Some RV-10 test flight numbers at full gross near aft CG

Power at idle...mine stalls at 54 kias full gross, full flaps, near aft cg limit with family and baggage. Our descent rate is 900 fpm. With full flaps there is very little to no tail shake before stalling due to increased wing downwash. This can make it very dangerous in the pattern if the incorrect response is made.

It stalls at 64 kias with flaps set to reflex. With no flaps, I have to hold stick full aft with "rocking horse" motion as tail gets into wing wake/downwash. Difficult to get into a deep stall with no flaps. Our descent rate is 1400 fpm.

Flying solo, cg about 3/4" aft of fwd limit and full fuel, these numbers drop about 6 kias.

On landing, at stall 1' or less AGL, my IAS is about 8 kts higher. Of course I don't pay any attention to ASI once below 10' or so.

During stall practice my ailerons still have a little effectiveness, but I always raise the wing with rudder. We practice as often as possible.

We get about 2 nm glide for every 1000' agl with prop full aft/coarse pitch, engine at idle, mixture leaned for altitude. We descend at 500 fpm at 80-85 kias. Glide Ratio= 10:1. With prop forward Glide Ratio goes to 8.5:1 and descent rate to 800 fpm.

Thanks for that Wayne. Good info.

Were glide numbers light or heavy?

BobTurner said:

Were glide numbers light or heavy?

Click to expand...

All of these numbers came from our full gross- 2700 lbs, nearly full fuel, near aft CG, family proficiency flight yesterday. Our numbers are from our GRT EFIS and Garmin 496, so not an exact science. On our glide, we also had a 5-10 kt wind 90 deg to our right. We started 5,000' above pattern altitude at 10 nm from near ctr of airport and by the time we were midfield downwind, we were 200-300 below PA. We would have made it to the approach end just barely, as we were using PA as rwy elevation. We like that 1000' cushion when practicing. If I had an actual engine failure, I would have had mixture to ICO, throttle fully open to lessen pumping losses, alternator off and four fresh air intakes closed for slightly reduced drag. With prop knob full aft/coarse pitch, engine idling, at 80-85 kias, our rpm was at 1,100. Pulling mixture it dropped to 650-700 rpm with a slight noise decrease. We have Hartzell 2 blade BA prop. We have practiced this a lot and have found 2 nm/1000' to be about our limit. We usually fly 8-16K feet AGL, so that provides us with a 16-32 nm no wind glide distance. We like the new distance rings on Foreflight just for this purpose. One of my little navigators jobs are to always know where the nearest airport is, how high above airport elevation, distance/heading to fly, whether we could make it or not with winds and runway/freq information. The family does not care much for stall and slow flight practice, but they realize how important it is for me.

Practise "High Key"

Wayne, a couple of years ago, there was a posting by Doug Rozendahl about the military type of "High Key" approach in their T-28's.

Essentially, it is that altitude, for your airplane, that is the minimum required to glide from the downwind leg, opposite the numbers, to a safe landing during a 180 degree descent to touchdown.

My -10 can do that from 1,000' AGL and I often practice the maneuver. Here is a link to the military version. Scroll down to High key portion:

http://stm.laartcc.org/Special+Military+Procedures

I try to plan a High key arrival from whatever altitude I'm flying at, in the event of an emergency or off-field landing. Arriving on a downwind to a field or pasture, at high key, eliminates a lot of guesswork if you have practiced and know your airplane's capability.

Best,

We are going to practice some more simulated engine outs on our next flight. It is not as easy as it seems if we don't practice it often. Learning to keep those flaps up until the runway is assured. Down low on base leg without power, you really get a sense for altitude loss in a turn, especially if one puts the flaps down too early. Since we do 95% of our flying at full gross weight, that is how we practice.

It seems like the worst possible time to have engine troubles are below 700' AGL on climb out or just after turning from crosswind to downwind leg. We were thinking about the RV-7 accident with engine trouble on downwind last month. That runway is like a magnet when we have trouble. Like you say, get to know our capabilities, so that is one less distraction in an actual emergency. If we are used to timing our flare for a 500 fpm descent/power above idle, then 900-1400 fpm is a going to be a big change. At full gross, full flaps and 70 kts over the numbers, we can get into an accelerated stall in ground effect while stopping the descent. You want to be very close to runway when this happens. There is not much time/room for misjudging. Have fun, practice a lot and be safe.

Most of my landings are with power at idle and a fairly steep descent rate that my family thinks that is normal. Then I do one at a std 3 deg, 500 fpm...it is easier to get a greaser that way, but we sure don't want engine problems at that point.