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The 180-degree Turn

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yankee-flyer

Well Known Member
Made a few tests Monday and the best I could do with Van's recommended 85-know best glide speed was losing 500 feet in the 180 turn. Anyone else tried it? And that brings up another question-- is 85 knots really the best glide speed? Seems awfully fast. I plan to enlist a data recorder and try some tests, but has anyone else done that?

Wayne 120241/143WM
 
Just remember that a "return to the runway" is considerably more than a 180? turn.
 
Depends on which model you fly.

500' will have me in my RV10 crashing. Yes Crashing. Off the far end of the runway!

Best executed at say 400' for me. But that may not be you or the next guy. I have tested this to 300' and all going well. But 400' for me is OK.

KNOW YOUR AEROPLANE

Simply put you also need to practise this at low level, the ground rush effect is very powerful and will screw people over.

You cant make rule of thumbs here. You need proper training and practise.

Doug Rozendahl will debate with me with vigour, despite me having data, but he is still right.......most do not and can not pull it off. You need to know how and when and to what extent. It may not be a 180 you need for the best outcome.

Best practise is a minimum 45 degree turn just off the buffet and roll out to 45 then again onto the strip.

https://www.youtube.com/watch?v=uvTUW28JnpY

This is a glide approach, then a 500' then a 400'. This is NOT necessarily how well YOU can do it in your plane. If you want to develop the skill, get a good AG pilot or aerobatic instructor. This is not for your average flying school CFI.
 
There has been plenty said (pro and con) about turn back to the runway (just do a search).

The topic seems to bring out some strong points of view - the bottom line is to do as you're intending (find out what your aircraft will really do). Be sure to allow for
- a difference between a idling engine and one that's dead and windmilling,
- reaction time to a loss of engine, and
- with LSA there will be a rapid loss of airspeed if the engine really "corks."
Also, it probably wouldn't be a bad idea to search the internet for some videos of skidding turns into a spin - you definitely want to avoid that.

It wouldn't seem shocking if you concluded that below 1000 AGL you might be better off to choose to land straight ahead.

Dan
 
Getting back to the "glide speed" to target for this emergency situation, the range cited by Van's is 60-85 kts with the lower speed giving the lowest rate of decent. Thats probably the better speed to use for this type of emergency.

-------------------------------------
[Van's Fight Training Supplement]

FORCED LANDING (Complete Power Failure)
If the engine cannot be restarted in flight, trim the aircraft to the recommended glide speed. Remain within gliding
distance of the intended point of landing. Maintain a higher and closer pattern than normal making allowance for
wind.
Extending flaps or slipping the aircraft can lose additional altitude. Diving the aircraft in an attempt to lose altitude
when flying into a headwind will only increase the required landing distance.
? Maximum gliding distance airspeed ? 85 kts Minimum rate of descent airspeed- 60 kts
? Fuel Shut-Off Valve ? OFF
? Flaps ? UP to increase glide range
? Radio ? MAYDAY 121.5 MHz
? Attempt to position the aircraft approximately 1000 feet above ground level (AGL) when on downwind and
abeam the intended point of landing.
? Ignition switches ? OFF
? On Final Approach
a) Airspeed ? 60 kts (55 kts minimum)
b) Flaps ? DOWN after intended point of landing assured
? Touchdown with minimum airspeed particularly if landing on rough terrain.
 
What I've found is that a steep turn, not quite to the stall (maintain full control!), is the quickest. As the airplane approaches the runway or the ground, get rid of any excess speed, converting it to range.

It's not a steady-state maneuver if you're close to the ground. It uses up your kinetic energy, converting it to less altitude loss. I've found that the minimum altitude loss requires a lot of maneuvering and significant back angles and some g, although the amount will depend on the aircraft.

It's also not a 180 degree turn. That will put you parallel to the runway but offset to the side. Turn past 180, then turn back, and yes, this takes longer and uses more altitude than a 180.

Plan on trying it with plenty of altitude. And count to three or four before starting because in real life you won't be spring-loaded to the turn. There will be a few seconds of shock or surprise.

Dave
 
David Paule said:
What I've found is that a steep turn, not quite to the stall (maintain full control!), is the quickest. As the airplane approaches the runway or the ground, get rid of any excess speed, converting it to range.

