Flaps during Engine Out Landing

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Got into a debate with a fellow instructor today on flap usage during emergency landings.

I teach and evaluate that once flaps are selected you cannot take them back out. My friend argues to take them out ,if you have sufficient height, when you notice that you are not going to make the runway.

Example: I pulled an engine on a student at 3000' 2 miles from the airfield. He immediately pulled 24* of flaps and held them through crossing midfield and downwind until turning base. He then realized that he wasn't going to make the runway so he retracted the flaps to 0*.

I wrote this up as part of his failure, however the main issue was that his base to final turn was at 45* in a skid about 200' off the deck. :yikes:

So what say yall? I've heard both sides of the argument on flaps.
 
I'd say just do what you need to do to make a safe landing. When I practice power off 180's sometimes I wouldn't even use flaps if it was a really windy day. Other times when it was more calm, I needed flaps to help me slow down and I added them sparingly once I knew I could make the runway with them.

Why was the student so eager to use flaps? If he's 2 miles out, he's got plenty of time to bleed off some airspeed to Vg or approach speed. Like I said before, I use flaps sparingly in my simulated engine out procedure. It does help that I train at an airport with a 6000 foot runway and if I float a bit it won't really make a difference.
 
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I was taught not to put them out until the runway is made. If I had done what your student did, my primary instructor would have raised them right then and said to leave them alone until later.

And he would have pointed out that a slip is almost as effective for losing altitude if needed, as is a tight spiral if you're over the only landable spot, and both can be removed/managed easier.

In some aircraft they don't have nearly as much effect on stall speed as in others, but you're flying Cessnas so get em out for the landing.

Less speed equals less energy equals less damage to the humans inside the spam can. But flaps aren't needed at all until the landing is assured.

His technique avoids the whole argument about whether you'll make it or not.

Most POHs agree and specify a specific flap setting for best glide, and that's where you want to be until you need to get rid of altitude and options. Best glide first. Flaps later. It's on the checklist that way, too.
 
Once the field is made....all the flaps come out (down). I want to stop ASAP and as slowly as possible.
 
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Once the field and landing are assured,flaps should be used so you don't overshoot the landing. That's how I was taught many years ago.
 
I teach people that they have "drag weapons" (retractable gear, flaps, prop, slip) that they can use if they're too high, and with the exception of the gear, none of them should be used unless you know you're too high. That usually means that gear comes out on the middle of the base leg or the turn to final, and flaps come out on short final if needed.

Now, having said that, context matters. A failure at cruise and a failure on the downwind leg are different, and how you handle them will be different. The bottom line is to get the airplane to fly the appropriate path to touchdown, and that you want to touch down with minimal energy.
 
Thanks.

Back on point...

1) If some distance out, realizing the error of your ways and retracting the flaps could make the difference in making the field or not. So I'd be against a hard and fast prohibition.

2) If the landing spot is a runway, full flaps is still a good idea, but hardly critical. If the landing spot is a literal field or road or otherwise off-airport, maximum flaps should be de rigeur to assure the slowest possible touchdown speed.

As an aside, I was reminded of the possibly apocryphal account of a Captain calling for "takeoff power". At which point the copilot took off the power! :rolleyes2:
 
I also was taught not to put flaps in until the runway/ field is made, but I do see your point about once you put them in you can't take them back out for loss of lift purposes.
 
FastEddieB said:
Thanks.

Back on point...

1) If some distance out, realizing the error of your ways and retracting the flaps could make the difference in making the field or not. So I'd be against a hard and fast prohibition.

2) If the landing spot is a runway, full flaps is still a good idea, but hardly critical. If the landing spot is a literal field or road or otherwise off-airport, maximum flaps should be de rigeur to assure the slowest possible touchdown speed.

As an aside, I was reminded of the possibly apocryphal account of a Captain calling for "takeoff power". At which point the copilot took off the power! :rolleyes2:
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I'd go with that.

Have ether if you two instructors (OP) had a full engine failure yet?
 
