Service difficulty report · Bypass Valve · Boeing 737401

Difficulty date
October 26, 2000
Submitted
December 18, 2000
Operation
Air carrier
Aircraft
N407US
Make and model
Boeing 737401
Aircraft serial
23877
Part
Bypass Valve
Part number
AV13J5144
Condition
Faulty
Location
Hyd System
Part time
35,201 hours
Stage of operation
AP
How discovered
O
Nature of condition
F
Precautionary procedure
L

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

What was found

BTV - FLT 1567 - ON APPROACH INTO BTV, THE FLAPS TO EXTEND AS THEY WOULD NOT MOVE FROM 5 DEGREES. MOVING FLAP LEVER UP OR DOWN WOULD NOT MOVE FLAPS. CREW WAS ABLE TO EXTEND FLAPS TO 15 DEGREES USING ALTERNATE FLAP PROCEDURE. FLIGHT CIRCLED BTV TO ALLOW CREW TIME IN DETERMINING ALLOWABLE WEIGHT FOR RUNWAY. FLIGHT LANDED WITHOUT FURTHER INCIDENT. NO EMERGENCY WAS DECLARED. MAINTENANCE FOUND THE TRAILING EDGE FLAPS HYDRAULIC BYPASS VALVE POPPING CIRCUIT BREAKER. REMOVED AND REPLACED HYDRAULIC BYPASS VALVE PER MM 27-51-82. OPERATIONAL CHECK AND LEAK CHECK GOOD. (M)