Service difficulty report · Seal

Difficulty date
January 6, 1999
Submitted
March 26, 2000
Operation
General aviation
Engine
Allsn AE3007A
Part
Seal
Part number
23055521
Condition
Worn
Location
Engine
Part time
1,785 hours
Stage of operation
IN
Nature of condition
A
Precautionary procedure
E

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

What was found

(CAN) ENGINE WAS HARD TO START, WITH A BALL OF FIRE OUT OF THE TAILPIPE AND RAPID RISE IN ITT. BORESCOPE INSPECTION REVEALED HP TURBINE BLADE DAMAGE AT THE TIPS. DURING DISASSEMBLY, THE COMBUSTION OUTER SEAL RING ASSEMBLY REAR FLANGE WAS FOUND SEPARATED FROM THE REMAINDER OF THE SEAL AND WAS IN TWO HALVES APPROXIMATELY 180 DEGREES EACH. A 0.157 INCH DIAMETER BALL BEARING LIKE ASSEMBLY WAS ALSO FOUND DURING REMOVAL OF THE HP TURBINE 1ST STAGE VANE AND SUPPORT ASSEMBLY. THIS PIECE WAS FOUND RESTING ON THE FRONT LIP OF THE COMBUSTION LINER OUTER SEAL RING. THE BALL BEARING LIKE PART APPEARS FOREIGN TO THE ENG. THE INVESTIGATION CONTINUES AND A FURTHER REPORT WILL FOLLOW. PART TC: 1,417.