Putting flaps in during a turn

flyingron said:
Actually it's MUTE, as in silent. Moot meaning "without practical significance or relevance" makes not sense in this point.
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Yeah, I read too fast, I thought it was a reference to a moot point.
 
FastEddieB said:
Let me tell a little story…

First, the plane:

It’s a 1976 Cessna 172. 8,352 hours, used regularly as a trainer, but generally well maintained.

But on the left flap actuating rod, right adjacent to the jam nut, there’s a hairline fracture that would need a magnifying glass to see. Its the result of more than one overstress as a student has put down flaps above Vfe. The crack is about 3/4 of the way through the rod and about to let go. In fact, its going to fail on the very next flight, as the flaps go from 10º to 20º, and the split flap situation it causes will roll the airplane left at about 30º/second.
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So, did he learn to do a proper preflight after that?
 
"Cropdusters and specific cases aside", some night when you're circling/crunching around in a tight turn trying to keep the dimly lit runway in sight at about 300 feet off the ground and you're fast as you come around in the turn and...you ain't goin around. Much worse wx is coming and you're outta gas. Sudden and immediate use of flaps and/or slips can mean the difference between life and death.
...and don't tell yourself you'll never get yourself in that position.
I can think of 100 more.
 
I was taught attitude and airspeed is EVERYTHING during landing. If you're set up right, it shouldn't matter. I trained in a PA28 with manual flaps, so first set of flaps abeam the numbers, 2nd set during the turn from downwind to base, final set during the turn from base to final, ALL gradual deployment of course. Electric flaps worry me way more than manual flaps. I follow the level wing approach while using electric flaps.
 
Sounds like we have an interessting split in the discussion here. I'm glad I asked because the replies that followed were all enlightening!

My only thought is why not just wait till wings level to deploy the flaps? I've never counted how long a base turn takes but it can't be more than 7 seconds with the wings banked. In that time, how much could the speed increase or decrease in most simple trainers being flown correctly? I would not think much.

I would agree that asymmetrical flap deployment is extremely rare but I'd still not take the chance.
 
jspilot said:
Sounds like we have an interessting split in the discussion here. I'm glad I asked because the replies that followed were all enlightening!

My only thought is why not just wait till wings level to deploy the flaps? I've never counted how long a base turn takes but it can't be more than 7 seconds with the wings banked. In that time, how much could the speed increase or decrease in most simple trainers being flown correctly? I would not think much.

I would agree that asymmetrical flap deployment is extremely rare but I'd still not take the chance.
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If I'll be wings level before I need full flaps, sure, that doesn't always happen.
 
Why WOULD you put in flaps during a turn?

If you're paying attention to what you're doing, you know well ahead of time when you'll want flaps, so put them in before or after the turn and keep your eyes outside the cockpit to take advantage of all that sky around you that you're unblanking by moving the wings out of the way.
 
nosehair said:
Sudden and immediate use of flaps and/or slips can mean the difference between life and death.
...and don't tell yourself you'll never get yourself in that position.
I can think of 100 more.
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Ummm...

...I'm pretty sure I have the skill set to deploy or raise flaps in pretty much any attitude within the flap range - it's not like it's all that hard to do.

And I can slip with the best of them, foot to the floor straight or in a turn and come down like a freight elevator. In cropdusters even*.

But I honestly can't remember being in a situation where I HAD to deploy flaps in a turn, or the last time I did it. Though I can imagine emergencies and extreme situations where I would do so without hesitation - the remote possibility of split flaps would not even enter into the calculation.

I, personally, don't see the benefit of deploying flaps in turns, or the need in most circumstances, but if the technique works for you, have at it - it's extremely unlikely to ever make any difference at all.

*I have at least 100 hours in Cessna AgTrucks and AgHuskies, though all ferry flights. In any case, flown like that no need for flaps in turns. I'm sure pilots who actually dust crops have an entire skill set and bag of tricks I do not possess.
 
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SoloEqs said:
Why WOULD you put in flaps during a turn?

If you're paying attention to what you're doing, you know well ahead of time when you'll want flaps, so put them in before or after the turn and keep your eyes outside the cockpit to take advantage of all that sky around you that you're unblanking by moving the wings out of the way.
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Many times landing in a turn. I used to do it all the time when Long Beach tower would clear me for the option to turn abeam the tower to land mid field and get me in ahead of a line of 150s. As soon as they called I'd start a slipping left turn diving for the runway and rolling in full flaps all at the same time.
 
Ron Levy said:
Not in a stable turn, only when rolling in or rolling out. If one wing were producing more lift than the other, you'd keep rolling. Of course, if the ailerons are centered once you achieve desired bank angle, you may some rolling tendency into the bank due to unequal speed over the wings or dihedral effect, but we use a bit of aileron to hold the bank angle steady once established in the turn, and then both wings are creating the same amount of lift.

The change in pitch when rolled into a turn without back pressure is not due to one wing producing more lift than the other, but rather due to the reduction in vertical component of lift due to bank angle, and the aircraft's attempt to maintain trimmed speed.

