Service difficulty report · Combustion Liner · Dhav DHC3

Difficulty date
March 19, 2005
Submitted
April 1, 2005
Operation
General aviation
Make and model
Dhav DHC3
Aircraft time
27,692 hours
Engine
Pwa PT6A34
Propeller
Hartzl HCB3TN3
Part
Combustion Liner
Part number
310926302
Condition
Cracked
Location
Engine
Stage of operation
IN
How discovered
B
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) 3 INCH BURN THROUGH INNER LINER IN COMBUSTION AREA. ONE SMALL PINHOLE THROUGH PRIMARY SHROUD OR CAP. THE CAP ON THE AFT FACE OF THE UNIT HAD CRACKED ABOUT 120 DEGREES AROUND THE CIRCUMFERENCE. THE BURN THROUGH WAS VISIBLE WITH THE BOROSCOPE INSPECTION HOWEVER THE CRACK ON THE AFT FACE WAS ONLY VISIBLE WITH THE LED REMOVED. SUSPECT THAT A BAD FUEL NOZZLE WAS THE CAUSE OF THE BURN THROUGH. HOT GASES ENTERING THE VOID BETWEEN THE PRIMARY SHROUD/CAP THROUGH THE BURN HOLE IN THE INNER LINER MAY HAVE BEEN RESPONSIBLE FOR THE CRACKING.