It's not a steady-state maneuver if you're close to the ground. It uses up your kinetic energy, converting it to less altitude loss. I've found that the minimum altitude loss requires a lot of maneuvering and significant back angles and some g, although the amount will depend on the aircraft.

It's also not a 180 degree turn. That will put you parallel to the runway but offset to the side. Turn past 180, then turn back, and yes, this takes longer and uses more altitude than a 180.

Plan on trying it with plenty of altitude. And count to three or four before starting because in real life you won't be spring-loaded to the turn. There will be a few seconds of shock or surprise.

Dave
Click to expand...
What Dave said. Add that reaction time to your test. Maneuver more aggressively early - gentle all the way around doesn't work well. Good maneuver with which to be proficient. Remember the winds - they matter. I'd take a 40-kt into a field before a 70-kt into a hangar.
 
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yankee-flyer said:
Made a few tests Monday and the best I could do with Van's recommended 85-know best glide speed was losing 500 feet in the 180 turn. Anyone else tried it? And that brings up another question-- is 85 knots really the best glide speed? Seems awfully fast. I plan to enlist a data recorder and try some tests, but has anyone else done that?

Wayne 120241/143WM
Click to expand...

The best glide speed is now 63kts. Down load the latest POH from Vans web site.;)
 
Testing and knowing your airplane is good - great in fact!

Just remember that every pilot who tried the turnback and died THOUGHT that they could make it as well. If you THINK that you can make it, that doesn't put you in great company.

I've said it before - risk trades. If you land straight ahead, evidence shows you will most likely survive, with a damaged airplane. Turn back and make it, good for you! Turn back and don't make it - you are dead. Not injured, dead. Think about it in advance and decide what works best for you....oh, and those passengers who put their lives completely in your hands.
 
If I may turn the question around a bit, consider taking off from a very short runway - obviously you aren't going to try a 180 and that option is off the table. Now consider a very long runway (such as might be at a former USAF base). If you're you're still "low" when the engine conks out you still have runway left provided you dump energy quickly. If you climb out at Vx and you're high enough when you cross the end of the runway a 180 should be doable even with the reaction time delay (Yes I know that a 180 is actually a 210 plus a reverse 30). Both are obviously good outcomes (and a reason to love long runways!).

So my question is, under light wind conditions, what combination of min. runway length and min. altitude AGL does the 180 back to runway become a viable option for the average pilot in the RV-12? Thanks for your input.
 
Remember there is not one best glide speed. No wind at gross weight is what is published in certified aircraft. Lighter weight, that speed comes down (like the square root of the weight).
Headwind? Go faster.
Tailwind? Go slower.
 
Is best glide speed actually the best speed for 180 degree turn? A slower speed during the turn will make the radius shorter and keep the plane closer to the runway. The minimum rate decent speed of 55 knots will keep the RV-12 in the air longer, giving the wind more time to blow the plane closer to the airport. Many people have been killed when an airplane stalls close to the ground. The stall speed increases when turning. It is better to monitor the AOA which is not affected by G-forces in a turn.
Joe Gores
 
I think we would all agree that each airport is different and it's up to the pilot be aware of the airport surroundings at all times. There are several airports in our area where if you take off in one direction you have many choices straight ahead but taking off the opposite end gives you absolutely no choices and it might be worth the risk turning around depending on your altitude, speed, position, etc. Bottom line is it's good practice to know your plane and practice it's capabilities or lack of at different scenarios but if you continue to practice turning around at a particular altitude every time, odds are your engine won't remember that :eek: - Back to the glide speed, in my -7 the best glide speed was posted as 71 Knots when I bought it and for the most part it seems to be correct.
 
Remember, in a turn you're pulling some g. Because of that, the minimum sink speed and max L/D speed both increase by the square root of the g.

The quickest turn is at the maximum g you can pull. That's why earlier I said it's not a steady state maneuver. You need to start with a steep turn and when you lose speed, make it shallower. But at all times you've got to maintain control.

It's kind of fun to practice this at altitude. You'll quickly get a feel for the various ways speed, bank angle and turn radius all work out. That said, Paul has it right: when it happens you've got to make a quick risk assessment and if you're critically low, probably the best thing is to go straight ahead under control.

