Hailey, ID experience
Well this is fairly timely. I've just done my first few high altitude takeoffs in my RV7A. Around 6500' DA, 2 people, half fuel, WhirlWind constant speed prop, 190ish HP (mattituck 180 with 9.2:1 pistons). Mid 50's temp, 1rst takeoff was downwind but less than 10kts. No really accurate way of measuring distance but my impressions were:
Downwind takeoff: I always keep the stick back until the nosewheel comes off and then keep the deck angle at the climb attitude. The period of time between when the nosewheel came off and when the mains came off was longer by at least 5 seconds and when I was off I was slow and things were mushy until I lowered the nose BELOW the climb angle and let the speed build. Bitching Betty (AOA) was no where near yelling at me but it was much mushier than normal. My normal takeoff aims for a climb at 110 to 120 kts for cooling. I'm oil temp limited right now.
2nd takeoff was another similar day but upwind in about 12kts. I modified my technique a bit by keeping the nosewheel down until I saw 40 kts then gently moved the stick aft until the nosewheel lifted. The transistion time was back to a more normal "nosewheel is up aaaaaand we're flying!"
On the downwind takeoff my guesstimate for ground roll would be around 1000 -1200' and on the upwind it was much closer to "normal" and would guess around 500 -750' at most.
The deck angle was slightly different for a given airspeed...it seemed that at my normal climb deck angle for 115-120 kts I glanced at the airspeed indicator and was doing 95 kts so keep an easily fooled eye on airspeed not just in landing and takeoff but climb as well.
Bear in mind these are guesstimates by a low time pilot not using good ground references for measuring. I'll try to get better data and report back.
All best
Jeremy Constant
RV7A, around 60hrs
