Flaps in a turn

[boofhead]

I told a student undergoing a Stage check in a C172 that he should put his flap out to 20 when turning base and to the landing setting when turning final. He said his instructor had told him to never select flap in a turn.
I can see a tiny reason for this but the alternative is that the pilot waits possibly until the approach has become unstable, before putting the flap down.
I mean, a C172?? And a private student?
The only reason for not putting the flap down in a turn is if the POH specifically says that, in my opinion.

[bbrunton]

I agree with you but......


Something to consider.....


If a flap asymetry occurs while the flaps are moving, you might find yourself rolling in the direction of increasing bank near to the ground.

If the aircraft has flap asymetrical protection, then it is probably not going to be a problem because a soon a slight asymetry occurs the flaps will stop moving and there will be little chance of a loss of control near to the ground.

A far as I know, none of the small Cessnas have any type of flap asymetry protection and I have never heard of any problems with them.


Bill

[Unhinged]

I always like to start early with the habits that I want students to retain, and one of them is: Don't do anything else in a turn if you can avoid it.

It isn't a question of what the aircraft will stand, but a lot of my students go on to Instrument Ratings, and the pressure in imc can be substantial especially when handflying on single-pilot ops, so in a turn you just turn, that's all. Most aeroplanes are unstable in roll beyond about 5 degrees, so once you're past that, as in a normal turn, it's time to focus on the main game. If it happens to be a climbing or descending turn, then it's even more important to just do the basics first, and then deal with flaps/radio/gear/etc once the turning part is completed.

Of course, we're on opposite sides of the world, and I'm betting it's a very different training environment so your mileage may vary, but that's why I teach it here.

[Big Pistons Forever]

I have a big problem with "absolute " statements generated by instructors when it comes to good flying practices. Many are directives that seem to be mindlessly passed on within flight schools with little or no critical thought as to their theortical and practical justification. The "never put flaps down in a turn" stikes me as one of these "flight schoolism". As a general practice I discourage putting flaps down in a turn for a couple of reasons.

1) It is an admission that poor descent planning has occured because the pilot should hae managed the landing approach/circuit better

2) Low time pilots will generally do a poor job of flight path assesment if flaps are deployed in a turn as too many things are changing at the same time

3) While the chance of assymetric flap deployment is very very low it is not zero therefore all other things being equal it is better to deploy the flaps in level flight

However At the late stage of PPL training, and any stage of training thereafter I expect the student to make the airplane go where it needs to go. So for example if the tower requires an early and unexpected downwind to base turn rather than wait to finish the turn before putting flaps down and winding up very high, turning while deploying flaps can expidite reestablishing the correct profile, and therefore is what I would expect the student to do notwithstanding the points in 1 through 3 above.

[mad_jock]

Myself I don't have a problem with it as long as its not effecting the flight profile.

I wouldn't teach it, but if someone did it I wouldn't mention it either unless it led to some other cock up.

As BPF says you are expect to fly the aircraft safely within your limits, using the tools avialable. If one of your limits is you don't have the capacity to deploy flaps and to maintain the correct attitude while in the turn so be it don't do it. If you can I don't see the problem.

A far greater crime in my book is to select a flap setting and take your hand off the control before it has run and stopped. Not much of an issue in a piper I grant you, but the number of cock ups I have seen in flap selection with electrically deployed flaps have made me quite anal about this issue. It also has the advantage as well that if you do get any problems with assymetric flap you can get rid of them quickly instead of your instintive two hand grab to the yoke to control the roll.

[DeltaT]

For the inexperienced learner pilot, I wouldn't be so much worried about asymetric flap problems as I would about the tendancy for high wing aircraft to pitch nose up when flaps are established (lowering airspeed for the unweary), something you do not want in a turn with the stall speed slightly increased as well. Most learner pilots are having enough problems with their scan and knowing where the airfield is without all that happening.

