Dropping flaps while in a turn

Pilawt said:
There's a 50% chance that your turn will be in the opposite direction of the effect of the flap asymmetry -- in which case you'd have more time to react than if you were straight and level.

:stirpot:
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Yep. This silly issue exists purely in the realm of fodder for arguing on the internet about utterly unimportant things.
 
Theboys said:
Hardest habit to break is pulling flaps up on rollout to increase braking. If everybody would just put wheels up switch in same place or maybe have cover over it.
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In all but a few old planes, the gear switch has a vertical wheel on it, the flap switch has a horizontal flap on it. It can't be made much more fool proof.
 
Pilawt said:
There's a 50% chance that your turn will be in the opposite direction of the effect of the flap asymmetry -- in which case you'd have more time to react than if you were straight and level.

:stirpot:
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Absolutely. :) Nothing like 50% chance of an infinitesimally small probability that the asymmetrical flap deployment occurs in the same direction of the turn, lol. It's a solution in search of a problem. Not saying it isn't prudent wait until straight and level to deploy flaps, but if I were needing more flaps in the middle of a turn I wouldn't hesitate to deploy them.
 
Ron Levy said:
...but a habit you really do want to break. If you check the POH numbers, you'll see that pretty much every light plane (especially singles) has a significantly longer takeoff run than landing run. So, if you land on a runway so short you need to retract the flaps to have enough braking to stop in the available distance, the plane is probably not leaving again other than on a flat-bed truck. Choose appropriate runways and keep your landing proficiency up to par, and the issue doesn't arise. Hence, no need to touch anything other than the flight controls and brakes during rollout until you clear the runway and can stop and do it all without distracting yourself from maintaining control of the aircraft on rollout (said loss of control being one of the leading causes of landing accidents).
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Reading the POH is good. Example is the Beech BE23/24 series that has this placard "raise flaps to increase brake effectiveness", and the procedure is also discussed in the POH.

In the 23/24 series with full flaps the wheels have a tendency to lock up, raising the flaps on roll out gives better braking.
 
I usually roll inverted and then deploy the flaps.
 
I deploy flaps all the time while the ELEVATOR is turning the aircraft ... :stirpot:
 
Pilawt said:
The point is well-taken, of course. But I think the more common circumstance is hearing right after touchdown at a big airport, "Skyhawk XXX, traffic is a Gulfstream on a half-mile final, expedite off the runway at intersection Charlie; contact ground off the runway ..." (and intersection Delta is 3,500 feet further down the runway). Will I really not touch the flap handle in my 172 today because it might cause me to accidentally raise the gear in the unlikely event that I ever fly a retractable again?
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If you're at an airport that big, you don't need the flaps up to stop, and if you can't make Charlie without doing something exceptional, that's the controller's problem, not yours. Yeah, it's nice to help the controller, but if they don't tell me until after I land they want me off at Charlie, that's a problem they created for themselves and I'm not doing anything precipitous to help them out of the hole they dug for themselves.
 
RoscoeT said:
What I've never understood about the split-flap argument is that if you hit the jackpot and get a split flap during a 20-30 degree banked turn, and are unable to control roll well enough to return to wings level flight, then it stands to reason that you will also be unable to control roll if you get a split flap in level flight.
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If that happens in cruise, you have a lot of altitude available to turn into extra speed to get more aileron effectiveness. If it happens turning final at less than 400 AGL, your options are a lot fewer. Now, I'm not saying I think this is a valid argument, but it's what I was told when I was a Student Pilot, and I present it merely to answer the original question of why people say not to extend flaps while turning in the pattern.
 
RotorAndWing said:
Reading the POH is good. Example is the Beech BE23/24 series that has this placard "raise flaps to increase brake effectiveness", and the procedure is also discussed in the POH.

