Airport turnback procedure

[RV8R999]

Having taking Professor Robert E. Ball's masters level course in Air Combat Survivability, to which he wrote and published the test book called "The Fundamentals Of Aircraft Combat Survivability Analysis and Design" and is probably THE expert on the subject, and looking through the text as I write this - a mathematical relationship between energy and survivability doesn't exist in such simplistic terms as "it's a log function". The structure, restraints, pilot anthropomorphic (fancy way of saying size) measurements, helmet, the impulse at impact (delta momentum between two given time periods), fuel system (is it a pressure or vacuum system, self sealing bladders, etc.), seat angle, gear configuration, and on and on all significantly affect the survivability.


It is pure silliness to suggest any one course of action is better or worse than another as each must be determined based solely upon the circumstances at the moment the decision must be made - this is called judgement.

[the_other_dougreeves]

Originally Posted by JonJay

This is how I was taught, and will use this procedure on any engine out;

Establish best glide
Find your field or landing area (you hope there is one out there!) and manuever toward it.
Troubleshoot if you have time but never give up the field and always fly the airplane.

If I have established best glide, and I can aquire the field behind me in confidence, I have enough altitude to turn back.

I'm not a CFI, I haven't landed an Airbus in a public waterway, and I didn't stay at a Holiday Inn Express last night, but in my glider flying (both as a student and CFI-G trainee), I've had plenty of simulated rope breaks (PT3) in the 200-300' range. I've also tried it in my CT at about 600ft AGL.

In both powered and unpowered aircraft, I've never took the time to establish best glide to assess where to go and start maneuvering. If you're at 500AGL, don't bother to establish best glide right away - you have more important things to do, like make sure you have enough speed (it's amazing how much you have to push the nose down, and if you stall it, you're done), start turning and pick up your landing point. Once you're well into the turn with your landing point picked up, then focus on best L/D if you need it. Chances are in a RV you're going to be high and need to bleed off energy anyway (slip), so best L/D isn't always what you want.

Second, you should already know whether you're going to return and land downwind because you should have already called your decision height. In the glider, if a student fails to tell the instructor their decision height for that tow or doesn't call it once you pass it, we will probably give them a PT3. Lots goes into the choice of decision height - wind (too strong to land downwind?), runway layout, operations (are you going to crash into a line of gliders and towplanes?), etc. Taking 5-10 seconds before pushing the throttle to consider where you will go could be the difference between making it or not.

TODR

[Brantel]

Originally Posted by B25Flyer

Turning from x-wind to downwind with partial power is not a turnback from an EFATO...

This highlights one of the problems with this discussion. What constitutes a turnback after EFATO versus flying back to the airport and landing.

I miss worded my post above and have edited it. I was not "Crosswind" I had just started my Crosswind Turn from the departure course. Sorry for the confusion. To further clarify, I made about a 165-170° turn at little more than idle power. This by no means makes me a super pilot. I just followed my training and selected the best choice I had at the time.

In my opinion any loss of engine power before reaching pattern altitude is an EFATO. Night failures increase the risk by many times I am sure.

I think we can all agree that we are discussing anything from ~ 200ft to 1000ft AGL. Anything less is pointless to debate and anything higher should be doable by most proficient pilots unless we are already outside of the glide range of a particular airplane.

Is a successful 180° turnback from 500' after a complete EFATO not "Flying back to the airport and landing"?

[Phlyan Pan]

Originally Posted by johnny stick

So I have a question, why is everyone attempting these turnbacks at an airspeed close to stall? I would think a turn back at best glide, or even higher, would produce the least altitude lost. Close to a stall, the plane is in a mush with very poor glide ratio. This is a very inefficient way to produce the turning force necessary to bring the plane round. Granted a higher airspeed produces a greater turn radius, but I think turn radius is not the biggest worry,it is altitude lost. Maybe there is a math problem in here that will answer the question.

The issue here is glide range. At a specific altitude you have a specific linear range you can cover before you meet mother earth. (L/D) A larger circle eats up more of that distance, think about the circumference of a circle...a larger circle is going to make you travel a longer distance to get around it. The steep turn is less efficient, but the less distance traveled makes up for it.

[Ron Lee]

Originally Posted by B25Flyer

Someone brought this up earlier, but landing into the wind is critical.. A 10 knot wind and a 45 knot stall speed plus a 5 not margin means a 40 knot accident into the wind and a 60 knot crash down wind.

This is 50% increase in energy, I'll defer to the engineers, but energy is not directly related to survivability, I believe it is like lift, a log function... That means a lot less survivable.

Actually I think it is a difference of 2.25 times higher at 60 versus 40.

Non trivial.

[RV6airplanePilot]

http://www.youtube.com/watch?v=ywuEUVZ3epo

All the talk about safety motivated me to practice. This was after 3 flights with simulations starting at 3800 AGL this week. I did not pull the prop control since the engine was providing idle thrust; these 2 issues have some degree of offset. I need to quantify in the future.
Dale
RV6a Hartzell c/s, Grand Rapids Sport SX (synthetic vision)

[Bavafa]

Originally Posted by RV6airplanePilot

http://www.youtube.com/watch?v=ywuEUVZ3epo

All the talk about safety motivated me to practice. This was after 3 flights with simulations starting at 3800 AGL this week. I did not pull the prop control since the engine was providing idle thrust; these 2 issues have some degree of offset. I need to quantify in the future.
Dale
RV6a Hartzell c/s, Grand Rapids Sport SX (synthetic vision)

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This is a great video and a great job. The numbers/performance is very similar to my test with is with similar type engine/prop.