Service difficulty report · Rod · Aerosp ATR42300

Difficulty date
July 19, 2019
Submitted
August 17, 2020
Operation
General aviation
Make and model
Aerosp ATR42300
Aircraft time
49,019 hours
Propeller
Hamstd 14SF5
Part
Rod
Part number
S00021004100100
Condition
Damaged
Location
A/C Pack
Stage of operation
NR
How discovered
9
Nature of condition
O
Precautionary procedure
O

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

What was found

(CAN) DESCRIPTION:DURING CLEAR TO CLOSE PROCEDURE UNDER W/O 33428361 TASK GEN-05-00-400-0002 IT WAS NOTICED THE BLEED AIR PRESSURE REGULATOR ON THE #2 ENGINE WAS VERY CLOSE TO THE NACELLE PANEL. WHEN THE VALVE WAS ROTATED TO CLEAR, IT WAS NOTICED THE CLAMP FOR THE VALVE WAS CHAFING INTO THE ENGINE MOUNT. SUBSEQUENT INVESTIGATION REVEALED THE ROD ASSEMBLY HOLDING THE VALVE IN POSITION HAD TWO JAM NUTS FOR THE TURNBARREL WHICH WERE NOT TIGHT ALLOWING THE ROD TO EXTEND OVER TIME ALLOWING THE VALVE TO CONTACT THE FRAME TUBE. BOTH OF THE LOCK WASHERS WERE IN PLACE AND CRIMPED CORRECTLY BUT IT WAS NOTED THE TWO DIMPLES ON THE LOCK WASHER WHICH FIT INTO THE LOCKING GROOVES ON THE TURNBARREL WERE FLATTENED. SPECULATION IS THE JAM NUT WAS TIGHTENED WITH THE DIMPLES NOT IN THE CORRECT ORIENTATION DEFEATING THE LOCKING FEATURE ALLOWING THE NUT TO TURN. CORRECTIVE ACTION: THE ROD ASSEMBLY IN QUESTION HAS BEEN ORDERED AND THE DAMAGED ENGINE MOUNT IS CURRENTLY BEING REPLACED ON W/O 33428361 NR 00056. (TC# 20190725014)

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