The pitch change when banked is always going to be nose-down regardless of the initial pitch attitude (assuming no change in pitch force or trim setting is made).

Only way flap application creates a difference in lift when banked is if the flaps deploy asymmetrically.

No significant change in rudder required other than due to reduction in airspeed caused by increase in drag, and change in yaw balance due to increased power to keep the same sink rate with greater drag.

That's a perfectly fine technique.
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Thanks for the succinct response Ron! :)
 
If you are anywhere near Vfe, seems like putting them down in a turn could be risky because of the inertia putting more weight on the aircraft.

Banks are hard enough to keep coordinated, why would you want to complicate it?
 
SoloEqs said:
Why WOULD you put in flaps during a turn?

If you're paying attention to what you're doing, you know well ahead of time when you'll want flaps, so put them in before or after the turn and keep your eyes outside the cockpit to take advantage of all that sky around you that you're unblanking by moving the wings out of the way.
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I do it all the time. Several approaches I fly are VOR that commence over the VOR on the airport. Making the turn towards the FAF I begin configuring the aircraft to arrive on FAF in the landing configuration.

Honestly I've never heard this "don't move flaps in a turn" nonsense.
 
I don't remember any specific instruction regarding this in my past training other than knowing that Cessna flaps don't just have a possibility of failing at in opportune times, they WILL fail at inopportune times.

And then one night I finally had them stick at 40 during a touch and go in my own darned well-maintained airplane. %*+!£}]?£*++*% !!!

And every instructor's words came back to me in those two seconds of "WTF" as I assessed that I had remaining runway to land and stop on. So I did. And I got reminded why you always LOOK at Cessna flaps to confirm motion.

Haven't seen the split flap thing yet, but the assumption is that I WILL. In something. Someday.

Positive flying. If the thing is rolling and you don't want it to roll, STOP it. Don't sit there staring at it. Act.

Fly like things WILL break and be happy when they don't... Most of the fleet is old. Really old. Especially rentals.
 
ifconfig said:
Rod Machado talks about this here: http://www.aopa.org/News-and-Video/All-News/2012/May/1/License-to-learn.aspx
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Thank you for that link.

"One such mythtake revealed itself at a local FAA safety seminar when an attendee mentioned that he never extends flaps in a turn for fear of stalling."

Not one I've heard of before, and not the reason I preferred my students not to apply flaps in turns, but...

...he makes some good points.

Flaps do affect airspeed and trim and pitch required to hold a given airspeed.

It's easy for many of us to think, "Well, duh - and a pilot should know that and instinctively adjust for it, whether in a turn or not."

Of course.

But part of being an instructor is to initially makes things as easy as possible - students are not born knowing the effects of flaps and how to react to them with pitch and trim corrections.

So it makes sense to have them deal with flaps while they're not having to deal with the additional forces in a turn.

Now, Henning can, from midfield, slip while turning AND applying flaps all the while to begin a turning landing within a few feet of his intended point of landing. All to avoid following a few 150's on final and to save a tenth or two on the hobbs.

As an aside, so can I - so there!

But then there's that quote, something about superior pilots using their superior judgment to avoid having to use their superior skills.

And, as a further aside, I have found that the procedures I teach to students to make flying easier and safer tend to work across the board - regardless of the years and hours and superior skills a pilot may have.
 
txflyer said:
If you are anywhere near Vfe, seems like putting them down in a turn could be risky because of the inertia putting more weight on the aircraft.

Banks are hard enough to keep coordinated, why would you want to complicate it?
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How many G's are you pulling in the pattern?

Flap weight is the same whether deployed or not. Aerodynamic loads don't care what the aircraft weighs.
 
This thread is utter nonsense. Many of you must be snowed in and bored. ;)
 
This is kind of ridiculous :D

I prefer to wait until wings level before putting in flaps. However, since I usually attempt to fly a tight pattern, i'm generally never wings level on the base leg. That next notch of flaps usually gets put down while in a bank.
 
LandSickness said:
I was taught attitude and airspeed is EVERYTHING during landing. If you're set up right, it shouldn't matter. I trained in a PA28 with manual flaps, so first set of flaps abeam the numbers, 2nd set during the turn from downwind to base, final set during the turn from base to final,
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Your statement leads me to believe that the winds, temperature and humidity are always the same at your airfield and that you never have to vary the timing of anything.

I seriously doubt this is the case. Proper timing for flap deployment, turns, etc. in the pattern are variable and should be adjusted to meet the demands of that day's conditions.
 
timwinters said:
Your statement leads me to believe that the winds, temperature and humidity are always the same at your airfield and that you never have to vary the timing of anything.

I seriously doubt this is the case. Proper timing for flap deployment, turns, etc. in the pattern are variable and should be adjusted to meet the demands of that day's conditions.
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It's just more of the "I was taught" rote procedure mentality. It's hard for some to break away from that.
 
Here's a reason: because the "infinitesimal risk" is offset by the non infinitesimal benefit of having flexibility to do what's necessary to establish the plane on a stabilized approach. This is especially true for busy airports like the one I use where one never knows when the turn to base will occur...could be short, could be a 5 mile downwind. Also, some planes (e.g., Cirrus) are especially prone to even slight errors on final. Having the extra flexibility to deploy flaps when appropriate can help a lot....not always...but it's a nice added safety measure when needed.

