Message-ID: <39E07884.75BF0915@regandesigns.com>
Date: Sun, 08 Oct 2000 08:37:08 -0500
From: Brent Regan <brent@regandesigns.com>
To: Lancair List <lancair.list@olsusa.com>
Subject: Re: Hard Landing
Reply-To: lancair.list@olsusa.com
Mime-Version: 1.0

          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>>
          <<  Lancair Builders' Mail List  >>
          <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> 
>>
My condolences to Hal on the loss of his "baby". I was relieved that only
the airplane was wounded.

In the subsequent discussions I didn't see any mention of the fact that
stall speed increases with altitude. Specifically it increases as the square
root of the inverse of the Density Ratio. At Kernville, on a standard day,
you loose about 4 Kts, or about a 1/3 of your landing stall margin. A
standard day at that altitude is 50 degrees F. If it is a warm day, say 80
F, then you will loose another 4 Kts to density altitude.

If I were to land my IV at Kernville in the summer, I would be looking at a
75 Kt stall speed dirty and a 88 Kt stall speed clean!

If I flew into Leadville CO  (9,927') on a standard day (23 Deg F),  my
landing configuration stall speed would be 79 Kts and clean would be 93 Kts.

An excellent book on aerodynamics for pilots is "Aerodynamics for Naval
Aviators". A must read for pilots of high performance airplanes. Before I
get hammered on this one, I know that real Naval aviators don't consider
Lancairs "high performance, BUT for the rest of us mere mortals, this book
touches on areas that are not normally covered that are applicable to our
airplanes.

Regards
Brent Regan

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
LML website:   http://www.olsusa.com/Users/Mkaye/maillist.html
LML Builders' Bookstore:   http://www.buildersbooks.com/lancair

Please send your photos and drawings to marvkaye@olsusa.com.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>