Message-ID: <01BDE36B.315BD670.ed@testelectronics.com>
From: Ed Armstrong <ed@testelectronics.com>
Reply-To: "ed@testelectronics.com" <ed@testelectronics.com>
To: "Lancair [Lancair.List@Olsusa.Com] (E-mail)" <lancair.list@olsusa.com>
Subject: Weight and Balances
Date: Sat, 19 Sep 1998 01:16:55 -0700
Organization: Test Electronics
Mime-Version: 1.0

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Grady Asks
In some of the weight/balance letters guys were saying that they were going 
to "up their gross weight to 2000 pounds". Where would I get information on 
doing this (legality)?


Some may think that you can up the gross weight to 2000 lbs by sacrificing 
"G" ratings. You can do this for the wings. Just figure out how much the 
wings can support from the old ratings. The wings can support 1685 x 9 G's 
= 15,165 lbs. 15,165lbs / 2000 lbs =7.5G's. So if you rate your plane at 
7.5G's your wings can carry a gross load of 2000lbs. However, this is wrong 
because it doesn't cover everything. They are overlooking the real limiting 
factor, the landing gear. The Lancair 360 has recently been approved for an 
increase of 100lbs gross weight (max take off) is now 1785 lbs. However, if 
you take off at 1785lbs you better burn 100lbs of fuel before you land. 
Because, the landing weight is still rated at 1685lbs.

Now my question to everyone is; Is there a rule of thumb for calculating 
the safety factor of landing forces? Obviously the gear can support 
1785lbs. You can take off and taxi on it. So they must just be adding some 
landing force as a safety factor, and it is not much, all it takes is 1.06 
G's to make 1685 lbs go up to 1785 lbs. I think that is a very soft 
landing.


Regards,
Ed
Watsonville CA.