[Ryan5252]

For the record, from very early in my training I always roll into base leg while deploying two stages of flaps. It is fairly instintive for me at this stage to come down from circut height to be nicely established on final; carb heat RPM to 1700, Flaps and forward pressure to maintain a decent airspeed.
That said, the approach on the other end of the runway 'seems' longer and I generally throw down flaps on base and the final stage of flaps after clearing a hill on the final approach path. (Whereas three stages are not generally required on the other end of the runway). I suppose as well as considerations toward the aircraft flown and the pilot flying it, consideration should also be made to the requirements of the approach pattern and local features such as terrain or built up areas. I would be confident that I can make a smooth descending turn in a clean configuration, with flaps or simultaneously deploying flaps and personally, I think that is crucial.

Ryan

[Lou Scannon]

This idea that flaps shouldn't be lowered in a turn goes back to the Wellington Bomber in WW11. Asymmetric flap tended to cause a roll that was difficult to control. The idea was still around in the 50's.

Small aircraft may be different but I can assure you that all the big stuff lower flap when needed irrespective of bank angle.

[boofhead]

The PA31 had a problem with asy flaps and there was a good reason to not move them in a turn. I have not flown any other airplane that might have a similar problem.
If the flap was to extend asymmetrically, it can be easily controlled, I would imagine, or else the manufacturer or CAA would state otherwise. What makes a flight instructor think he/she knows more about the airplane than they do? How many of us have had such a problem, and why is it more difficult to handle in a turn?
If anything does not work as expected when a control is moved, reverse the selection!
I have had an aileron failure in a turn that was more difficult than a flap failure, and being in the turn made me more aware of it. I would suspect that if a flap failed in straight flight the airplane would be in a turn before the pilots knew they had a problem, whereas if it happened in a turn, the pilots would be instantly aware and taking action to prevent excessive roll.
A late selection of flap will definitely give a lot of students problem with glidepath and speed control, and will definitely reduce the safety margins.
The risks associated with a late selection of flap (or an early selection if it is appropriate) are greater than the risks of a roll problem following flap failure in most, if not all, small airplanes.
Instructors should teach what is in the POH, and not make up problems. A verbal warning of the possibility of flap asymmetry and what to do about it should cover this area?
There is plenty of room for individuality without being radical.

[Charlie Foxtrot India]

My students learn quickly that "my last instructor said I should never/always..." is not a valid reason for doing anything unless it can be backed up by a valid reference eg POH, regs, or a very good aerodynamic argument.

The "not to use flaps in a turn" is something that comes up quite often. I am yet to be convinced.

[FlyingOfficerKite]

I was always taught (from PPL, through instructing to airline flying) that selection of flap in a turn is not to be recommended because it distracts the pilot/student from the primary exercise of controlling the aircraft.

The danger being, apart from any considerations of asymmetric flap, that the wrong flap setting might be selected or general lookout/instrument flying degraded by trying to do 'two things at once'.

I have never been taught to select flap in a turn and do not know where (in books, POH or whatever) it has ever been recommended or suggested?

KR

FOK

[eocvictim]

As an instructor I would never correct someone (who wasn't my own student) who selected flap during the turn. However in both PA28 and C172 it was painfully obvious that even "experienced" PPL's seem to have less authority over the aircraft while doing so.

I refused to send a student solo because he had no height control while introducing flaps in a PA28 and suffered Coriolis illusion bending down to grap the lever. I spent the next 30 mins shifting his flap selection to after being established on base and final and sent him solo the next flight.

As for myself, in 4-6 seat piston singles, whenever. In a PA31 and BE55 I've always waited until established on each stage. In a AC50/68 whenever I feel like it, honestly has very little effect on how the aircraft flies. In bigger turbine stuff usually prior to the turn due to the large amounts of trim required.