FastEddieB said:
This came up recently.

It's how I was taught, and how I taught my students.

It's extremely unlikely that any given pilot will ever end up with a split flap condition.

But it does happen.

I've just never heard it clearly articulated what is to be gained by deploying flaps while turning. If there's even an infinitesimal risk, why not just wait?
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In electric flap airplanes I teach wings level, then mess with the flaps. They are students, they have enough on their plate as it is. I do explain why - because of the split flap condition - not because it's going to drastically change the dynamics of how the plane flies. In manual flap airplanes I don't worry about it as much. I initially teach wings level, then flaps, but as we get near the end of training, I start letting them add flaps during the turns so they get a feel for it.

When I'm flying, flaps go in whenever I feel they need to - and since I pretty much always fly a 180° dw-base-final (there is no leg on an arc) flaps are going in during the turn.
 
FastEddieB said:
Now, Henning can, from midfield, slip while turning AND applying flaps all the while to begin a turning landing within a few feet of his intended point of landing. All to avoid following a few 150's on final and to save a tenth or two on the hobbs.
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:confused: Why would you think it's to save a few tenths on the Hobbs?:confused:

It's for safety and doing tower a favor by getting my 100kt airplane out of a pattern filled with 150/2s doing 70. I don't slow below blue line until on final.
 
Turningfinal said:
This is kind of ridiculous :D

I prefer to wait until wings level before putting in flaps. However, since I usually attempt to fly a tight pattern, i'm generally never wings level on the base leg. That next notch of flaps usually gets put down while in a bank.
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I don't think anyone here has said "NEVER deploy flaps in turns", but that's become the straw man here.

My position? In general, and without good reason to do otherwise, I too "prefer to wait until wings level before putting in flaps".

I guess what's different is that my normal routine hardly ever mandates flaps in turns, so in general I just don't do it - out of habit. Even when called upon to do slam dunk tight finals, I usually have a moment or two between turns to deploy flaps.

But whatever floats your boat if fine. My students will be advised to avoid flaps in turns and the reason will be explained - it's never "because I said so!". Once they leave the nest they can accept or reject my advice and procedures as they see fit.
 
SoloEqs said:
Why WOULD you put in flaps during a turn?

If you're paying attention to what you're doing, you know well ahead of time when you'll want flaps, so put them in before or after the turn and keep your eyes outside the cockpit to take advantage of all that sky around you that you're unblanking by moving the wings out of the way.
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What if you have a mid field engine out, or have to do a short approach? You've really limited your options if you will only deploy flaps when the wings are level.
 
For perspective, I went back to the OP:

jspilot said:
I was always taught that putting flaps in during a turn( like down wind to base or base to final) was a bad thing to do and infact could jeopardize the safety of the flight.
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I will agree that that is overstated.

It's not, de facto, a "bad" thing, nor does it jeopardize the safety of flight in any significant fashion.

But I will continue for the rest of my career to try to avoid deploying flaps in turns unless absolutely necessary, or flying an aircraft type where it is SOP. And advise my students to do likewise*.

Beyond that, everyone will have their own rationales and comfort levels.

Fly safe!


*Full disclosure: I allowed my CFI to expire a couple years ago, and I'm currently flying Light Sport sans medical. I'm just waiting for the right time and motivation to get one or both back. But I am not currently instructing.
 
RotorAndWing said:
Please explain.
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MAKG1 said:
How many G's are you pulling in the pattern?

Flap weight is the same whether deployed or not. Aerodynamic loads don't care what the aircraft weighs.
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Banks are established with aileron and held with elevator. Like a climb, you're pushed down in your seat.

I guess you guys perform perfectly coordinated 1g turns. :confused: Vfe on mine is 120knots. So if I'm going 110knots, start a turn, and pull flaps, the actual weight/load on the wings could be exceeding Vfe was my point. I have manual flaps. So why is it harder to pull in a bank than it is level if the flaps are not seeing that load?

I'm not an engineer, but I did stay at a Holiday Inn Express one time. :goofy:
 
txflyer said:
Banks are established with aileron and held with elevator. Like a climb, you're pushed down in your seat.

I guess you guys perform perfectly coordinated 1g turns. :confused: Vfe on mine is 120knots. So if I'm going 110knots, start a turn, and pull flaps, the actual weight/load on the wings could be exceeding Vfe was my point. I have manual flaps. So why is it harder to pull in a bank than it is level if the flaps are not seeing that load?

I'm not an engineer, but I did stay at a Holiday Inn Express one time. :goofy:
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:confused: Why do you think that Vfe is a load factor issue rather than aerodynamic? If you are banking in a level turn and increasing load factor, unless you increase power, you will lose speed, not increase.
 
If you need flaps in the pattern you are in a descending turn and not adding load. I guess dragging it in under power and maneuvering to land on a sandbar or sometning would be an exception, and we all do that everyday.:rolleyes2:
 
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