When do you flap?

[Dean]

Last night I went flying with a friend of mine who is a CFI. ( Not the one I used for my PPL) We were doing night landings and as we entered downwind I set the flaps at 10 degrees, turned base and added 10 more and on final added 10 more. This was how I was taught during my PPL lessons. He suggested that I not add any flaps until I was on final, just in case I have an engine failure I would most likely make the runway. So my question is, How do you do it?

 

[Dave Krall CFII]

Last night I went flying with a friend of mine who is a CFI. ( Not the one I used for my PPL) We were doing night landings and as we entered downwind I set the flaps at 10 degrees, turned base and added 10 more and on final added 10 more. This was how I was taught during my PPL lessons. He suggested that I not add any flaps until I was on final, just in case I have an engine failure I would most likely make the runway. So my question is, How do you do it?

If you're maintaining the properly adjusted glide path and alter your pattern dimensions immediately, it shouldn't matter but it could be close.

That's how I was taught too and it's a fine place to start, with the addition that I employ in my training flights of dumping in various amounts of flaps including fully deployed at all phases of flight including the downwind since there's always some scenario in which it could happen.

 

[gismo]

Last night I went flying with a friend of mine who is a CFI. ( Not the one I used for my PPL) We were doing night landings and as we entered downwind I set the flaps at 10 degrees, turned base and added 10 more and on final added 10 more. This was how I was taught during my PPL lessons. He suggested that I not add any flaps until I was on final, just in case I have an engine failure I would most likely make the runway. So my question is, How do you do it?

The plane I fly (B55 Baron) requires different techniques than your light single, but I believe that you were taught this way because it minimizes the amount of trim change at any point in your pattern (and it gives you something to use the multiple angle preset positions on your flap switch). Using flaps before final does allow you to fly a lower speed and still have adequate stall margins, but you could get most of that by using the first notch of flaps on downwind before turning base and wait until final for the rest. No matter what you do, you will be exposed to being unable to reach the runway at some point in your pattern but the risk is pretty minimal. Prior to turning base, I think you could make the runway with no power provided you turned towards the end of the runway immediately with or without ten degrees of flaps. Somewhere along the base leg you will reach the "point of no return" and that point probably comes a bit sooner if you have 20 degrees of flaps deployed.

I don't see a big advantage either way (how you were taught vs all or most on final) but you will find that many more advanced aircraft only have three preset positions: Up, Approach, and Down. On those airplanes one typically selects approach flaps upon enterring the pattern (after putting the gear down if retracted) and full flaps somewhere on final.

 

[Bones]

I happen to believe its completely up to you. It all depends. Depends what aircraft your flying, what the conditions are, your speed, your altitude, the surrounding terrain, the weather, if you are flying an instrument approach or not, a non-precision appch or a precision approach.

Again I think there are a million ways to skin the aviation cat. As long as you understand the consequences and aerodynamics of putting those flaps out then I think its all up to you, your judgement and the situtation.
FLAP ON!

 

[Dave Siciliano]

A lot of folks take the position one shouldn't add full flaps until the runway is made. It would be embarassing and expensive to land short of the runway if one lost the engine if flaps could have made the difference. So, one can make the approach closer and have the flaps out earlier, or be prepared to raise the flaps if need be.

For me, where I fly and what I fly, I prefer to come in a little faster and above the normal approach path in case of engine loss. Approach flaps in the Baron until the runway is made; none in the A-36 until the runway is made; then flaps down.

If you're in an airport environment with faster traffic, it's nice to be able to keep the speed up a little until short final. I can't fly at blue line behind a lot of singles that have power in much less in a pattern with full flaps (blue line being over 110 knots in the P-Baron).

So, it all depends. You want to fly closer to the runway and a slower pattern, flaps earlier are fine. You want to fly a little farther out and a little faster, I'd wait on the flaps until closer in.

Just make sure you don't forget them if they are needed. Most of us can land at most airports without 'em; we just touch down faster and roll farther. It's not normally preferable, but, unless you're going into a short field, not critical.

Best,

Dave

 

[Ed Guthrie]

Last night I went flying with a friend of mine who is a CFI. ( Not the one I used for my PPL) We were doing night landings and as we entered downwind I set the flaps at 10 degrees, turned base and added 10 more and on final added 10 more. This was how I was taught during my PPL lessons. He suggested that I not add any flaps until I was on final, just in case I have an engine failure I would most likely make the runway.

