Service difficulty report · Mast · Bolkms BO105C

Difficulty date
July 14, 2000
Submitted
August 30, 2000
Operation
General aviation
Make and model
Bolkms BO105C
Aircraft time
4,947 hours
Engine
Allsn 250C20B
Part
Mast
Part number
4619305032M
Condition
Failed
Location
Main Rotor
Part time
6,061 hours
Component
Main Trans · 3638001009
Stage of operation
TO
How discovered
V
Nature of condition
J
Precautionary procedure
D

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

What was found

(CAN) EVENT: DURING PILOT TRAINING OFF-LEVEL LANDING BEING CONDUCTED; A/C LANDED ON SLOPE WITH RT SKID LOW. PILOTS WERE CHECKING THEIR RESPECTIVE SIDES OF A/C AND A/C MOVED ON SLOPE. PILOT APPLIED CYCLIC INPUT WHEN THE A/C SLIPPED. WHEN A/C LIFTED INTO HOVER,TRAINING PILOT NOTICED MAST MOMENT IND. LIGHT ON STEADY, AND A/C RETURNED TO BASE. MAINT ACTION: MAINT MANUAL CHECKED FOR PROCEDURES WHEN MAST MOMENT LIMITS EXCEEDED. MAIN ROTOR STUDS WERE CHECKED FOR LOSS OF TORQUE. RESULTS OF TORQUE INSP REVEALED THAT ALL 12 NUTS HAD LESS THAN MIN 140 NEWTON METERS OF TORQUE 4 OF 12 NUTS MOVED APPROXIMATELY 1/4 OF FLAT TO BRING THEM UP TO TORQUE.