One perhaps surprising possibility with a fast-climbing airplane and a headwind on the runway is that it's entirely possible, even likely, to complete the maneuver, roll out and find that you've overshot the runway. This is more than disconcerting, it can be fatal. I guess the phrase would be fatally embarrassing. You've got to use some judgement and not simply whip the plane into a tight turn.

You could easily be in a situation where if you turn now, you'll overshoot the runway, and if you turn later, you won't make it back.

Dave
 
Ideas to consider from the glider world, where we routinely practice the turn back to the runway from as low as 200 agl.

1) The optimum bank angle for least altitude loss v. rate of turn is 45 degrees. No more, no less.

2) Always turn into the cross wind for least displacement from the runway centerline.

The glider take off checklist includes 1) deciding before take off which way the turn will be if the rope breaks and 2) calling out 200 feet agl on climb out. The intention of both items is to get set mentally. If the rope breaks below 200 agl, you land straight ahead or make a partial turn either way to avoid obstructions.

We assume the rope will break (or the towplane engine will fail) on every take off.

The only difference for power would be the decision altitude.
 
Turnback

There is some excellent information available on this subject. Charlie Precourt devoted his Sport Aviation column to this last month.
Article by Van in current Kitplanes, excellent article about a real life scenario.
Sunrise Aviation is based at John Wayne Airport, really no place to go to the northeast. They teach turnback to students. They also have an excellent video but I don't remember how to find it. You could call them and ask.
One thing I NEVER see mentioned is the benefit of a shallow turn at some predetermined altitude, say 200', on takeoff. offset in the desired direction and then turn back parallel to the runway. Now you are in a position to make a true 180 turn back to the runway. If there is a crosswind, simply let the airplane drift until you are offset the desired amount.
The numbers that Charlies article uses are 500' for a 90 degree turn, 1000' for a 180. These are generic numbers that will vary considerably depending on the airplane.
 
videos

The sunrise videos can be found at sunriseaviation.com/turn-arounds
Videos were done in a Cessna 172 to a remote airstrip, simulated takeoff and climb, simulated engine failure at 500' AGL.
 
Mike S said:
Well, this is posted in the RV 12 forum, and he lists what looks like a 12 series serial number......
Click to expand...

And your point is?

The real point is take Paul Dye's post and compare it with mine. You can be in one camp or the other but never undecided.

In aviation if you only think you can....you can't. And this is PD's point exactly. Best to take plan A.

If you are Pierre Smith and have tested and practised, then you know for sure that Plan B is going to work, rather than just hoping it might.

Right now I need to go do some more practise as I am not current at the manoeuvre and my takeoff brief does not include it or the threshold at which it is available is higher. Today it is 700' and turn of the cross runway which is a 60 degree cross (the one in the video).

You need to know this before you roll. Always expect a failure and be pleasantly surprised when it does not.

DO NOT GO TRY THIS BY YOURSELF. YOU NEED AN EXPERT TRAINER. THAT MOST LIKEY IS NOT YOUR TYPICAL CFI.
 
yankee-flyer said:
that brings up another question-- is 85 knots really the best glide speed?
Wayne 120241/143WM
Click to expand...

RV10inOz said:
Depends on which model you fly.

500' will have me in my RV10 crashing. Yes Crashing. Off the far end of the runway!
Click to expand...

RV10inOz said:
And your point is?
Click to expand...

My point is that the OP was asking about a specific model, ( http://www.airport-data.com/aircraft/N143WM.html ) and your response about what your 10 will do is totally irrelevant to his question.

You are correct that testing in your own plane is the best way to get the info, which is what the OP did, and he is now looking to see if other 12 pilots can confirm his numbers.

Just trying to keep the thread on track.
 
No thanks!

A friend tried it back in '96 and stalled and spun it in. Well sort of spun it, he only made half a turn.

Two passengers were incinerated immediately and my buddy was tossed clear when his harness broke. Needless to say, he lived but was badly broken.

As Bob Hoover said, "Fly it as far into the crash you can."
 