Ask your CFI friend to explain to you how he would extend the glide distance/reduce the drag of a clean configured, fixed-gear, fixed-pitch prop aircraft when the engine dies. Then ask him how he would extend the glide distance/reduce the drag in the same situation, but flaps extended.

Then ask him why he thinks the first is the preferable configuration if he's worried about making the runway.

 

[poadeleted20]

Did you ask him if he refuses a tower instruction to extend his downwind on that basis? Or whether he does not ever fly outside gliding range of an airport? I do not understand the apparently widespread belief that aircraft engines become suddenly more likely to fail when in the landing pattern.

Personally, in my Tiger, I generally add 1/3 flaps on downwind, and full flaps on base -- otherwise, it just doesn't have enough drag to come down.

 

[Henning]

Last night I went flying with a friend of mine who is a CFI. ( Not the one I used for my PPL) We were doing night landings and as we entered downwind I set the flaps at 10 degrees, turned base and added 10 more and on final added 10 more. This was how I was taught during my PPL lessons. He suggested that I not add any flaps until I was on final, just in case I have an engine failure I would most likely make the runway. So my question is, How do you do it?

For me it depends on the airplane, some you need to start really slowing them down early, some you can just pull the throttles and dump in the gear and/or flaps in the last 200' on final. If you're on downwind, you should have the field made with one notch of flaps regardless, same for base with two.

 

[Anthony]

In my Tiger, abeam the numbers, right after I reduce power. If I have an engine failure I can turn towards the runway and make the field. I fly a pretty tight pattern.

 

[Dave Krall CFII]

Did you ask him if he refuses a tower instruction to extend his downwind on that basis? Or whether he does not ever fly outside gliding range of an airport? I do not understand the apparently widespread belief that aircraft engines become suddenly more likely to fail when in the landing pattern.

Personally, in my Tiger, I generally add 1/3 flaps on downwind, and full flaps on base -- otherwise, it just doesn't have enough drag to come down.

There may be a statistically higher probability of pattern engine failure from the point of power reduction on the downwind, linked to an increased failure rate of engines while in any type of descent phase of flight. I'd have to get into the Nall report again more than I have the time to confirm or deny this not uncommon conclusion.

 

[ScottM]

There may be a statistically higher probability of pattern engine failure from the point of power reduction on the downwind, linked to an increased failure rate of engines while in any type of descent phase of flight. I'd have to get into the Nall report again more than I have the time to confirm or deny this not uncommon conclusion.

I'd be interested in your investigation. It would seem that during power reductions there would less of a chance of engine failures as apposed to power increases, such as soon after take off as that is when the most stress is being placed on the engine. But I am guessing as well.

 

[gismo]

There may be a statistically higher probability of pattern engine failure from the point of power reduction on the downwind, linked to an increased failure rate of engines while in any type of descent phase of flight. I'd have to get into the Nall report again more than I have the time to confirm or deny this not uncommon conclusion.

Reducing power should actually extend the time before failure of a marginal engine. AFaIK the only reason that power loss might be more likely in the pattern than elsewhere is that the closer you get to landing the greater the chances for fuel exhaustion.

OTOH, there probably is an increase in risk of aircraft damage and personal injury as a consequence of engine faiilure at pattern altitude vs cruising altitude.

 

[Dave Krall CFII]

I'd be interested in your investigation. It would seem that during power reductions there would less of a chance of engine failures as apposed to power increases, such as soon after take off as that is when the most stress is being placed on the engine. But I am guessing as well.

Lance & Scott, I recall hearing that any change in power (temp changes/expansion/contraction ?) will increase failure probability with power applied for takeoff being second in frequency to power reduction for descent. Someone will delve into a few years Nall Reports and confirm or deny no doubt but, I've gotta go fly right now.

I guess I'll use the same power setting for all phases of flight so that this will not be an issue for my flights !
Yeah, that's the ticket. Good brakes, too.

 

[RotaryWingBob]

Lance & Scott, I recall hearing that any change in power (temp changes/expansion/contraction ?) will increase failure probability with power applied for takeoff being second in frequency to power reduction for descent. Someone will delve into a few years Nall Reports and confirm or deny no doubt but, I've gotta go fly right now.

I guess I'll use the same power setting for all phases of flight so that this will not be an issue for my flights !
Yeah, that's the ticket. Good brakes, too.

I suspect that's an OWT, Dave. If it were true, piston helicopters would be falling out of the sky in record numbers, because every landing requires frequent use of the collective, and each collective adjustment makes the manifold pressure change to adjust for the pitch change (so that rotor rpm stays constant).

