERATED PACK, AND PERFORMED PACK/ZONE TEMPERATURE CONTROLLER BITE IAW AMM 21-61-00-700-806-002 MULTIPLE TIMES.