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WOW-- Didn't mean

to generate this much response. Like I said, the best I could do was 500 feet-- that's knowing I was going to pull the power, with the engine at idle. I'm an aero engineer-- or at least was for 37 years, and didn't mean to imply that I would try it if things ever get quiet at 500 feet-- which would still put me over the runway on most days, but certainly not possible to get back down onto it. I was looking for information from others who may have experimented (at a VERY safe altitude) and it doesn't look like anyone has. Hopefully I'll be able to post some rate of descent numbers at various altitudes and configurations before too long. They WILL be with the engine at idle-- no way I'm gonna shut that off to get REAL numbers.

Wayne 120241/143WM, 240 hours since Sept. '10
 
Well, you are wondering if anyone had experimented.
I did. Last Sunday morning. The pattern was empty at Prescott, AZ where I base the plane. Standard RV9A with a three blade prop. O-320 engine.
I asked for the tower's permission to do simulated engine faiures at low altitude.
I did a series of these starting at 500 ft. AGL. I did not allow for 3-4 seconds reaction time.... I could have but didn't. It was planned, so I started my roll to the left as I chopped the power.
There was a 12/14 reported wind down the runway Sunday morning.
As I made the turns.... my ground speed picked up as physics dictates.
I made the turn back to a position to land back on the runway of departure each time. I did not actually touch down... as the tower was being very accomodating and I did a tear drop reversal turn back into the wind each time.
From 500 ft. agl and with an aggressive bank (more than 45 degrees) but not measured.... I actually had too little runway left going downwind.
As noted by another poster, that was not optimal.
I would have been able to dump flaps and ride the brakes to the end... in a real world scenario. The overrun area would have dissipated some energy and I would be probably be seeing some ILS lighting replaced. From 300 ft. AGL it still worked. Our normal runway 21L has had numerous fatalities off the departure end when engines failed. Riddled with power lines, small obstructions etc. Many obscured by brush and bushes. Great topic, glad you posted it. Cheers.
 
To keep the debate going

As some have noted,... It is possible to "make the turn"'......but to run out of runway,... (Not to mention higher landing speed due to tail wind)

So,....would you get to a point of taking off somewhere other than end of runway (I.e. midfield) as a routine,....or only if.....???

Is there some "known distribution" of engine failures,.... Or is it
More dependent on what is off the end(s)of the runway?
Or winds above x knots,...
Or....

Thoughts?
 
Apologies to the OP if only a specific model was of interest. Have only been in a 12 one time. I do, however, suggest the training and consequent decision about what to do in ANY plane... Regarding power failure on climbout be made in advance. And do not schedule this on Friday 13th.
 
Lote said:
2) Always turn into the cross wind for least displacement from the runway centerline.
Click to expand...
I've seen this debated (hotly) in the past on other forums.

Turning into wind ensures staying close to the centerline, but virtually guarantees that you'll overshoot the centerline when you turn back... Mentally, you'll be lulled into "oh, I can just tighten it a *little* bit" and try to make that turn.

Turning with the wind first takes you further off centerline, but will minimize the overshoot to final on the last turn. That's always been my plan for the RV, *if* I ever get around to trying this myself at altitude or when the airport is quiet.
 
MauiLvrs said:
All this practicing with the engine running will provide a different answer :eek:
Click to expand...

Yes, engine running and at altitude for safety. Is there a safer way to simulate zero thrust?

Never had a complete engine failure (thank goodness), but I always try to teach it's better to hit the trees on the end of the runway at 20 knts than stall/crash short at 60+ knts. I try to reinforce the fact that idle power is not the same as a frozen prop and to adjust accordingly. Aiming for touchdown 1/3-1/2 down a emergency landing area should give some margin on coming up short.
 
crabandy said:
Yes, engine running and at altitude for safety. Is there a safer way to simulate zero thrust?
Click to expand...
The problem is that with the engine running it doesn't do a very good job of simulating zero thrust.

So when the engine actually fails, the performance is likely noticeably different and not in a good way.
 
