Service difficulty report · Lifter · Beech 58

Difficulty date
January 26, 2005
Submitted
February 15, 2006
Operation
General aviation
Aircraft
N584LL
Make and model
Beech 58
Aircraft serial
TH1931
Engine
Cont IO550C
Part
Lifter
Condition
Spalled
Location
Engine
Part time
509 hours
Stage of operation
NR
How discovered
9
Nature of condition
O
Precautionary procedure
O

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

What was found

METAL FOUND IN OIL FILTER DURING INSP WAS LATER DETERMINED TO BE FROM FAILED LIFTERS. CONDITION WAS STARTING TO DAMAGE CAM LOBES. SID 05-1 STATES THAT MINOR IMPERFECTIONS CAN (HEAL OVER) BUT WE HAVE NOT FOUND THIS TO BE CASE, JUST OPPOSITE IS TRUE. ONCE LIFTER BEGINS TO SPALL IT CREATES A (CHEESE GRATER) EFFECT BETWEEN CAM AND LIFTER. W/O PROPER METALLURGICAL LAB, CAUSE CANNOT BE DETERMINED. SPECULATED THAT MATERIAL IS EITHER IMPROPERLY HEAT TREATED OR SUBSTANDARD MATERIAL IS USED. TO PREVENT THIS FROM RECURRING MFG SHOULD INSPECT ALL LIFTER BODIES BEFORE INSTALLATION FOR GRANULAR DEFECTS OF METAL. THIS CAN BE ACCOMPLISHED USING X-RAY EXAM, NDT WHICH WOULD INCLUDE USE OF A SPECIAL MICROSCOPE. (K)

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