Should I dare to throw dropping gear into the mix? Mechanical VS Hydraulic/freefall extension during a turn. :}

[DeltaT]

Why are you all so focused on asymetric flap for crying out loud?!
Air speed reducing and stall speed increased presents more danger:ugh:
And yes we are talking while a pilot is learning kinda pre ppl level not at your advanced cpl and beyond level!:rolleyes:

[dynamite dean]

I had 14 different flying instructors two countries (UK as well) 4 years to finish off my PPL (long story). Some said use Carb heat on Downwind, on final , not on final, Flaps on base, one stage on downwind and so it went on bla bla...everyone had an opinion almost to the point that making the point was lost in making of the point! And it never stops further up the ladder. Someone will always have the worse case scenario as well. Just be practicle and logical in your decision making. I use to teach 1700rpm flap 20 2/1/2 turns on the trim wheel on base wings level .There will be on occasion you may need to deploy flap in a turn or not for whatever the millions of what 'ifs' Chill out enjoy your circuit training take your time roll wings level select your flap for what you gain by waiting 10 secs - Oh look and now Im at it giving my opinion!:oh:;):O

[belowradar]

I told a student undergoing a Stage check in a C172 that he should put his flap out to 20 when turning base and to the landing setting when turning final

Understand that you are teaching how you would like to see aircraft properly configured but ....I would say "FLAPS AS REQUIRED" e.g. no hard or fast rules and for full flap I would only expect to see that setting selected when we can definitely make the runway without dragging in on high power. Strong wind straight down the runway then maybe no need for full flap until the numbers, strong crosswind then no need for full flaps either.

Not bothered about selecting flaps in turn and generally expect to see flaps deployed base and final with aircraft stable and configured for landing by approx 300ft agl.

[eocvictim]

Why are you all so focused on asymetric flap for crying out loud?!
Air speed reducing and stall speed increased presents more danger:ugh:
And yes we are talking while a pilot is learning kinda pre ppl level not at your advanced cpl and beyond level!:rolleyes:

Because during a turn there is a lot of focus on attitude and spatial orientation. An asymmetric flap condition can come on quickly if not picked up (if your focus is on the turn perhaps?) and can result in uncontrollable flight.

Why is airspeed reducing? The airspeed should be constant throughout the turn.

Oh I didn't realise instructing stopped at PPL stage. :rolleyes:

[sapperkenno]

...that you initially teach only to use the flaps when wings level, primarily because of the pitch change, which for the inexperienced student, might not be picked up on, and airspeed could drop.
Much easier to get used to the "balloon effect" of lowering the flaps, and applying slight forward pressure, re-trimming etc when flying in a nice straight line with the wings level. If you have to think about all that WHILE turning, it's just extra crap that you can do without.
Also, to a lesser extent... the assymetric flap scenario... easier to see if wings level... and you're not already banked over at 20-30 degrees if they do deploy unevenly and roll you further over.

Obviously with time, practice and experience it's not really an issue, and probably why most of us here have forgotten about something that seems so natural (and possibly a bit basic) to us these days. :ok:

[FlyingOfficerKite]

sapperkenno

Yes, I agree.

It was quite simple when I was training, there was one 'approved' method of teaching and I never was taught any different on fundamental matters such as this - my training reflected the syllabus written in the textbooks.

Okay, there may be minor variations on a theme, but not when it came to issues such as selecting flap in a turn, or moving the heading bug in a turn or in fact doing anything in a turn other than flying the aeroplane (lookout when VMC and instrument flying when IMC).

Carb heat is quite simple too - in the UK at least - during PPL training in the circuit. Exercise when downwind (amongst the pre-landing checks), select 'hot' on base (low RPM), select 'cold' on finals to ensure full power in the event of a go-around. Now you can debate the whys and wherefors until the cows come home, but if you stick to that simple procedure you can't go far wrong. Obviously there are other occasions when carb heat may be used as required. Years ago having suffered carb ice when I didn't expect it (often first flight of the day, on the ground after the dew had lifted) it is something that you are aware of at all times and act accordingly WITH EXPERIENCE. For the student, best stick to one method of teaching and not confuse the issue by bringing personal ideas and experiences - stick to the way you were taught to instruct.

There seems so much debate on PPRuNe about matters that should be 'nailed'.

Why is there so much variation in flying training - I can't believe flying instructor courses vary so much?

Over the years I have noticed this variance and whilst I'm happy to accept 'variations' when instructing with other peoples' students or with PPLs, I'm not willing to accept 'bad practice'.

KR

FOK

[boofhead]

I used to do the same with the carb heat, but a closer look at the Cessna POH shows the carb heat should be pulled when power is reduced for landing and not put to cold until just prior to shut down (or in some cases after landing). If a go around is needed, the carb heat is put to cold at that time.