I agree with Tim. Flaps are a tool, and there are no hard-and-fast rules. If I deploy them too early and won't make the field, I will certainly retract some, if not all....depends on the situation.

Bob Gardner
 
Ryanb said:
I also was taught not to put flaps in until the runway/ field is made, but I do see your point about once you put them in you can't take them back out for loss of lift purposes.
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In aviation, be very careful about two words: "always," and "never." You did not use either, but "can't take them out" comes close.

Bob Gardner
 
ARFlyer said:
I teach and evaluate that once flaps are selected you cannot take them back out.
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Why not?
My friend argues to take them out ,if you have sufficient height, when you notice that you are not going to make the runway.
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Seems pretty reasonable if the alternative is crashing short of the target landing zone.

Example: I pulled an engine on a student at 3000' 2 miles from the airfield. He immediately pulled 24* of flaps and held them through crossing midfield and downwind until turning base. He then realized that he wasn't going to make the runway so he retracted the flaps to 0*.
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Wise decision.

I wrote this up as part of his failure,
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What "failure"? Did he not successfully land the plane in the designate area?

however the main issue was that his base to final turn was at 45* in a skid about 200' off the deck. :yikes:
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So if this happened for real, what would you have him do?

My argument is simple -- in an engine-failure situation, you use every tool you have to get the airplane safely on the ground. If modulating the flaps to manage glide path is one of those available tools, there is no reason not to use it. In my Tiger, where flaps do little to change lift coefficient but a lot to change drag coefficient, I like to set up so I turn final a bit on the high side, and then use flap setting on final to manage the glidepath from there, kind of like an S-3 Viking uses its DLC spoilers to manage glide path on final to the boat in order to avoid spooling the engines down so low a wave-off isn't possible.

BTW, on my most recent ride with an examiner, I was complimented, not criticized, for using flaps as a drag management tool on an engine-out approach to landing.
 
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Ron Levy said:
Why not?
Seems pretty reasonable if the alternative is crashing short of the target landing zone.

Wise decision.

What "failure"? Did he not successfully land the plane in the designate area?

So if this happened for real, what would you have him do?

My argument is simple -- in an engine-failure situation, you use every tool you have to get the airplane safely on the ground. If modulating the flaps to manage glide path is one of those available tools, there is no reason not to use it. In my Tiger, where flaps do little to change lift coefficient but a lot to change drag coefficient, I like to set up so I turn final a bit on the high side, and then use flap setting on final to manage the glidepath from there, kind of like an S-3 Viking uses its DLC spoilers to manage glide path on final to the boat in order to avoid spooling the engines down so low a wave-off isn't possible.

BTW, on my most recent ride with an examiner, I was complimented, not criticized, for using flaps as a drag management tool on an engine-out approach to landing.
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I was always that told by our former chief instructor. The reasoning is the lost of lift and glide distance during the reconfiguration of the wing.

He did the skid in real life. I almost took the controls from him because it slammed me against the door. I was more annoyed by the skid then the flaps. I told his CFI that I failed him on the lack of rudder control and not the flaps.

He had already tried the engine out earlier and fail to make the field. So I gave him a second chance.
 
ARFlyer said:
I was always that told by our former chief instructor. The reasoning is the lost of lift and glide distance during the reconfiguration of the wing.

He did the skid in real life. I almost took the controls from him because it slammed me against the door. I was more annoyed by the skid then the flaps. I told his CFI that I failed him on the lack of rudder control and not the flaps.

He had already tried the engine out earlier and fail to make the field. So I gave him a second chance.
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No one told the student to come in high and slip the snot out of the plane?

Or brining the plane in as high as possible and circling abeam the numbers?

Did anyone mention locking his touchdown spot in the windshield and what it means if the spot is getting higher or lower?
 
