Service difficulty report · Shroud · Dhav DHC8314

Difficulty date
January 22, 2015
Submitted
March 12, 2015
Operation
General aviation
Make and model
Dhav DHC8314
Aircraft time
44,923 hours
Engine
Pwa PW123
Part
Shroud
Part number
3039186CL
Condition
Damaged
Location
Engine
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

(CAN) ENGINE WAS RETURNED TO THE SHOP DUE TO DETERIORATED CONDITION OF THE LP SHROUD SEGMENTS DISCOVERED DURING A SCHEDULED BORESCOPE INPSECTION IN THE FIELD. THE LP SHROUD SEGMENTS WERE SUBSEQUENTLY REMOVED FROM THE ENGINE AND INSPECTED AT PIECE-PART LEVEL. THE THERMAL SPRAY COATING ON QTY 12 SEGMENTS WAS FOUND TO BE DELAMINATING TO VARYING EXTENTS FROM THE BASE METAL. THIS RESULTED IN RUBS BY LP TURBINE BLADE TIPS, RESULTING IN DAMAGE TO THE BLADES. REFER TO PHOTOS 1-3 ATTACHED FOR EXAMPLES OF LIFTING COATING. THE ENGINE WAS REPAIRED AND RETURNED TO SERVICE, HOWEVER AFTER ONLY 95.8 FLIGHT HOURS, IT WAS FOUND TO HAVE 2 HP SHROUD SEGMENTS THAT WERE ALSO DELAMINATING, AND SHOWING EVIDENCE OF CONTACT WITH THE HP BLADES. REFER TO PHOTOGRAPH 4 ATTACHED. (TC# 20150126005)