I have a fair amount of experience flying gliders (including 1000+ takeoffs/landings), and have had at least a dozen simulated rope breaks (initiated by sneaky CFI?s without warning) pulled on me. It?s part of the required training so it gets talked about and practiced quite a bit, but the protocol on this is universal (to my knowledge) to always turn INTO the wind. With that said, the direction of turn really depends on how much altitude margin (excess over the minimum required based on conditions) that you have. If you?re high enough you can turn anyway you want?even fly a normal pattern ground track. But if you have little altitude margin I believe that turning into the wind is safer. If you compare the risk management of turning into the wind and possibly overshooting the centerline when landing to the risk management of turning down wind and possibly not being able to make the runway I?d rather manage the former (which by the way, is really no big deal ? been there).

I would also like to comment on the seemingly common technique, when planning/practicing the 180 degree maneuver, to wait 3-4+ seconds AFTER simulated engine sputter/stoppage before beginning the turn. Please forgive, but this doesn?t make sense to me. Yes, I?ve heard the rationale that you may be surprised or confused in a real engine-out scenario and need this time to gather your wits and take appropriate action. I respectfully suggest that if this is the case there is trouble in paradise. In the best-case scenario, taking 3-4 seconds to figure this out if the fan goes quiet will materially limit your options and the likelihood of a successful outcome. In the worst case scenario?:eek::eek::eek:

Glider training teaches one to always assume that the rope will break or the tow plane will malfunction at low altitude. So for me, take off preparation in a powered aircraft ALWAYS includes an assumption that the engine will quit. Before every take off I make an assessment of wind and other relevant conditions, and a predetermination as to the safe minimum altitude and direction of turn that would be needed. Planning like this doesn?t take much time and quickly become second nature once you start doing it. Being prepared to act decisively in an emergency (close to the ground!), in addition to practicing the maneuver itself, just seems like a good idea?
 
I had some smart instructors so my take-off plan is always knowing the wind direction, knowing which way to turn into the wind and the decision altitude for a turn back. At some airports the wind direction is less important than other available runways, taxiways or open fields.
 
I practiced these turns recently and found that the tighter, higher G turns seemed to work best at not burning off altitude. the best result was from my instructor's suggestion, to immediately pull back on the stick when any engine problems first occur. if I did that and then waited 5 secs before turning the results were much better, as much as 100'. so my suggestion is to learn to react first by gaining altitude first and then start analyzing what is going wrong. I also call out critical altitude during takeoff.
 
Low Pass said:
A man's gotta know his limitations.

- Harry Callahan
Click to expand...

You're thinking "did he torque six AN-3 hinge bolts or only five?" Now to tell you the truth I forgot myself in all this excitement. :)

kjlpdx, my first reaction with a sputtering engine/loss of power would be forward stick, to maintain airspeed. I guess it depends on the amount of power loss.
 
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kjlpdx said:
I practiced these turns recently and found that the tighter, higher G turns seemed to work best at not burning off altitude. the best result was from my instructor's suggestion, to immediately pull back on the stick when any engine problems first occur. if I did that and then waited 5 secs before turning the results were much better, as much as 100'. so my suggestion is to learn to react first by gaining altitude first and then start analyzing what is going wrong. I also call out critical altitude during takeoff.
Click to expand...

In gliders I was taught to use a 45 degree bank for the turn back. I also remember an AOPA safety video from a few decades back that came to the same conclusion.
 
I am a glider instructor (not Will's) with well over 600 simulated rope breaks with students and Will learned well. The math and practice shows that a 45 degree banked turn gets you turned around with the least altitude lost.

Emergency plan before takeoff. Engine quits, establish glide speed while turning into the wind (unless obstacles are an issue), 45 deg bank. If you expect the emergency every time, the reaction delay is minimized but still a factor. If overrunning the runway is a possibility and it often is, you probably have sufficient altitude to reduce the bank angle, flaps down, slip etc to get down.

Sometimes the real challenge is when you have to much altitude, but not enough for a full pattern.

I have practiced this in my -6A at 400 ft as a hard minimum altitude for a turn. Never skid the turn or go below 1.3 Vso approach speed, your sink rate will go up and L/D down. Note that C/S prop will be different than fixed pitch.
 
Low Pass said:
A man's gotta know his limitations.

- Harry Callahan
Click to expand...

Dgamble said:
Or get married and have them constantly recited to him.
Click to expand...

OK, that was to funny not to quote...

On Subject:

As flightlogic has demonstrated in his 9A getting the turn done safely to align with the runway is not the only issue, having some runway left to land on is a problem.

