what AGL altitude to return to runway?

[brian]

Do you folks practice a "return to runway" scenario? When I took my RV training with Jan Bussell, we did it several times at 400' (in actual takeoff conditions - 400' AGL). I've been meaning to try it in my own RV, so I went out for awhile this afternoon and did it over and over for about an hour at 3500-4000'.

Assuming 100 mph takeoff climbout speed, I could easily do it in 400', mostly in about 300'. I did a couple hundred feet a couple times, but that's cuz even after chopping the throttle to idle, the aircraft would climb 1-200' more before losing altitude.

So then I'd get in a climb attitude, 100 mph, chop the throttle, then wait until altitude started falling, then kick it around 180 degrees at about 45 degree bank, 85-90 mph. Sometimes 300' if I did it well, 400' pretty easily. I found I needed a fair amount of back pressure to keep airspeed (and altitude loss) from getting excessive.

This was with 1/2 fuel, no passenger. I should also test it with full fuel and a passenger, but I'm not too sure my wife will be very thrilled with the idea.

Do you practice this? What numbers do you use and what results do you get?

[Jason Krause]

After practicing the return to runway in a few RV's I had to do it for real in a Kit Fox at CHD....although my heart was beating, knew exactly what to do.

Half full and slow, I have made it at about 250 feet AGL in my -6A.....but that seems right on the edge, also 200ft in a -9. I've tried a few different scenarios on a 5k ft. dirt strip, altitude seems to be better than airspeed in this situation. I find getting through the turn with the nose pointed down works best.

Having the altitude in the middle of the runway can make things a little tricky. I like to get the wheels off, hold it low for a few, build speed then pitch up and climb fast.

Did some return to runway practice at DVT one night after the tower was closed. Having the parallel runways made it much easier. Just had to avoid banging a runway edge light with the wing tip.

I highly recommend this type of practice flying.

[BobTurner]

Remember that unless there's a parallel runway you need more than a 180. In fact, to be conservative, you should try a 270 followed by a 90 degree turn the other way. That's twice as much as a 180!

In theory best glide IAS (no wind) varies as the square root of the weight, e.g., if you're 20% heavier, use a 10% higher speed.

[jetdriven]

This has been discussed ad nauseum on Beechtalk. It is such a hazardous maneuver that the very attempt of it is cutting it close. Mooney proficiency clinic and Bonanza Pilot Proficiency Program have all removed it from their syllabus after fatal crashes.

Around 700-800' is where you might be able to pull it off. And doing so requires a 45-60 degree bank at close to stall speed. Any mismanagement is going to result in a stall/spin/crash/burn. Unless faced with a brick wall, I am taking the straight ahead +/- 45 degree turn method. Crash the plane, take the insurance payoff, live to fight another day.

[brian]

Originally Posted by BobTurner

Remember that unless there's a parallel runway you need more than a 180. In fact, to be conservative, you should try a 270 followed by a 90 degree turn the other way. That's twice as much as a 180!

I've heard this, but my experience in training with Jan and in today's session with my own -6A is that if you're fairly aggressive about turning it (45 degrees bank & no delay), there really isn't that much offset. When I was doing it today, I was using power lines as a guide (the only straight terrain feature in NH) and not the compass, so I checked finishing altitude when I was back over the power line and lined up with it. So it probably was a bit more than 180 degrees.

[simpkinsona]

I have practiced this at altitude to find the best techniques for myself and my airplane at the initial climb speeds I use. I don't have a hard an fast number for all situations however. It varies with all the variables of the individual flight. In some situations I would not attempt it unless I've turned crosswind already. I use a conservative approach to this maneuver. I take off and as I climb I judge when I have enough altitude to turn around. I do this on every take-off. Don't get into the mind set that you can always do it from X amount of altitude.

-Andy

[MauiLvrs]

Originally Posted by brian

I've heard this, but my experience in training with Jan and in today's session with my own -6A is that if you're fairly aggressive about turning it (45 degrees bank & no delay.

Interesting that your experience defies the laws of math and physics.

Try this...
Go to the airport.
Take off - climb - accelerate to 100
Make a 45 deg bank 180 degree turn.

Like Bob said ... you will not find the runway in front of you ... unless there is a significant cross wind to blow you back over it.

Math and physics...

[Snowflake]

Originally Posted by brian

I've heard this, but my experience in training with Jan and in today's session with my own -6A is that if you're fairly aggressive about turning it (45 degrees bank & no delay), there really isn't that much offset.

To quote another famous engineer, "you cannae change the laws of physics, captain!" Unless you're turning in the vertical plane, like a split-s, on a day with no wind you can't make a 180 degree turn from the runway centerline, and end up pointing at the runway.

The sneaky way to build in some margin on this manoeuver, is to *not* correct for crosswind drift on climb out. Drift downwind a bit. The farther downwind, the less turning you'll need to line up again. I haven't practiced this manoeuver yet, but I probably should. I have in mind that allowing, or even introducing, a downwind drift while climbing, up to something like 500', and then reeling that drift back in as I gain altitude margin, might be the best practice.

But maybe I over-think these things... :P

[gtmule]

180 isn't enough turn of course, but I submit that no more than 200, maybe 220 is required if you're willing to approach the runway from something less than perfectly parallel...it's moore of a teardrop shape than something that looks like a procedure turn

[ao.frog]

.... 900' AGL as minimum for the return.

The last point on my "before takeoff checklist" is:
ENGINE FAIL PROCEDURE - REWIEW

Under this point, I consider terrain, weather, wind, RWY-length etc and make a mental plan for low altitude engine failure.

The general AGL altitudes I use are:

Below 300: max 30* of turn
Beetween 300 and 600: max 90* of turn
Beetween 600 and 900: max 180* of turn
Above 900: CONSIDER returning to RWY.

I have found that when I use these altitudes, I'll have a reasonable amount of time to analyze, decide and react and then have reasonable time and altitude to find a place to set the bird down, and finally concentrate on making a good landing.

The 3-6-9 numbers are easy to remember when you are in a hurry too. (that is when the fan is spooling down in front of you)