Dusty surfaces need to have the carb heat in the filter position of course.

In Alaska in the winter you will lose your engine in a C150 if you don't follow this procedure. You should set full power for takeoff with the carb heat HOT, and only go to COLD when the engine is up to speed and running smoothly. With the carb heat in COLD you often will not even be able to get the engine to accelerate, and it will die when the throttle is opened.
If you have the carb heat cold the engine will die when you close the throttle on final for the landing and you cannot guarantee that it will start again to taxy off the runway. The Cessna 172 does much better, but the procedure seems good for both types.

The DHC2 on the other hand seems quite happy if the carb heat is set to COLD for takeoff and set to COLD again on short final.

Point is that the POH should tell you what to do and an instructor should be careful when teaching contrary to that. This includes setting flap in a turn, which so far as I have read is not restricted in the POH.

[FlyingOfficerKite]

boofhead

Yes, once again I agree.

The flaps in a turn thing is more to do with good airmanship than it is to do with the POH for a particular type (can't imagine why it would be mentioned?).

The carb heat issue is more a question of standardisation - but naturally with the proviso that the POH should be followed.

I teach configuration changes when straight and (maybe) level. In practice (when not instructing) I select flap when straight or in a turn if necessary because I know what to expect and it often assists with positioning at larger airports when doing a 'dirty dive' ahead of commercial traffic.

Selecting flap in a turn during a visual approach in a B737 can just nicely bleed the speed off between flap 1 and flap 5 so that works too.

But to complicate matters for the student at a relatively early stage in their training is another issue and better, I feel, it stick with tried and tested methods and not try to be too clever and risk confusing the issue.

No harm is done by using carb heat in this manner (in the UK) and better the student is aware of its use than not consider it when flying.

All my instructors from ab initio to CPL have taught the use of carb heat on the C150/152 and C172 in exactly the same way. Whether they were right or wrong I have never had an in-flight carb icing problem whether in the circuit or in the cruise.

It must be said that I was told that selecting carb heat on the ground or selecting flap in the turn were 'bad habits' and not to be used.

As for asymmetric flaps - that would be the least of my concerns in light singles.

Interesting how the World views these issues away from the particular training environment in North West England (particularly in the 80s and 90s).

It never fails to amaze me how often in aviation the wheel is re-invented. One airline was still reviewing SOPs on the HS748 forty years after it first came into service and had been operated for years by BA and Dan Air.

These debates continue un-abated and it keeps the conversation flowing whilst downing the obligatory pint when the flying is over!

Maybe all that is required is a 'non-standard' call and all will be okay in these situations?! (but don't tell the students, they have enough to contend with as it is!!!)

KR

FOK

[BEagle]

Flap asymmetry in the turn is virtually unheard of. Yes, there have been accidents caused by flap asymmetry, but the risk of that happening specifically in a turn is miniscule.

The only reason I would suggest that the practice should be avoided is that it is more difficult for a student pilot to select the correct attitude to maintain the desired IAS if flap is selected when in a turn. But a more expereinced pilot should be able to cope.

Of course, back in Hunter days, the practice of parking the throttle at full power and using 23 flap to out-turn the opposition during 'Harry Doggers' was an essential skill - but that's an altogether different story...:cool:

[OneIn60rule]

IT was not very long ago that I heard of asymmetric flap. This was in reference to a PA-28.

Ever since that mention I keep that in mind and mention never to use flaps whilst turning. Only straight-level or descending etc.

IF there is even a 0.01% chance of it happening. What's wrong with abiding by that logic?


I could look at this end, student selects one stage of flap whilst turning, aircraft settles but he is unaware that only one side has gone down, he then selects one more stage. Now 2 stages of flap on up going wing.


What will then occur and would he not have noticed it more if he had been level and straight etc?

And will they all react the same way? *Probably not*

I teach the same method on all aircraft irrespective of design and can't find a problem in doing so.

[FlyingOfficerKite]

aircraft settles but he is unaware that only one side has gone down???

