I think making an untested alteration to the Lancair airframe is not wise. If you are going to do it, I suggest consulting with an aeronautical engineer who is familiar with the issues.
Having said that, it would seem to me that putting on tip tanks would put more mass in the periphery and because of conservation of angular momentum tend to dampen or stabilize yaw. Think ice skater bringing in arms and spinning faster.
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Colyn Case
Sent: Saturday, November 02, 2013 7:07 PM
To: Lancair Mailing List
Subject: [LML] Re: Tip tanks
Jim, I have absolutely no expertise in aircraft design. However, I will comment that the tail and rudder on the IV-P are pretty wimpy (in terms of authority) in the first place. Putting all that mass and drag out on the end of the long lever arm of the wing will certainly not improve that situation.
Retrospection on my project is that a) seemingly little changes have a lot of unanticipated ripple b) the value of the change often doesn't stack up to the value of having the airplane flying.
If it were me I would max the wetted area in the wing, buy the biggest belly tank I could find (proven) and get it flying.
On Nov 1, 2013, at 7:24 AM, JIM HANKINS wrote:
Does anyone know of a valid reason for not installing 15 gal tip tanks on a Lancair IVP turboprop? I made provisions for
this when I was building, but to my knowledge it has not been widely done. Adjustment of the angle of attack on the tanks would be welcome.
Most comments on this would be appreciated.