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OK, OK,....I always suspected that the folks who wrote the 320/360
construction manuals had a twisted and perverted sense of humor. Now it
is finally confirmed!
Chapter 20 page 2 begins a discussion of the proceedure for establishing
weight & balance.
#11 on page 20-4 says:
"You will now need to arrive at the moment weights of the nose gear
location and the main gear location. To do this, simply multiply the
weight of the nose gear by the distance from the datum point. Record
this number in column E. Do the same for the main gear."
If this requirement was remotely important to the weight & balance
proceedure, why do you think they waited until chapter 20 to tell you to
weigh your gear???? It does not take a rocket scientist to realize that
this suggestion might be better placed at the beginning of the gear
assembly chapter.
Are these weights the same for all 235/320/360 aircraft? I have no way
of knowing. I do know that in order to arrive at the accurate weight of
my particular gear, I should remove the gear from my plane and weigh it.
Am I missing something basic here? Are there multiple ways for doing
accurate weight & balance?
Angier Ames
[Angier... sometimes it is very hard to see the forest because there are
all those trees in the way <g>. The idea of weight and balance is to weigh the entire completed airframe and all of its fixed components to ascertain your aircraf's baseline CG without regard to the additional loads
which will be added to it (like fuel, pilot, pax, baggage, etc) to get it
ready to fly. The only way to get this weight is to weigh the complete airframe with everything attached, and the only way to do that is to roll the aircraft onto scales and record the weights at each wheel. By
applying these wights and their moments from the datum you establish the
empty CG. The factory isn't suggesting that you weigh the gear assemblies
by themselves, rather to use the weights at each of those points to find out how much the whole airframe weighs. We don't need to weigh
individual fixed components because they are always going to be there with
the airplane in a flyable condition. IOW, don't bother weighing your
gear unless the rest of the airplane is attached to them <g>. You might
want to take a look at the weight and balance worksheet that Rick Argente
provided on the LML website, it's a ZIPped Excel file located under
the W&B/Inspections link on the main page. It should give you the
complete picture of what's expected when doing your W&B.
<Marv> ]
LML website: http://www.olsusa.com/Users/Mkaye/maillist.html
Builders' Bookstore: http://www.buildersbooks.com/lancair
Please send your photos and drawings to marvkaye@olsusa.com.
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