BHT-407-MM-1
5-00-00
7 NOV 2006 Rev. 23
Page 65
Chapter 63
TRANSMISSION AND MAST ASSEMBLY
1.
If the main rotor mast broke in two during a main rotor
sudden stoppage “power on”, the main rotor mast has sustained
torsional yielding.
2.
Examine the mast for torsional yielding by doing a TIR
check. If the mast is outside the TIR tolerance, you can send the
mast to Bell Helicopter for analysis. If the mast shows signs of
torsional yielding, discard the mast assembly, the transmission
assembly, and the freewheel (outer race, inner race, and
clutch).
3.
If the mast has sustained torsional yielding, replace the
transmission corner mounts and the restraints.
4.
If the mast shows no sign of torsional yielding and if the
transmission shows no sign of damage, remove the mast and
the transmission assembly and write, “THIS MAST AND
TRANSMISSION ASSEMBLY WAS REMOVED FROM
SERVICE BECAUSE OF A SUDDEN STOPPAGE.” Send the
mast and transmission assembly to an approved facility for
overhaul.
5.
If there is large damage to the mast other than torsional
yielding, replace mast assembly and top case of transmission.
6.
Examine the transmission corner mounts and restraint
elastomeric for condition. Replace damaged parts.
Chapter 63
ENGINE TO TRANSMISSION DRIVESHAFT
1.
Remove and discard engine to transmission driveshaft
assembly.
Chapter 63
FREEWHEEL ASSEMBLY
1.
Remove and examine freewheel assembly. If the freewheel
outer shaft assembly is sheared, discard the outer shaft, the
inner shaft, and the sprag clutch assembly. Put tags on the parts
that remain and write, “THIS PART WAS REMOVED FROM
SERVICE BECAUSE OF A SUDDEN STOPPAGE.” Send the
remaining parts to an approved facility for overhaul.
CONDITIONAL INSPECTIONS
5-28. SUDDEN STOPPAGE — MAIN ROTOR — POWER “ON” OR “OFF” (CONT)
DATA REFERENCE
INSPECTION TASK DESCRIPTION
INITIAL
MECH OTHER