I have very little SE time, and I'm used to a departure brief in a ME airplane. When I first got my RV-6 I looked at this issue to give myself a baseline on which to build a brief/plan for self. (OK Self, if the engine fails on departure we're going to...) I quickly discovered that due to the RV-6's climb and turning performance; and depending on the wind and TOGW, I could get the airplane turned back in alignment with the runway and - not have enough runway available to safely land on.

I need to get back out and do this again since it's been quite awhile and I've not done it since. I have a plan for my home airport for straight ahead/90/180ish turns after a power loss on departure. The landing areas and altitudes are already picked out. When I arrive at an unfamiliar field I try look around the departure end before I land to give me an idea of what my options are.

You'll notice I mention no numbers in post, different airplanes, pilots and conditions will result in different numbers. There's no magic pill. Remaining in control is what will keep you alive, you've got to temper everything you do with that in mind. As was stated previously, if there is any doubt, there is no doubt, choose another option if available. Plan ahead, you've got to have a plan in place otherwise you'll find your all out of time, talent and ideas...
 
if I am climbing at 80+mph and pull the throttle quickly to simulate power loss I can gain quite a bit of altitude immediately slowing to 60mph. no need for forward stick unless you climb out near stall speed. this, of course, raises the question of what is your turn around altitude and how confident are you to perform if close to that altitude? the day I practiced with the guy who taught me to fly, we couldn't do better any other way. yes, we needed forward stick to make the turn, but that initial altitude seemed impossible to regain with other procedures. if there are better methods, I'm happy to try them.
 
kjlpdx said:
.... the best result was from my instructor's suggestion, to immediately pull back on the stick when any engine problems first occur...
Click to expand...
...in order to convert speed to altitude and quickly move toward best glide speed? I could buy that, with anything other than a high performance (steep) climb.

Checked the numbers more closely and generally - when "heavy" - it would be best to just push over if power loss on climbout. When light, and climbing at Vy+10,15, then maybe some continued climb could be of benefit.

Bottom line, I think I'll push and keep the surplus airspeed for early maneuverability options.
 
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..if I am climbing at 80+mph and pull the throttle quickly to simulate power loss I can gain quite a bit of altitude immediately slowing to 60mph....
Click to expand...

True for a RV-6, but just be aware that this is much less so in LSA aircraft.

Dan
 
turnback

The optimum performance bank angle is 60 degrees. However there is so little difference in altitude loss between 45 and 60 degrees bank that 45 degrees should always be used.
The poster who said pull back on the stick if the engine quits is a perfect example of why people get killed on turnbacks. The higher the climb performance of the airplane, and the higher the climb angle, the greater the need to smoothly but aggressively push forward on the stick to get the nose below the horizon.
The first turn should always be into the wind unless unusual circumstances (terrain) prevents this.
Regarding props, with a fixed pitch there will not be a huge difference between windmilling and stopped prop. With a constant speed the difference will be very substantial.
 
I see the logic in trading altitude for speed, provided you quickly get the nose down after gaining that extra bit of altitude. Depends on steepness/speed of climb, and where your best glide speed is.

In a DA-20 flying out of John Wayne, our school had us routinely climb out at Vy (around 70 KIAS), and best glide was 73 KIAS, so immediate forward stick was the order of the day for an engine-out scenario. The idea of the Vy climb was to get altitude early as off-airport landing options are not great in the Irvine/Newport Beach area! :eek:
 
rightrudder said:
I see the logic in trading altitude for speed, provided you quickly get the nose down after gaining that extra bit of altitude. Depends on steepness/speed of climb, and where your best glide speed is.

In a DA-20 flying out of John Wayne, our school had us routinely climb out at Vy (around 70 KIAS), and best glide was 73 KIAS, so immediate forward stick was the order of the day for an engine-out scenario. The idea of the Vy climb was to get altitude early as off-airport landing options are not great in the Irvine/Newport Beach area! :eek:
Click to expand...

