Service difficulty report · Ballscrew · Dhav DHC8102

Difficulty date
July 10, 2004
Submitted
January 5, 2005
Operation
General aviation
Make and model
Dhav DHC8102
Aircraft time
12,349 hours
Engine
Pwa PW120A
Propeller
Hamstd 14SF7
Part
Ballscrew
Part number
734181D
Part serial
0160
Condition
Damaged
Location
Te Flaps
Stage of operation
IN
How discovered
9
Nature of condition
O
Precautionary procedure
K

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

What was found

WHILE PERFORMING THE REPEAT INSPECTION REQUIREMENTS OF CF-2002-26R1 THE NR 4 RT BALLSCREW ACTUATOR WAS FOUND TO HAVE A TOTAL FREEPLAY BACKLASH OF .192 INCH. THE LAST INSPECTION HAD BEEN DONE 997 HRS AND 863 CYC PREVIOUSLY AND AT THAT TIME WAS .030 INCH. THE ACTUATOR WAS REPLACED WITH AN OVERHAULED UNIT FROM HAMILTON SUNDSTRAND. THE AD REQUIREMENTS INVOLVE THE MEASURING OF THE BACKLASH BETWEEN THE SCREW JACK ROD AND THE NUT WHICH WAS STILL FOUND TO BE WITHIN SERVICEABLE LIMITS HOWEVER THE TOTAL FREEPLAY BACKLASH WHICH COMPRISES OF THIS BACKLASH MEASUREMENT AS WELL AS THE FREEPLAY BETWEEN THE BALLSCREW NUT AND THE ACTUATOR BODY WAS FOUND TO BE EXCESSIVE. THE INSERVICE LIMIT FOR THIS MEASUREMENT IS .057 INCH.