PDA

View Full Version : Helicopter MZFW weights


AT Mov
25th Jul 2012, 09:36
Hi

hope someone can help, I am looking for GENERIC (planning figures) for MZFW, OEW for all civil types?

Anyone able to offer a good source?

Thanks
Pete

212man
25th Jul 2012, 09:43
Helicopters don't have MZFWs - it's a FW limit associated (mainly) with bending moments at the wing root. Obviously, they do have ZFWs, but the maximum will just be the MTOM minus the maximum fuel capacity!

As an aside, some operators use the term ZFW incorrectly in lieu of Dry Operating Mass.

AT Mov
25th Jul 2012, 10:02
Thanks, goes a loooong way to explaining the lack of data out there!

Pete

paco
25th Jul 2012, 11:49
The reason for using a ZFW on a helicopter is to do with controllability - that is, you calculate the zero weight CG first to make sure you're still in the plot with no fuel, then work it out for the fuel load. But there is no official list, as the actual ZFW would be in the weight schedule.

Phil

CS-Hover
25th Jul 2012, 12:15
...you calculate the zero weight CG first to make sure you're still in the plot with no fuel, then work it out for the fuel load.

shouldn't be the other way around, at least for specific operations, like offshore, where distance and reserves is more fixed (you need to go from A to B), than payload?

calculate the OW for that mission, and check CG is ok, then load (payload), as possible until the limits. Of course in missions where the payload is fixed (cannot unload payload), the way you said is better.

where I'm wrong ? :O

regards

SASless
25th Jul 2012, 12:18
Zero fuel will definitely affect controllability!