Service difficulty report · Crankcase · Grumav G21A

Difficulty date
August 12, 1998
Submitted
March 26, 2000
Operation
General aviation
Make and model
Grumav G21A
Engine
Pwa R985AN14B
Part
Crankcase
Part number
3508
Condition
Cracked
Location
Engine
Stage of operation
IN
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) REMOVAL OF NR 5 CYLINDER, DUE TO LOW COMPRESSION, REVEALED A CIRCUMFERENTIAL CRACK IN THE FORWARD FACE OF THE FORWARD CRANKCASE HALF. NUMEROUS CRYSTALLINE STRUCTURED CHIPS WERE FOUND IN THE MAIN OIL SCREEN. THE AMOUNT OF MATERIAL WAS NOT UNUSUAL, BUT THE TYPE OF MATERIAL WAS. THE ENGINE HAD DEVELOPED AN OIL LEAK THAT WAS TRACED TO THE CRACK IN THE FORWARD CASE. THE CRACK WAS EXTENSIVE ENOUGH TO CONSIDER ENGINE FAILURE IMMINENT.