Service difficulty report · Mount · Dhav DHC8301

Difficulty date
April 6, 2011
Submitted
September 14, 2015
Operation
General aviation
Make and model
Dhav DHC8301
Aircraft time
46,730 hours
Engine
Pwa PW123
Propeller
Hamstd 14SF*
Part
Mount
Part number
LM43183V
Condition
Failed
Location
Engine
Stage of operation
NR
How discovered
O
Nature of condition
E
Precautionary procedure
O

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

What was found

(CAN) DURING THE ACCEPTANCE FLIGHT OF ACFT 313, A VIBE WAS DETECTED ON NR 1 ENG & PROP. INVESTIGATION BY MTCE PERSONNEL, POST FLIGHT QUICKLY REVEALED THAT THE NR 1 ENG TOP MOUNT HAD FAILED DUE TO DISBOND. THE TOP MOUNT PN LM-431-83-V, SN LK0014 WAS INSTALLED DURING A BLOCK CHECK ENG CHANGE AS PART OF AN ENG MOUNT KIT PN LM-431F. THE INFORMATION AT PRESENT IS, THIS TOP MOUNT WAS A SERVICEABLE MOUNT THAT WAS SUPPLIED WITH THE ENG THAT WAS BEING INSTALLED. THE LIMITS FOR DISBOND ARE SPECIFIED IN THE ORD CORPORATION 71-20-18 PG. 505, BASICALLY GREATER THAN ½ INCH DEPTH OR MORE THAN 1 INCH IN LENGTH IS UNACCEPTABLE. THIS PARTICULAR MOUNT FAILS BOTH PARAMETERS. EVEN WITH THE MOUNT REMOVED FROM THE ACFT, UNLOADED, THE DAMAGE TO IT IS EASILY IDENTIFIED. IT IS SAGGED ABOUT 3/16 OF AN INCH MORE, THAN A NEW ONE. A POINT OF INTEREST IS THE VIN IN THE PN INDICATES THAT IT IS REMANUFACTUED VS NEW.