James, I'm based at Los Alamos, about 50 miles north of you with a runway elevation of 7171'. ?I assume you are based at Double Eagle?
If you have been flying other planes out of AEG, you already know what you need to know about flying at higher DA. ?The plane will use more runway on take off and landing, but will do it quite easily with the runway lengths at AEG. ?The same indicated air speeds apply as at any other altitude. ?Just be aware that your ground speeds are significantly higher. If I am looking for a smooth landing by letting the plane gently settle onto the mains for a wheel landing, I'll burn up 3000 or 4000' of runway if I don't use any braking. ?As pertaining to the other thread about landings, if you control your speed closely for a three point short field landing, you can put it down and be stopped in less than 2500'. For take off, if I am flying at 1200# gross on a 10,000' DA day, I'll use roughly 2500' of runway getting off the ground. ?My normal take off method is to keep the tail pinned down until I see 40 mph indicated, which is when I have good rudder authority to counter significant crosswinds, then raise the tail for better visibility down the runway until I see 60 mph IAS. ?That's my rotation speed that gives me a good buffer above stall, so I can immediately establish a good climb. ?The plane is capable of getting off shorter using short field take off techniques. ? Your numbers may be different due to a different wing and/or air speed calibration, but the principles are the same. Per your questions: 1. Yes, DA degrades both engine and wing performance. ?That's why the runways are so long at higher altitude airports like ours. 2. Same indicated air speeds apply regardless of DA. ?It's the True Air Speed that is different. 3. Yes, the air is less dense, but you are also in ground effect, so you get good compressibility against the ground. ?This isn't something I have noticed in 1000+ hrs in my KR flying up here. ?There are no days where the DA is too high for my KR. ?I have flown with the DA as high as 11,000' and I don't make hard landings. :o) Compared to the Vari-Eze and Long-Eze, the KR doesn't use nearly as much runway at the high DA airports. Drop me an email some weekend when the winds aren't howling and I'll run down to AEG in the KR for breakfast (always looking for a breakfast destination). ?Or I can come pick you up in the SuperCub and show you Los Alamos, which would make you really appreciate the multiple runways at AEG. ?:o) -Jeff Scott Los Alamos, NM http://jeffsplanes.com > ----- Original Message ----- > From: James Dunn > Sent: 02/20/14 07:40 AM > To: krnet at list.krnet.org > Subject: KR> KR-2 with VW type 4 [] Runway performance at 5000 to 8000 feet > > Does anyone have a KR-2 and have experience with TO/Landings at high > altitude, hot dry runways? > > I live in Albuquerque, NM where the airfield is at 5800 ASL > > I'm considering buying a KR-2 with a VW type 4 engine > > I have not been able to find any information about density altitude take-off > and landing roll-out > > I'm concerned about: > 1. density altitude degrading engine performance > 2. higher airspeed needed for the same lift off / sink rate > 3. 140 degree pavement creating a low density ground effect envelope (less > molecules / volume due to local runway temp) and the potential for causing > hard landings > > > --? > > James Dunn > My previous ride was a Vari-eze with an O-200
