Service difficulty report · Hydraulic Line · Boeing 7379

Difficulty date
November 1, 2025
Submitted
November 4, 2025
Operation
Air carrier
Aircraft
N37504
Make and model
Boeing 7379
Aircraft serial
43435
Aircraft time
18,291 hours, 6,075 cycles
Part
Hydraulic Line
Part number
272A485126
Condition
Leaking
Location
Zone 300
Stage of operation
CL
How discovered
O
Nature of condition
J
Precautionary procedure
A

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

What was found

LOSS OF SYSTEM B HYDRALLICS NO EVIDENCE OF EXTERNAL LEAKAGE NOTED. HYD SYS B RESERVOIR NEAR EMPTY. ATTEMPTED TO SERVICE AND NO RAISE IN QTY INDICATION. SUSPECT INTERNAL LEAK AT HEAT EXCHANGER. MOVING TO BASE FOR MORE T/S SERVICED 'B' HYDRAULIC RESERVOIR TO FULL REF MM 12-12-00-610-801. DURING EXTERNAL INSPECTION FOUND HYDRAULIC LEAK IN HORIZONTAL STAB COMPARTMENT STREAMING FROM PIN HOLE IN HYDRAULIC LINE, FOUND 'B' PRESSURE RUDDER TUBE AT SECT 1088 LEAKING, REPLACED PRESSURE LINE AS REQUIRED REF IPC 29-11-52-14A, LEAK CHECK GOOD. CLEANED HYDRAULIC FLUID FROM HORIZONTAL STAB COMPARTMENT AND EXTERNAL SURFACES.

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