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ARFlyer said:
I was always that told by our former chief instructor. The reasoning is the lost of lift and glide distance during the reconfiguration of the wing.
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If they've been properly trained on pitch management during flap retraction, and they're not way slow of where they should be, that should not be an issue. Of course, that's somewhat a type-specific issue, too.

He did the skid in real life. I almost took the controls from him because it slammed me against the door. I was more annoyed by the skid then the flaps. I told his CFI that I failed him on the lack of rudder control and not the flaps.
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Was he slow enough that there was danger of a stall/spin? If not, I'd say uncoordinated flight is just another tool to use as appropriate in an engine-out situation.

He had already tried the engine out earlier and fail to make the field. So I gave him a second chance.
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I'd be more interested in why he failed to make the field the first time than what additional techniques he used the second time. However, if you gave him that extra chance, and he learned from his first try, and tried something different which worked, I'd be hard-pressed to fail him on the second attempt.
 
During my PP ride, I had pulled in the first notch of flaps abeam the numbers, then the DPE pulled the engine. I turned for the numbers, which put me in a strong headwind. I pitched down and reached for the flaps, the examiner pushed his knee agains the bar (Warrior). He said no, I wasn't sure what he meant. I said I was going to retract the flaps to reduce the drag as I was concerned about making the runway in the wind.

He moved his knee, I retracted the flaps, held my speed, turned toward the runway, and once I knew I was going to make the runway, I pulled in 2 notches, where I would normally have it for that strong of a crosswind. I landed succesfully and got to log my first PIC time.

I realized later that he thought I was going to add more flaps, which probably would have been bad.
 
Regarding use of flaps during a power-off approach (idle during training) I read as well as was taught to add flaps only after I am certain I will still be able to glide to my desired touch-down point even after adding flaps. If I'm not sure I'll make the desired touch-down point if I add flaps at a particular time/point, I will delay the adding of flaps until certain and continue at whatever the best glide speed is for flaps up (I think 65KIA for the older cessna with flasp up and 60KIAS with something like 20* of flaps down)

Once I do add flaps, I was taught to not retract flaps because retracting them will, naturally, suddenly increase my descent rate at that particular instance (assuming I'm already at best glide speed for flaps down) - and this might make me do the wrong thing of giving in to the temptation to reduce the sudden sink rate by pitching up before i regain increase airflow over the wings. Of course, trying to extend a glide by pitching up immediately after retracting flaps is a precursor to a possible stall. And that is why I was taught (from CFI and books) to not retract flaps after I deploy them.

But of course, If I'm just messing around, have plenty of altitude (and thus time) to regain airspeed back to best glide sped (for flaps up), I could retract the flaps and increase my down-pitch until i get back to my higher glide speed for flaps up.

So to me one very important thing is obvious: being able to make a good "call" (or guess) regarding the anticipated glide distance. If this is done well, then it is less likely I would be adding flaps prematurely and then cutting my glide distance too short, (or add flaps too late and risk overrun).

How do I estimate my gliding distance? I'm not one to give advice, but to help myelf do this, I often play a game while in the pattern (and conditions permit): I reduce power to idle on downwind abeam the numbers and instead of starting my abbreviated pattern to short final, I try to extend my pattern - while at idle - with the flaps fully retracted, for as far from the touchdown point as I think it is possible and still make it back to the runway; and all the time with flaps retracted.

When I start doing this, I would end up turning base and final too early, and I end up gliding with flaps up, farther past my selected touchdown point. So it seems I am underestimating the gliding distance (for some particular conditions). With practice, however, I've gotten to the point where I can extend my downwind, do coordinated turns to base and finals, and land just past the numbers with the flaps up.

So I do all of this to simply get used to the visual cues during a power-off glide, and help me manage/convert energy from its potential form (altitude) into kinetic. This will help me add flaps at the right time - not too early, not too late, and it's a fun game too (just be careful not to push it).
 