Likewise, hovering in windy conditions usually requires collective movement to maintain hover height as well.

When do I flap? Twice in each rotation of each main rotor blade -- once up, once down

Ooops. More often than that -- twice in each rotation of each tail rotor blade as well

Oh, ok, you meant airplanes

I usually fly a pretty tight pattern, but don't add the last (40 degree) notch in the Cherokee until I know I've got the runway made, and then I pretty much do a dead stick landing every time.

 

[poadeleted20]

I recall hearing that any change in power (temp changes/expansion/contraction ?) will increase failure probability with power applied for takeoff being second in frequency to power reduction for descent.

I've heard people say that for over 35 years, but I've never in those 35 years seen data that proves it.

 

[jesse]

I guess I can't really say when I apply flaps.

It depends. I actually deal with controlled airports more then uncontrolled.. Which means pretty much all my landings are base to final or straight in landings.

I also tend to vary the amount of flaps I use based on the circumstances, and aircraft. I guess it's usually just part of my before landing checklist:

Carb heat as required
Gas on
Undercarridge down
Mixture Rich
Prop forward on short final
Flaps as required

...I say that in every plane I fly. Though I don't fly a plane where all of them apply. The complex plane I fly is fuel injected for example. But I still say it.
If I have passengers that have flown with me a few times, Cool, I'll say it outloud over the intercom. If I am taking someone flying for the first time I always push my microphone over a little bit so I don't trigger it. I have a habit of talking to myself outloud when landing..and sometimes what I am saying might scare them:

"we are too high, too fast.... bring on the slip" or something like that.

or
"winds from the left. strong as hell"

I quickly discovered passengers do not want to hear that sort of stuff


Usually if I guess I'll start dumping flaps when I get the airplane into the white arc..the gear usually comes down when I am in it's extension speed range. They are nice for slowing you down, Plus if they aren't going to come down I want to know about it as early as possible.

 

[Henning]

There may be a statistically higher probability of pattern engine failure from the point of power reduction on the downwind, linked to an increased failure rate of engines while in any type of descent phase of flight. I'd have to get into the Nall report again more than I have the time to confirm or deny this not uncommon conclusion.

Doesn't sound like it should be, typically one comes into downwind with a lot of energy to burn off, and I'd think most often the problem with an engine at that point would be a matter of fuel mixture being forgotten, and that should be able to be fixed rather quickly, long before the prop quits spinning, unless I'm reading that wrong and they don't mean that descent to downwind transition is the most failure prone of the flight, but rather the most failure prone point of descent/landing phase only.

 

[AirBaker]

I typically don't add in flaps until I was abeam the numbers downwind.

Hopefully if you lost the engine in the pattern, you'd get a few seconds of ugly noises first to tell you to turn towards the runway anyways...

 

[spiderweb]

Last night I went flying with a friend of mine who is a CFI. ( Not the one I used for my PPL) We were doing night landings and as we entered downwind I set the flaps at 10 degrees, turned base and added 10 more and on final added 10 more. This was how I was taught during my PPL lessons. He suggested that I not add any flaps until I was on final, just in case I have an engine failure I would most likely make the runway. So my question is, How do you do it?

I think that this is just another example of needless worry. Think about it: First of all, engine failures are rare. Second of all, how often does an actual engine failure occur somewhere between abeam the numbers but before final, in those 60 seconds or so?

I'm all for experimenting and practicing different scenarios, but your friend/CFI's recommendation just isn't based on anything scientific. If you are abeam the numbers at 1,000' AGL, you can make the runway, period. OTOH, if you want to wait to add flaps until final just because you prefer to do it that way (maybe you like don't like to break up adding flaps into three stages), that's up to you. Personally, I like the way you were taught, because you don't need any trim changes if you us the correct power settings.

I like to have an SOP for standard scenarios. For example, on an ILS or at the end of an NPA, I fly flaps 0 until DA and I have the runway. Then, I go straight to my final flap setting of choice. My reasoning here is that if I never see the runway, I go missed with no drag. You can argue for flying with 10 or 15 degrees, too--there are fine arguments either way, but the point is to have an SOP you feel comfortable with, and stick to it.

Right now, just do what you do, and don't change anything. You have an exam coming up, right?

 

[Bob Bement]

With my 182, with manual flaps, I usually apply two notches on down wind abeam of my touchdown spot. I put the other two notches on when I am on base. I don't make a long pattern out of it so I don't have to add any power on final. In a strong cross wind I don't use all flaps. I would use only two notches alltogether. It works for me. 1960 hours total. about 1100 hours in my 182. It depends on the instructor.