In the 23/24 series with full flaps the wheels have a tendency to lock up, raising the flaps on roll out gives better braking.
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That may be true, but does it make enough difference in landing roll if you don't hit the brakes that hard that you would not stop on a runway long enough to take off again? Somehow, I doubt it, although I only have a dozen or so flights in the BE23/24 types. OTOH, I've seen too many accident reports where someone inadvertently retracted the gear on landing, and I think in the long run it's better to leave the flaps alone until the airplane is slowed and well under control so you can a) be sure you're grabbing the right handle, and b) keep flying the plane through the landing and roll-out.
 
Ron Levy said:
That may be true, but does it make enough difference in landing roll if you don't hit the brakes that hard that you would not stop on a runway long enough to take off again? Somehow, I doubt it, although I only have a dozen or so flights in the BE23/24 types. OTOH, I've seen too many accident reports where someone inadvertently retracted the gear on landing, and I think in the long run it's better to leave the flaps alone until the airplane is slowed and well under control so you can a) be sure you're grabbing the right handle, and b) keep flying the plane through the landing and roll-out.
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Even light braking in the BE23/24 can cause brake lock up with the flaps down, hence the POH and the placard as required by the TCDS.
 
Ryanb said:
I have been taught "wait to extend flaps until you are level" so for example, if im in the pattern and i put 10 degrees down on downwind and im in the turn to base i should wait until i roll out of the turn to put the next notch of flaps in. Does this really effect aerodynamics? Do you have to wait to be level to put flaps in? This is flying a 152/172
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The airplane does not know its in a turn.
Flaps, gear, turn, why not?
 
Pilawt said:
The point is well-taken, of course. But I think the more common circumstance is hearing right after touchdown at a big airport, "Skyhawk XXX, traffic is a Gulfstream on a half-mile final, expedite off the runway at intersection Charlie; contact ground off the runway ..." (and intersection Delta is 3,500 feet further down the runway). Will I really not touch the flap handle in my 172 today because it might cause me to accidentally raise the gear in the unlikely event that I ever fly a retractable again?
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Tower, unable, I'm too fast for the turn without skidding tires.
Tower screwed the sequencing and the GII does a go around.
 
hindsight2020 said:
Back in my BUFF days our Tech Order (military version of the POH) restricted us from raising flaps in a turn. Since the flap travel stop-to-stop took 60 god damned seconds either direction (w/ both flap motors operative, 120 seconds with just one) ,if ATC gave us a turn as part of the departure, you had to stop the flap travel and continue to fly part-flaps. Flap overspeeds abounded as a result. Dummies.

Stupidest lowest common denominator restriction I've ever encountered in my pro life. And yes, the flap indicator had dual needles to identify flap asymmetry, so there's no excuse really. Ironically, dropping flaps in a turn was perfectly OK to them. Which tells me the restriction came about due to ham hands stalling the airplane by overbanking with retracting flaps, which granted, makes zero difference on a light piston plane, but does affect things on an airplane whose effective wing area increases by 40% due to simpleton flap deployment.

If changing flap settings in a turn saturates your basic aircraft control, you need more practice. Keep at it.
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Those flap sections were larger than the wing on some Cessnas.

"TIZ"
B-52G, 596BMS, KBAD
1985-1987
 
RotorAndWing said:
Reading the POH is good. Example is the Beech BE23/24 series that has this placard "raise flaps to increase brake effectiveness", and the procedure is also discussed in the POH.

In the 23/24 series with full flaps the wheels have a tendency to lock up, raising the flaps on roll out gives better braking.
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A lot of flat spotted tires on those Beeches.

Standard student instructor interchange.
Student hits brakes, instructor yells, "Get off the brakes!" as he drops the flap handle.
 
Funny thing, I was taught by my primary instructor to drop flaps in the base and final turns. It was years before I knew this was even a controversy.
 
ateamer said:
Why would asymmetric flaps be worse in a turn than in level flight?
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Assume an asymetric flap deployment causes a 30 degree bank in straight level flight. Then assume you are already in 30 degrees of bank manuvering close the the ground at 75 KIAS as a student.
 
I usually avoid braking lol. Seriously, it has to be a less than 2000' runway to require any heavy braking, but I put my wheels on the threshold, not 1000' down the runway.
 