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Reedster said:
During my PP ride, I had pulled in the first notch of flaps abeam the numbers, then the DPE pulled the engine. I turned for the numbers, which put me in a strong headwind. I pitched down and reached for the flaps, the examiner pushed his knee agains the bar (Warrior). He said no, I wasn't sure what he meant. I said I was going to retract the flaps to reduce the drag as I was concerned about making the runway in the wind.

He moved his knee, I retracted the flaps, held my speed, turned toward the runway, and once I knew I was going to make the runway, I pulled in 2 notches, where I would normally have it for that strong of a crosswind. I landed succesfully and got to log my first PIC time.

I realized later that he thought I was going to add more flaps, which probably would have been bad.
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Good example of an instance when making a very quick decision to retract flaps during power-to-idle, was a good one (doesn't matter what I think though - the DPE must have liked it ha-ha).
 
iWantWings said:
Good example of an instance when making a very quick decision to retract flaps during power-to-idle, was a good one (doesn't matter what I think though - the DPE must have liked it ha-ha).
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I was definitely worried I had screwed up. I think he said 10 words to me the whole ride. I would have preferred not having No as one of them.
 
You land slower with flaps. So use them if you can. But don't use them if it means you wont be sure of making the field. So once you're sure you have the field made, put the flaps down.
 
FastEddieB said:
I was under the impression that would always be at zero flaps.

Am I wrong?
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Some airplanes have negative flap settings...don't know how that factors into best glide...

bobmrg said:
In aviation, be very careful about two words: "always," and "never." You did not use either, but "can't take them out" comes close.

Bob Gardner
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Just remember, there are absolutely no absolutes in aviation!
 
I thought some of the STOL (Pilatus Porter, and even a Maule or two) airplanes had flap settings of -6 or so degrees)
 
The context was DenverPilot's remark that most PoH's specify a flap setting for best glide. Since best glide is at L/D max I too would be very surprised if this was not zero (aircraft with negative settings excepted).

If flaps didn't decrease L/D my (not properly worked out) intuition is that they wouldn't steepen the approach.
 
Man I'm glad I'm part 61. I would never tell anyone I've failed them on anything. We talk about what they did right, what they did wrong, and what we'll do moving forward to reduce the wrong.

As to the skid mistake I see that all the time. I always tell people that if you want drag in the turn step on the sky. That'll give you the slip. Once the step on the sky thing clicks they no longer make that mistake.

As to adding and removing flaps. I don't care what they do long as it works. If they decide to add too much flap and they decide to remove some and we land safely I've got no complaints.
 
Retracting the flaps can effectively extend the glide IF you're high enough. Initially, you'll have to pitch down to maintain best glide, and you'll lose more altitude than you might think. It's fine at pattern altitude. It's not fine on short final.
 
denverpilot said:
I believe it's at negative flap in some gliders. ;)
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Thanks for that.

On point, I teach that the first thing to do after establishing best glide speed is to turn directly towards the nearest suitable airport or landing spot. Given enough altitude, aim for the center of the field. If you arrive above pattern altitude, circle down in a moderate bank, timing the last turn so as to roll out downwind abeam the intended point of landing at about 1,000'. From that point, one should be practiced enough* in power off approaches to make the rest routine and easy. Flaps should not be considered until the normal points in a power off approach.

The main problem is that pilots, in general, are terrible at judging glides from a long way out. I think most CFI's will attest to that. Hence the goal of turning the unfamiliar into the familiar.

*I'd recommend that about one in ten landings be a practice engine out from over the field at various altitudes. Quite simply, at a non-towered field just continue to the airport at cruise altitude, then pull the power over or nearly over the field. It's excellent practice and will not add mre than a tenth or two to the Hobbs.
 
bobmrg said:
In aviation, be very careful about two words: "always," and "never." You did not use either, but "can't take them out" comes close.
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+1. Three more words one should be careful with, IMO - "I was taught".
 
ARFlyer said:
I was always that told by our former chief instructor.
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There's the issue. Garbage in, garbage out. No offense Andrew, but you gotta verify what you've been told. Never take anything as fact/truth just because someone said so.
 
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