Mike – good to hear somebody talking about this and actually PRACTICING. Lancairs require a commitment to training and/or practice and building of one’s flight skills ON A REGULAR BASIS. If you don’t think that’s fun, you probably should be flying a Cirrus or something. The number of times you have personally practiced a “glide to landing” is inversely proportional to your odds of becoming a fatality statistic in an engine out.
David T.
Legacy
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of MikeEasley@aol.com
Sent: 07-17-11-Sun 10:11
To: lml@lancaironline.net
Subject: [LML] Re: another Lancair
Gliding your airplane to the ground and trying to hit your aim point about 1/3 down the runway is a very unnatural looking exercise, especially in an airplane with high wing loading and a high stall speed. In my ES, it's somewhat of a "non-event" with the big wings and no gear to deal with. I still find it a challenge with my average pilot skills and only about 300 hours in my ES to have it feel comfortable. Combine that with the stress and IQ drop of a real emergency and I figure I need to be really good at it during training to be even close to competent in a real engine out, dead stick landing. During my training, I'm glad I have an ES, not a IV!
The FAA in its infinite wisdom, set the stall speed for single engine certified aircraft at a slow enough speed for average pilots to put the plane down off-airport and have that event be survivable. (You don't often hear the words FAA and wisdom in the same sentence) I'm sure they figured that single engine aircraft are more likely to lose all power compared to twins. That's a tradeoff they felt was wise for safety, even though it sacrifices some significant performance in cruise speed. Designs have gotten better over the years and now you can have a relatively fast airplane and still have a slow stall speed.
I believe the ES and the IV have the same wing design, but the ES is 40% larger. They use a very high lift airfoil at the root and a more benign airfoil at the tip. The root airfoil has a very quick change from high lift to stall with a small change angle of attack. The airfoil transitions linearly from the root to the tip with 2 degrees of washout on the ES. (not totally sure about the washout on the IV). The theory is you would never put the inboard airfoil into a stall because the tips would stall first. As the stall moved inward the whole wing would stall before the nasty stall characteristics of the root ever came into play. So in a typical training stall, Lancairs are pretty manageable, but in an emergency where you might stretch a glide, not drop the nose quickly enough, or attempt a 180 back to the runway, a deep stall could occur and that's a different story.
The IV and the rest of the Lancair fleet are examples of aircraft that lean more towards performance by sacrificing the stall speed and stall characteristics in exchange for cruise speed. Less wing area, choice of airfoil, washout, empennage area, etc. can really increase the performance in cruise, but it comes at a price on the slow end of the performance envelope. Too many pilots transitioning from single engine certified aircraft to a Lancair don't take that difference seriously enough.