This might be enlightening as most schools do not teach this, because they often do not understand it. So much in flying schools is good, so much is just OWT's past down the years from 200 hour students teaching 20 hour students :mad:

Enjoy this, take what you want from it
http://www.advancedpilot.com/articles.php?action=article&articleid=1842
 
Interesting stuff, Oz. Yes, the debate will continue as long as little airplanes flit through the sky. If you're of the Vy school, you train the students to push the nose over immediately and you're at or close to best glide speed (YMMV depending on aircraft). Lower airspeed, yes, but more potential energy from altitude, and you're closer to the airport for a turnaround. A very low altitude failure at John Wayne? Veer right and land on 19R, some 5800 ft. You might get run over by a 737, but you take yer chances.

If I were flying out of, say, Chino, I think a shallower, faster climb makes a ton of sense. Many cow pastures, open fields and the like bode well for a successful off-airport landing. But around the urban environs of John Wayne I'd just as soon get altitude early, engine temps permitting.
 
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Another variable...

The tendency to over-rudder (skid) a turn in this situation has been noted above (..& is vary real : I have turned back from an engine-failure... not in an RV, though... and in that 'time-slows-down' fashion I remember noting the slip-ball and mentally yelling at myself to GET OFF THE RUDDER !.....)

...but I remember reading an article by Brian Lecomber (& I'd suggest that he knows more than most about high-performance manouvering...) in which he made the point that to reverse heading as quickly as possible in this situation, you ideally want to be slipping hard (..point being that more of the available lift is turning the aeroplane around, and less is devoted to keeping it up !)

...just highlights that there are lots of variables in this issue.... but as others have pointed out, I'm guessing that if I NEEDED to turn-back after takeoff in my RV4, I might be better off with a tighter turn-radius, & a higher ROD.
 
jrs14855 said:
Regarding props, with a fixed pitch there will not be a huge difference between windmilling and stopped prop.
Click to expand...
There is a noticeable difference in a Cessna 150. I haven't tried it in an RV, but the math says it should be significant. The catch is that it's a fair bit of work to get a metal prop stopped. Wood props stop easier due to lower inertia.

On climbout when it quits, don't waste time trying to stop the rotation. In cruise at 10000'? After you exhaust your re-start possibilities, then definitely consider stopping the prop and extending your glide.
 
The RV-12 POH gives the maximum gliding distance airspeed of 63 kts. Is that with engine idling or off?
According to my interpretation of John Bender's posting on THIS thread, the prop will windmill if the speed is much above 60 knots. A flight instructor told me that a plane such as the RV-12 will glide farther with the prop windmilling. Is that correct?
Joe Gores
 
jrs14855 said:
Sunrise Aviation is based at John Wayne Airport, really no place to go to the northeast. They teach turnback to students. They also have an excellent video but I don't remember how to find it. You could call them and ask.
One thing I NEVER see mentioned is the benefit of a shallow turn at some predetermined altitude, say 200', on takeoff. offset in the desired direction and then turn back parallel to the runway. Now you are in a position to make a true 180 turn back to the runway. If there is a crosswind, simply let the airplane drift until you are offset the desired amount.
Click to expand...

I believe the video you're referring to is here:
http://www.aerobats.com/seminar_02-07.html

Regarding the offset, that's exactly what happens at John Wayne Airport. Departures from 19L offset 15 degrees for wake turbulence and physical separation from airliners departing on the parallel runway. If you try to turn around, a right turn will not only be into the wind, but will also align you with the runway. Nevertheless, in the Sunrise video they assume a straight out departure and return to that field.

As I've done a fair bit of transition training in RVs, I'd just like to add that they vary dramatically in performance in this regard. Going from an RV-6 with 180 hp and CS prop to a -320 powered RV-9 with a FP cruise prop requires significantly different pitch angles. I can drop the 6 in easily with a tight pattern, whereas the 9 will float for-ev-er and I'll end up going around.

The same holds true with engine-out scenarios. The prop as a HUGE effect, especially in RVs, where the fixed-pitch props are typically biased heavily toward cruise performance.

To take this to the extreme, one of my favorite thing to do with providing a flight review to someone with a Pitts or Extra is to pull the power to idle along with the prop to low rpm on downwind and ask them to land. Even with an extreme slip the airplane will not slow down. It can transform a Pitts from a rock to a Schweizer instantly.

Every airplane is different. It's hard to remember that because they all look similar, but the prop has a big effect.

--Ron
 
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