Henning said:
I usually avoid braking lol. Seriously, it has to be a less than 2000' runway to require any heavy braking, but I put my wheels on the threshold, not 1000' down the runway.
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I wish the 337 was this way. It just rolls and rolls and rolls. I can't eat up 3,000 feet without thinking about it. My wheels are down within 500 feet, flaps come up, and it keep the nose wheel off as long as possible.
 
Cpt_Kirk said:
I wish the 337 was this way. It just rolls and rolls and rolls. I can't eat up 3,000 feet without thinking about it. My wheels are down within 500 feet, flaps come up, and it keep the nose wheel off as long as possible.
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:confused:You must be landing way too fast or always real heavy. I have flow the 337 (well, O-2) and I had no problem with landing short unless I was at gross, and even then 3000' with light braking no worries. What speed are you coming across the threshold at?
 
madtrader said:
Funny thing, I was taught by my primary instructor to drop flaps in the base and final turns. It was years before I knew this was even a controversy.
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So what did you do when you had a straight in approach??
I think they should teach it based on altitude: @1000, @800, @600, then you will be stabilized for the last 500.
 
teejayevans said:
So what did you do when you had a straight in approach??
I think they should teach it based on altitude: @1000, @800, @600, then you will be stabilized for the last 500.
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But when would I put in my final notch?

As with almost all things in aviation...it depends...no hard and fast rules work for all circumstances.

I don't worry about elevation or what leg I'm on when deploying flaps.

When flying a standard pattern, I chop the power abeam the numbers and put in one notch then trim for 70 mph.

When when I turn base I look at the runway and gauge how high I am. I decide to put in the second notch based on the sight picture.

Then when I turn final I look at the runway again and decide when to put in the third notch. It may be immediately, it may be later and, hell, I may have put it in before turning final if I was high on base.

The fourth notch is put in when the runway is assured (and if there's not too much crosswind).

I seldom consult the altimeter in the pattern after I chop the power abeam the numbers.

Every trip around the pattern is different when the wind is blowing in these Southern Missouri hills. I remember a recent day at my home drome. There was a 15 kt wind pretty well aligned with the runway, I turned final and I was on an up elevator. I kicked the plane into a full deflection slip and it still wouldn't descend. It just hung there at about 400' above the runway all the way to the threshold.

So I went around.

On the next attempt, I turned final expecting another up elevator. But no...I was on a down elevator this time and had to add significant power to make the runway.

So...

...it depends.
 
Sac Arrow said:
Unless you really botched your pattern I don't know why you would need to put them down in a turn, although I doubt it would be harmful. Just remember your stall speed does increase in a bank though.
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but flaps reduce stall speed right?
 
madtrader said:
Funny thing, I was taught by my primary instructor to drop flaps in the base and final turns. It was years before I knew this was even a controversy.
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Me too! Then it morphed into "Drop the flaps when you need them" regardless of turning or not.

I was being checked out in a rental plane in FL and dropped them in a turn. The instructor got all huffy about it. I didn't argue. Her plane, her rules.
 
Ron Levy said:
...but a habit you really do want to break. If you check the POH numbers, you'll see that pretty much every light plane (especially singles) has a significantly longer takeoff run than landing run. So, if you land on a runway so short you need to retract the flaps to have enough braking to stop in the available distance, the plane is probably not leaving again other than on a flat-bed truck. Choose appropriate runways and keep your landing proficiency up to par, and the issue doesn't arise. Hence, no need to touch anything other than the flight controls and brakes during rollout until you clear the runway and can stop and do it all without distracting yourself from maintaining control of the aircraft on rollout (said loss of control being one of the leading causes of landing accidents).
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Obstacle on final or displaced threshold? Why would raising the flaps after touchdown (or slightly before) be an issue for a proficient pilot be bad? Habits are mostly bad though, situations change, so I don't see it as something that ought to be a habit.
 
ebetancourt said:
Obstacle on final or displaced threshold? Why would raising the flaps after touchdown (or slightly before) be an issue for a proficient pilot be bad? Habits are mostly bad though, situations change, so I don't see it as something that ought to be a habit.
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Right above -- but not on -- the pavement is the one place where I don't play with flaps. It can make abrupt changes in track, and will certainly place the airplane out of trim.

