Service difficulty report · Retaining Ring

Difficulty date
April 30, 2004
Submitted
July 22, 2004
Operation
General aviation
Engine
Pwa PT6A114A
Part
Retaining Ring
Part number
3020159
Condition
Collapsed
Location
Turbine Shroud
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) THE HOT SECTION WAS GIVEN A SCHEDULED BORESCOPE INSPECTION. CT SHROUD SEGMENTS HAD SHIFTED AXIALLY. DISMANTLE SHOWED THE RETAINING RING TO HAVE DISTORTED AND BECOME DISLOCATED. THIS PROBLEM HAS BEEN DOCUMENTED ON OTHER ENGINES. MFG HAS ISSUED P/N 3110741-02 RETAINING RING ON SB 13121 (60A, 61, 62, 65 SERIES) AND SB 3248 (41/42, 45 SERIES) TO PREVENT THE COLLAPSE OF THE RETAINING RING. THE LATTER SB HAS NOT BEEN ISSUED ON SMALLER ENGINE MODELS SUCH AS THE 114A ENGINE MODEL TO ALLOW THE MORE ROBUST RETAINING RING TO BE USED.