Correction
My figures were slightly off.. Below is an exerpt from the MM..
flight time + (2.5 X Hoist cycles) = hours.. is the actual formula
External Hoist Operation
For the parts listed in Table 5 a life penalty must be mandatorily applied whenever an external hoist lift is performed.
The external hoist lift is defined as an unreeling and recovery of the cable with a load attached to the hook, independent of the length of the cable that is deployed/recovered. An unreeling/recovery of the cable with no load on the hook is not considered to be a lift. Any operation where a load is applied for half the operation (i.e. unreeling or recovery) must be considered as one lift.
Increase the flying hour by the specified value for each external hoist lift. The penalty is applicable only to flying hours.
Table 5 External Hoist Lift - Life penalty factor
Ref Part Part number Life penalty factor
RL022 MGB Shaft, Main Rotor 3G6320A01852 2.5
MGB Shaft, Main Rotor 3G6320A01853 2.5
E.g.: MGB shaft, main rotor: Flight time = 2 FH. Number of rescue hoist lifts = 3. Total accumulated FH = 2 + (2.5 x 3) = 9.5 FH.