Obstacle clearance is done by pulling power to idle when clearing the obstacle, and can be steepened by a somewhat slower approach speed. Even a 172 will obviously steepen the approach when pulling power from 1500 to idle, especially at full flap. Works well even with redwoods around.
 
Pilawt said:
Guess that's where we differ. I don't regard raising flaps an "exceptional" or "precipitous" act in that context.
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If the difference between making that turn and not is raising the flaps, I consider that "precipitous". Maybe that's just the difference between my tolerance of risk and yours, but that's what I think. And while I've seen a lot of folks come to grief on landing as a result of doing something abnormal or hasty, I've never seen a pilot written up for a Pilot Deviation for responding "Sorry, unable" to a request like that by a controller at that point.
 
BillTIZ said:
A lot of flat spotted tires on those Beeches.

Standard student instructor interchange.
Student hits brakes, instructor yells, "Get off the brakes!" as he drops the flap handle.
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Doesn't happen with me, since I teach "heels on the floor" until you make a conscious decision to commence braking, and then only gingerly to test them at first. Where you run into trouble is when folks get their toes up on the brakes even before touchdown, and that doesn't change for Beech versus Cessna versus Piper versus Grumman versus Cirrus versus Diamond versus :dunno:.
 
Ron Levy said:
"heels on the floor" until you make a conscious decision to commence braking, and then only gingerly to test them at first. Where you run into trouble is when folks get their toes up on the brakes even before touchdown, and that doesn't change for Beech versus Cessna versus Piper versus Grumman versus Cirrus versus Diamond versus :dunno:.
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Did that once in my flying career:confused:......once was enough to never ever do it again, especially since left foot was higher up on the pedal than right. Caught some grass on port side and still dont know if the squealing was the tire skid or my buddy right seat thinking I'm about to trash his plane.....and now I know know piper didnt make the ledges on the bottom of the pedal to rest your heel on while landing.....:nono:

after gump check during undercarriage I find my self ending with "brake check, heels on floor"
 
MultiMediaWill said:
but flaps reduce stall speed right?
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They do yes. Like I said I really don't see any issue dropping the flaps in a bank. But I don't find myself in a need to.

Only exception is flying a Debonair or older Beech with a horrid flap system that requires you to hold a lever down, count, and then look out the window to verify the correct position. That's a lot of work to do in a turn.
 
Henning said:
:confused:You must be landing way too fast or always real heavy. I have flow the 337 (well, O-2) and I had no problem with landing short unless I was at gross, and even then 3000' with light braking no worries. What speed are you coming across the threshold at?
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A big factor in many twins is the idle RPM setting. Crank that up a couple hundred and it will seriously lengthen your ground roll without brakes. Add 400-500 and it might never stop on level ground without braking.
 
timwinters said:
I don't worry about elevation or what leg I'm on when deploying flaps.
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Obviously you do otherwise you would not be doing the following:
When flying a standard pattern, I chop the power abeam the numbers and put in one notch then trim for 70 mph.

When when I turn base I look at the runway and gauge how high I am. I decide to put in the second notch based on the sight picture.

Then when I turn final I look at the runway again and decide when to put in the third notch. It may be immediately, it may be later and, hell, I may have put it in before turning final if I was high on base.

The fourth notch is put in when the runway is assured (and if there's nottoo much crosswind).

I seldom consult the altimeter in the pattern after I chop the power abeam the numbers.
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Again, if you used some other keys other than position in the pattern, then you don't have to change your method for a non standard pattern. Or if the controller gives you a straight approach, do you say "unable, request downwind entry"?

And using altitude works for any approach, including an IFR where you can't see the runway.
 
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