 

[RogerT]

So my question is, How do you do it?

Flaps are just another flight control. I add them when I need them
for the conditions .. not at any particular point.

 

[poadeleted3]

I do it a couple ways.

Usually, I do it as you describe... In a Skyhawk, I reduce the power abeam the numbers, slow, and add the first 10 degrees. Turn base, and add the second 10. Turn final and go to 30 degrees. If I'm flying an older one, I'll add the final 10 degrees for the full 40 when I've got the runway made. If I'm flying into a short, obstructed strip I add the full 30 or 40 degrees when I'm abeam the numbers, and slow to final approach speed before I turn final. It's how I was taught when I was flying into a field that required flying around a hill with trees just off my wingtips on short final, and it's still how I do it. Reason being, when I'm flying into such a field, once the flaps are in, it's just one less thing to do.

When I'm flying a Tiger, I also add full flaps abeam the numbers. Again, it's how I was taught, and the flaps aren't terribly effective. I'd just as soon set them and forget them.

 

[poadeleted20]

When I'm flying a Tiger, I also add full flaps abeam the numbers. Again, it's how I was taught, and the flaps aren't terribly effective.

I wouldn't quite say that -- they're very effective at adding drag and lowering the pitch attitude at low speed (y'gotta be careful of skagging the tail when landing with no flaps in a Grumman), just not much at increasing max coefficient of lift/lowering stall speed.

 

[ted6357]

I wouldn't quite say that -- they're very effective at adding drag and lowering the pitch attitude at low speed (y'gotta be careful of skagging the tail when landing with no flaps in a Grumman), just not much at increasing max coefficient of lift/lowering stall speed.

Ron, what model Grumman are you referring to here? When you say 'skagging' the tail, do you mean dragging the tail on the ground?

Also, in the case of a flapless landing on this model or similar designed model, how would you avoid skagging the tail, perhaps aim for a three point landing?

 

[poadeleted20]

Ron, what model Grumman are you referring to here?

All the light singles (AA/AG-1/5 series).

When you say 'skagging' the tail, do you mean dragging the tail on the ground?

Yes.

Also, in the case of a flapless landing on this model or similar designed model, how would you avoid skagging the tail,

Same way you do in a short-leg Cirrus -- careful control of touchdown attitude and no abrupt aft elevator inputs in the flare.

perhaps aim for a three point landing?

If you mean a landing with simultaneous touchdown on all three wheels, definitely not -- that's real trouble in a Grumman.

 

[RyanB]

I do the same as OP. Let me ask this, say i have 30 flap on final and have an engine failure, would you reduce the flaps to 10 degrees to reduce drag but still not reduce lift by taking away all flaps? Or would you leave the flaps down?

 

[Hank S]

Flaps are simple, just another flight control to use as required.

I learned in two Skyhawks, one each with 30° and 40°. Abeam the numbers, Flaps 10°; on base leg, Flaps 20°; on final, adjust flaps as needed to land where I want to land.

The Mooney us even easier. On downwind, Flaps to Takeoff; abeam point of intended landing, Gear Down; on final, Flaps as desired to land where I want to land.

Generally speaking, the stronger the wind is blowing, the less flaps I use. Also, I've learned that my short body Mooney lands well with partial flaps, but F models do better with full flaps. Then again, the F I flew had three position flaps, while my C has three markings but is infinitely variable, just hold the lever while it moves to wherever I want it to be.

 

[poadeleted20]

I do the same as OP. Let me ask this, say i have 30 flap on final and have an engine failure, would you reduce the flaps to 10 degrees to reduce drag but still not reduce lift by taking away all flaps? Or would you leave the flaps down?

What are you flying? How far out are you? How high are you? What's your airspeed?

In some cases, you aren't going to make the runway no matter what you do, so a controlled crash short of the runway at minimum speed (i.e., using flaps) is better than a controlled crash short of the runway at a higher speed. In some cases, retracting the flaps may result in sudden great sink or even a stall. In other cases (especially Grummans), retracting the flaps may increase your glide distance at the same speed (i.e., they are essentially drag brakes, not lift enhancers). IOW, it's all situations with no single "canned" answer.

 

[Henning]

I do the same as OP. Let me ask this, say i have 30 flap on final and have an engine failure, would you reduce the flaps to 10 degrees to reduce drag but still not reduce lift by taking away all flaps? Or would you leave the flaps down?

