Service difficulty report · Control Valve · Lear 35A

Difficulty date
August 7, 2019
Submitted
August 17, 2020
Operation
General aviation
Make and model
Lear 35A
Aircraft time
17,993 hours
Engine
Garrtt TFE73122B
Part
Control Valve
Part number
31341
Condition
Failed
Location
Thrust Reverser
Component
Thrust Reverser · Lear
Component part number
451000052
Stage of operation
NR
How discovered
O
Nature of condition
F
Precautionary procedure
E

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

What was found

(CAN) PILOT REPORTED: IN CRUISE THE RH T/R UNLOCK LIGHT ILLUMINATED. AT TOP OF DECENT PUSHED THE T/R TEST AND NOTED YAW TO THE RIGHT THAT FELT LIKE RH T/R DEPLOYMENT. PULLED THE RH ENGINE TO IDLE STOPPING THE YAW. DESCENDED, SLOWED TO 200 KIAS AND RAN THE ABNORMAL CHECKLIST FOR INADVERTENT T/R DEPLOYMENT. THE RH T/R UNLOCK LIGHT REMAINED ILLUMINATED, SO AS PER THE CHECKLIST THE RH ENGINE WAS SHUT DOWN. MAINTENANCE FINDINGS: ON INSPECTION MAINTENANCE FOUND RH T/R PNEUMATIC LATCHES UNLOCKED AND THE RH T/R TRANSLATING STRUCTURE SITTING SLIGHTLY FURTHER BACK (1/16 ) THAN THE LH T/R WHICH WAS LOCKED. FOUND THE RH T/R PNEUMATIC LATCH CONTROL VALVE WAS ALLOWING AIR TO PASS TO THE PNEUMATIC LATCHED EVEN WHEN STOW OR EMERGENCY STOW WAS SELECTED. ALLOWING THIS CONSTANT AIRFLOW WAS CAUSING THE PNEUMATIC LATCHES TO BE IN A CONSTANTLY UNLOCKED STATE AND ALLOWING THE RH T/R TRANSLATING STRUCTURE TO SLOWLY MIGRATE AFT IN FLIGHT (TC# 20190808006)

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