This from Google books Airplane Flying Handbook - Google Books (http://books.google.co.uk/books?id=V3SZXFWuCIgC&pg=SA16-PA8&lpg=SA16-PA8&dq=effects+of+flap+asymmetry+and+light+aircraft&source=bl&ots=HkPNLmfEpy&sig=9u9lvEzFsdDljH8Jnli5WPdtIuA&hl=en&ei=TDevS7TAGIiz4QbLi527Dw&sa=X&oi=book_result&ct=result&resnum=3&ved=0CBAQ6AEwAg#v=onepage&q=&f=false)

and from the AAIB http://www.aaib.gov.uk/cms_resources.cfm?file=/dft_avsafety_pdf_502394.pdf

I think the incident with the C172 (1. 1985) MIGHT refer to a story I was told by an instructor who later became a CAA flight ops inspector (?). If that is the case the report in the article doesn't do justice to the trauma experienced after the asymmetric flap and the efforts that had to be made in order to maintain control. The comment in the report On selection of 0° flap from 10°, a loud bang was heard and the aircraft rolled right. The instructor had to apply full left aileron and rudder and close the throttle
to arrest the roll. (my emphasis) further clarifies that an asymmetric flap condition even at 'first stage' can be violent and only just controllable (as it was in this case).

This is an event that would NOT go unnoticed!

I teach the same method on all aircraft irrespective of design and can't find a problem in doing so

IMHO revise your 'patter' in this respect.

KR

FOK

[Flyingmac]

Cases of engine failure outnumber flap failure by tens of thousands to one. Should we therefore avoid reliance on an engine?
I use a constant aspect approach which means that from downwind to very short final I am in a turn. Flaps down as and when required. I'd no idea I was dicing with death all these years. I'm shaking now.

[B2N2]

The POH or AFM doesn't teach you how to fly, it simply has "guidelines" and the Limitation Section.
A C172 POH doesn't state to not fly the aircraft upside down, it only states a max. positive and max. negative g-loading
A PA-28 POH does not state not to land in a 40 kt crosswind, it only states a maximum demonstrated xw component.
So the POH does not state not to put the flaps down in a turn...point being?
That it is good airman ship and proper planning to do so?
The fact that it is not mentioned does not make the opposite correct.

Lots of reasons have already been mentioned as to why this is not a good idea for primary training:

altitude control
speed control
spatial orientation
division of attention


40 hrs of training is not enough to learn all the in's and out's of airplane control.
Assuming so is like comparing a fresh drivers license holder to Colin McRae, we shouldn't encourage them to use the hand brake in a turn either even though it is a very effective technique.

Arguments like: this is what I can do ( with all my experience) so therefore I teach it (or allow it) are dangerous.
This is going to come across as arrogant, but that hasn't stopped any of the previous posters either, I can use flaps in a turn down low to the ground and even bring them back up just prior to touchdown. But that doesn't mean that I teach it.
I was a very dangerous flight instructor for the first year or so, teaching students what I can do. Luckily I learned before I got anybody killed.
Teaching what you know and what you can do is not what flight instruction is about.
Teaching the part of it which is appropriate to the certificate or rating is.
So to summarize:

don't put flaps down in a turn
don't bring flaps up prior to touchdown
don't go down the entire runway on one wheel
don't do touch and go's on a short runway
don't exceed your crosswind limitations, forget about the POH
don't do gear up low approaches
don't scud run
don't penetrate weather
don't mess with thunderstorms
don't fly over water with visibility less then 20 miles
don't fly VFR at night without an instrument rating


because as a Private Pilot you do not have the skills and knowledge to do so with any degree of safety.

[Tralika]

Why are you giving instruction during a Stage Check? The purpose of a Stage Check is to determine if a student meets the standards for that phase of his/her training. If the student could not fly a stabilized approach I guess I could understand making some suggestions but shouldn't the subject of new techniques be taken up the the student's primary instructor? When students are not performing well on a Stage Check I ask them what went wrong. Most of the time they know and after they explain it to me they are able to correct it on a second try. If they don't know what they are doing wrong it's time to end the flight and go have a talk with their instructor. Take a look at the lesson plan for the Stage Checks in your syllabus, I bet you will not find the word "Introduce".