Are you single engine or twin? Not many SE pilots I know have themselves in a position to make the runway regardless of flap position if the engine dies anywhere short of the threshold, therefore I would recommend leaving in full flaps to reduce my energy to dead minimum on impact.

 

[brcase]

Last night I went flying with a friend of mine who is a CFI. ( Not the one I used for my PPL) We were doing night landings and as we entered downwind I set the flaps at 10 degrees, turned base and added 10 more and on final added 10 more. This was how I was taught during my PPL lessons. He suggested that I not add any flaps until I was on final, just in case I have an engine failure I would most likely make the runway. So my question is, How do you do it?

Depends a bit on the plane. I will often add the 1st notch of flaps on downwind since the 1st notch usually has be biggest effect on trim, usually slower which is what I usually want to do any way. After trimmed for approach I add flaps as needed.
I think many CFI's over simplify the use of the flaps. Things like use all the flaps that is what they are there for. It uses less runway and less wear and tear on the airplane, never mind that you are landing on a 3000 foot runway and only need 1000 or that you touch down at 45 instead of 50. (5 mph difference) Or that you could touch down 5mph slower by just raising the nose higher before touchdown.


Then on Flight Reviews I see things like pilot adding flaps on emergency procedures just because the always do. Then they can't make it to the runwayt. Or pilots that can't fly in the ground effect without ballooning because they always come in slow and draggy and never actually fly in ground effect.

Do yourself a favor and learn how to use the flaps as a tool and not just put them down because they are there.

Brian

 

[Brad Z]

You know you guys are replying to a 9 year old question, right?

The OP hasn't been here since July.

 

[brian]]

Flaps are the last thing I do on final
100 mph downwind
Select fullest tank
Prop highest rpm
Full rich
Cowl flaps
Drop gear abeam the numbers
90 mph to base
80 mph base
70 mph+ wind on final
Full flaps once I have the runway (takes forever for the flaps and gear on an old Bo)
Puffs (prop, under, flaps, flaps, switches)

 

[upstateny]

For me, he major factor is - am I at an uncontrolled field where I get to fly a "normal" pattern, or a towered field where they might send me out to East Jesus on the downwind before clearing me to land. If the former, 10 degrees abeam the numbers, 10 degrees on base, 10-20 degrees on final. If the later, wait until I'm on final unless the base turn is at a reasonable distance.

 

[RyanB]

You know you guys are replying to a 9 year old question, right?

The OP hasn't been here since July.

I didnt even notice the date when i saw this thread, LOL, wonder how it got brought back up in the feed

 

[Jim Logajan]

Ron, what model Grumman are you referring to here? When you say 'skagging' the tail, do you mean dragging the tail on the ground?

Also, in the case of a flapless landing on this model or similar designed model, how would you avoid skagging the tail, perhaps aim for a three point landing?

 

[Cpt_Kirk]

2005... that's almost a decade.

Most of you should feel pretty old.

 

[Cpt_Kirk]

In regards to the OP of the past, I flap when I want to flap, if I want to flap.

 

[Neal Howard]

In the RV-6 I put it the first portion of flaps after slowing to Vfe abeam the numbers, and full flaps after turning base. It a formula that's worked very well for my plane so I stick with it. I fly a tight enough pattern to always make the runway and often throw in a bit of forward slip on final to help bleed off some altitude.

 

[weilke]

2005... that's almost a decade.

Most of you should feel pretty old.

One of these days someone will reply to a thread that has been dormant as long as they have been alive.

I have seen people trying to start an argument with someone who had passed away a while ago.

 

[flyingron]

It really depends on what kind of flaps you have. The PA-38 I recall doesn't do much for lift or stall speed. I dropped them only to get a steeper flight path (and only if I had the field already made power off, the very low wings on the PA-38 gave a nice cushion and there was never any need to carry power into the flare).

The original Navion only had two flap positions full up and full down (37 degrees). I'd not drop the Navion flaps unless I had the field made. The angle of descent with the power off and full flaps in the Navion is startling.

My Navion has a modification that allows me to stop the flaps between full up and full down. They're fowler flaps not unlike the Cessnas. I put out ten degrees with the gear (typically on downwind or at the FAF). I'll typically add the rest when I have the field made or maybe some more on base if I'm close in and high.

I regularly use half flaps on takeoff (this is the short field strategy). With the increase in horsepower on my plane, climbing steeper keeps you from exceeding the gear operating speeds too quickly.