In the UK the CAA are mainly interested in Flight Time hence for an R22 a 2200hr Datcon reading equates to 1964 flight hours (in other words for maintenance purposes which ever is reached first).
How can they differ.
For each & every flight, as warm up & cool down times added together average 0.1 (6mins) summer or winter a commercial ship generally does a lot more short flights i.e. lessons, trial flights, sight seeing etc therefore because of the above it reaches its 2200hr Datcon time first.
Whereas a privateer's ship normally is not up/down up/down as frequently & generally does longer sessions, therefore it follows it will reach its 1964 flight hours of first.
Since March 2006 JAR-FCL 1.001
Definitions, paragraph 2)
Flight Time. Clearly States that
The total time from the moment an aircraft first moves for the purpose of taking off until the moment it finally comes to rest at the end of the flight.
In other words Flight Time in any fixed gear chopper is logged as the first time after start up the skids leave the deck to the last time they touch down again before shutdown.
That’s just how it should be (after all, what is flight).
In an R44, as the Datcon also requires the collective to be raised to function, Flight Time & Datcon time as a rule generally coincide (unless you spend a lot of time doing autos).
It is also interesting to note that the R22 maintenance manual does indeed state that if an hour meter activated by the collective is used, one must multiply that figure by 1.12 for correct time in service. However in the R44 maintenance manual no reference to that figure is given other than it is the
operator's responsibility to maintain accurate time in service.
Although 236hrs could be at stake here to keep inside the law I guess all owners with (hour meters activated by the collective) should consult their respective authorities for the definitive answer as not only fatigue life's could be effected but your insurance or your life may depend on it.
