Dropping flaps while in a turn

RyanB

RyanB

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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
 
Doing it in the turn is fine. What's next teaching people to just not fly?:rolleyes2:
 
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.
 
I often put the next notch down on the base turn to end up with a more stable final and control speed easier.

But what the OP is saying I've heard before.
 
Yes, it absolutely affects aerodynamics, that's what they're for; and no, you do not have to wait until you're level but you have to KNOW your airplane and what the aerodynamic impacts are and how to handle them.
I fly at a controlled airport where they ask me to do things like "make best speed to the numbers" and I have CHOSEN to lower the flaps in the final turn but I made sure I was coordinated and prepared for the change.
 
It's nothing for an experienced pilot, but beginners may have difficulty managing two tasks in parallel. In particular I expect 1) turn getting ragged, nose-down and speeding, or nose-up and stalling, while the student grapples with flap switch, 2) getting distracted and forget to stop the extension and always going to 40 degrees.
 
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.
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Find another instructor.


Ryanb said:
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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No. Yet another myth being perpetuated by inept instructors. :nonod:
 
I believe the source of the "don't deploy flaps while turning" theory is that if you have a flap failure and differential deployment...i.e. only the high wing in the bank deploys, then you're already banked and have less of a chance to successfully counteract the roll tendency.

I've never heard of it happening so I don't worry about it. I deploy flaps when I need to deploy flaps, level, banked, inverted, whatever. ;)
 
Not all approaches are square.
 
This is something I was taught as a Student Pilot some 45 years ago, and the reasoning was that if there's a flap malfunction and they extend asymmetrically with the resulting roll-off in the direction of the turn at low altitude, it might result in a situation where there was insufficient altitude for recovery. If that possibility concerns you, then don't change flap position in a turn in the pattern. If not, just be aware of the possibility and be ready to deal with an asymmetric extension if that should happen (which it hasn't for me in some 8000 hour of light plane flying including a lot of flap position changes while in a turn in the pattern).
 
Very long and contentious thread on this already.

I do choose to generally deploy flaps with wings level out of habit, and think I can justify it, but have already done so in the other thread.
 
Flaps in a bank is fine.

Flying a very tight pattern I would do it often.
 
I do it once in awhile in my Bonanza. No problem at all. Typically I'm going from 10 degrees or so to full flap in the turn. I do it for short grass strips I frequent now and then. If you know your plane it's a non-issue.


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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.
 
The ONLY times you should avoid flaps are (1) electrical power failure or smoke in the cockpit, if flaps are electric, (2) a known problem with the flap switch/actuator/mechanicals, or (3) icing. The last one is important. If you're carrying ice, don't touch the flaps.

But flaps in a turn? Why not?
 
Theboys said:
Hardest habit to break is pulling flaps up on rollout to increase braking.
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...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).
 
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.
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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?
 
timwinters said:
I believe the source of the "don't deploy flaps while turning" theory is that if you have a flap failure and differential deployment...i.e. only the high wing in the bank deploys, then you're already banked and have less of a chance to successfully counteract the roll tendency.

I've never heard of it happening so I don't worry about it. I deploy flaps when I need to deploy flaps, level, banked, inverted, whatever. ;)
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This is the reasoning I've heard too. It's highly unlikely, maybe almost impossible, but I still don't want my last thought to be "Man, I just hit the one in a billion chance and there was no reason for it". I change flaps when straight and level.
 
The only way I see deploying in a turn being a really serious problem is in a split flap deployment malfunction.
 
I've dropped the first 10 degrees in a turn before. I would be comfortable even doing 20. But anything beyond that I wouldn't do. If you know how your plane flies in different configurations, and are capable of flying it that way, go for it.
 
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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Yep. I see a lot of pilots fiddling with the flaps, opening windows, changing transponders, putting charts away, etc on the roll out. It's a really bad practice.
 
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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Not really, it's a tool, just need to know when to use it and when not to.

I've used it on some super heavy crosswind landings, used it on a few other places too.

If you cross the threshold at vref, touch down and pull the flaps up, you're still touching down at the same speed as with the flaps, the difference in aerodynamic braking isn't going to be the same as coming in 0 flap from the ghetgo.
 
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. I don't understand why the simple act of being in a coordinated banked turn makes it harder to roll the airplane.

If you lose enough control to die from a split flap done from a 20-30 deg. banked turn, then you're probably gonna die if the flaps were dropped from level flight too.
 
I've always categorized this as an old wive's tale. If you were to have asymmetric flap deployment in a turn the turn would have a 50/50 chance of either making it better or worse, a risk I'm more than willing to take. The only other reason I've heard is that it changes handling and performance characteristics of the aircraft and could result in a loss of control. Personally, I think if the latter were true of any pilot, they should seriously reevaluate flying as a hobby and/or profession or get some serious remedial training. Besides, there's nothing more fun than chopping the power abeam the numbers, slowing below Vfe and dumping all your flaps, while pushing in full rudder and flying a heck of a short approach. :D
 
I was taught not to do it for the reasons stated. In the mooney I was taught to drop full flaps downwind, 70 mph. As a result I never had a go round and usually operated out of a 2100 foot runway. The mooney likes to float but if your set up correctly, on final it's a piece of cake. I landed it as I would a taildragger. Wonderful airplane.
 
Sounds more like a CFI thing than an aerodynamics thing. As someone stated, lowering the number of things going on simultaneously till you get more muscle memory.

The main thing on base to final is not worrying about the extra lift and drag flaps bring, but making sure you don't cross control, dip the nose and pull back on the stick entering a dead-mans spin close to the ground.
 
Jimmy cooper said:
I was taught not to do it for the reasons stated. In the mooney I was taught to drop full flaps downwind, 70 mph. As a result I never had a go round and usually operated out of a 2100 foot runway. The mooney likes to float but if your set up correctly, on final it's a piece of cake. I landed it as I would a taildragger. Wonderful airplane.
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What model mooney? I get to fly an old 1966 M20F occasionally and was taught if Im over the fence at 70 there is not too much difference between full flap and no flap regarding landing distance (I have even practiced this a few times, and Im not great yet but its about 1000-1300ft). The biggest difference I feel is a heavier yoke and almost clunky flair so I slip if needed and usually do no flap landings (but im not flying into 2100ft runways). One thing about that mooney I do have to admit, it is the one of the easiest (smoothest) planes I get to fly regarding landing. Almost lands itself, ,,:yesnod:Almost.

But Its the only Mooney I have had the opportunity to fly, so I wonder how they compare.:dunno:

Oh yeah, and to be cognisant of the original post. It depends on the plane, the pattern, and what I need to do. When I started flying I only deployed flaps on the level, but as my skills improved and what plane Im flying I will make a choice (ie, mechanical flap, electrical, hydraulic).
 
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Just don't do it while also raising the nose.
 
If you are going to do an asymmetric flap deployment in a turn, make sure the inward flap is deployed first.
 
ateamer said:
Why would asymmetric flaps be worse in a turn than in level flight?
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Because if left unnoticed, you could wind up inverted or worse.

That said - its not that big of a concern. I have had asymmetric flap deployment once. It felt like a bit of an annoying tug in the wrong direction.
 
ateamer said:
Why would asymmetric flaps be worse in a turn than in level flight?
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Less time to react before you are upside down, I'd imagine. If you're already in a 30-degree bank and the asymmetric deployment tosses you further into the a steep bank while simultaneously increasing the drag/decent, it might make recovery from that situation much more difficult than if wings were level, simply because you'd have a few more seconds to react before you are knife-edged.

The additional problem might be being able to identify the problem. If you're already in a bank and dropping flaps at the same time, what is causing the loss of control? Ailerons? Trim? Flaps? If you were trimmed, straigh-n-level, and then deployed the flaps when the upset occurred your natural logic should lead you straight to the flap deployment as the first probable cause, and thus, a quicker reaction/solution to the problem.

It's an extremely-low probability failure item, but why chance it?
 
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.
 
Jimmy cooper said:
I was taught not to do it for the reasons stated. In the mooney I was taught to drop full flaps downwind, 70 mph. .
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Entire downwind 70 with flaps?

I fly downwind 15" clean, which is 90-100kts. At the numbers, power to 11", gear down, takeoff flaps, start descent from TPA.
 
As long as you maintain airspeed and coordination, adding flaps in the turn is no big deal. There is more to do in the turn (re-trim, adjust power, counter the "balloon" effect, maintain coord.) but just fly the plane and all will be OK.
 
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
Click to expand...

It's all poppycock based on, "If you get asymmetrical flap deployment while already banked you might not recover!" It's all, bull****, and if your instructors taught you that, it's quite likely that 3/4rs of what you learned is BS and OWTs, sorry. Try to find someone with 30,000 hrs of GA flying for your next rating.

In an Air Tractor I'm rolling in and out flaps on every row turn.
 
MyassisDragon said:
What model mooney? I get to fly an old 1966 M20F occasionally and was taught if Im over the fence at 70 there is not too much difference between full flap and no flap regarding landing distance (I have even practiced this a few times, and Im not great yet but its about 1000-1300ft). The biggest difference I feel is a heavier yoke and almost clunky flair so I slip if needed and usually do no flap landings (but im not flying into 2100ft runways). One thing about that mooney I do have to admit, it is the one of the easiest (smoothest) planes I get to fly regarding landing. Almost lands itself, ,,:yesnod:Almost.

But Its the only Mooney I have had the opportunity to fly, so I wonder how they compare.:dunno:

Oh yeah, and to be cognisant of the original post. It depends on the plane, the pattern, and what I need to do. When I started flying I only deployed flaps on the level, but as my skills improved and what plane Im flying I will make a choice (ie, mechanical flap, electrical, hydraulic).
Click to expand...

I flew both a super 21 and a 201 . Many seemed to have trouble landing them hence the spoilers ( I never flew one with them) and many reports of go rounds due to floating , etc. on short fields ( 2100 feet) I had no problem as I said. It was all speed management as is the case in any aircraft. I agree that as I gained over 100 hours in the latter I simply applied full flaps on final , especially on longer runways. Some of this was on a grass strip also. I think a lot of tail wheel time helped me a lot. I also liked the bar gear. Very positive and easy to use once you got the hang of it.
 
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