lift increase whan applying flaps

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FLYING TIGER
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lift increase whan applying flaps

Post by FLYING TIGER »

Hello guys,
I must repait a question I already asked (± jan. 2016)but got no real answer/sollution to. I'm talking about the 2 Cessna's -172 & 182. When I'm on approach,flying level, at the right speed and power (believe me) and I apply the first stage of flaps the nose realy rockets to the sky due to an enormous increase in lift. I have to put the yoke more that an inch foreward to try to compensate this movement, and then trim a whole lot nose down because ohterwise when I stop pushing the yoke foreward it shoots up again. So a nice steady decent is absolutely impossible until I get the controls back in order. The 2 nd stage also overdone (but less that with the first stage). I’m not the only one who say so. I let others, with much more flying experience than me fly on my system, and the all say the same thing. This is not a normal behaviour. I watched several videos on YouTube with approaches and landings in both airplanes (with the panel in vieuw so I could check the instruments and try to do the same) and not one of them have the same problem. I know it is normal that you get a bit of a lift when applying flaps, but this is way over the top. It’s a pity I can’t make a film/video of it so I could prove my point. I don’t have this problem with other planes (also not in your Cherokee 180). It takes all the fun out flying and I’m am realy fed up with it.
I tried a few changes in the config files but to no advance, and it is no good sollution anyway. Is there a possiblity to find there? All my sliders are in the right position. Full sensitivity & no dead zones (except a little dead zone for the elevator).

Also flaring is hard to get right, but I’m not the only one here (see forum). The slightest pull on the yoke starts ballooning the plane, but I’m getting there one step by step.
I fly P3D version 3.3 with the Cessna yoke/trim/pedals from Saitek.

Hope to get some help from the more experieced simmers (I guess the usuals suspects: Nick / Lewis / Scott etc. ) :D :wink:

Thanks in advance & kind regards,
Eddy

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Nick - A2A
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Re: lift increase whan applying flaps

Post by Nick - A2A »

Hello Eddy - plenty of simming experience here, but none whatsoever in the real thing I'm afraid, unlike many here.

However, I reckon part of the reason your pilot friends are finding the nose-up pitch change when the first stage of flaps is extended 'surprising' is because there are no control forces in the sim.

Same goes for those videos. They just can't show control forces: i.e. the pilot counteracting the yoke pushing against his or her hands. This is something we just don't have in FSX/P3D (unless we own some pretty specialised hardware) and as a result I suspect it's more difficult in the sim to counter the pitch response of the aircraft during a configuration change.

I'm interested in the thoughts of the real pilots on this one too, but I don't really doubt the magnitude of the pitch change when extending flaps: remember, those are pretty big flaps on the Skyhawk! :)

Nick

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AKar
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Re: lift increase whan applying flaps

Post by AKar »

While it is a little beside the point, it perhaps could be pointed that the added lift from the flaps is not in a direct causal relationship to any pitch effect (some airplanes actually pitch down while the flaps still add some lift).

No time on real late model 172, so no real comment on the topic, but what could be mentioned is that A2A planes apparently simulate the tactile feel of the airplanes rather strongly, requiring one to put quite a bit more "effort" on the PC controllers than in most other simulations.

-Esa

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Oracle427
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Re: lift increase whan applying flaps

Post by Oracle427 »

So I just happened to be flying a 182Q yesterday and doing all sorts of maneuvers including stalls, steep turns, lazy 8's and slow flight. I got a lot of time observing the amount of pitch up and altitude gained with just 10 degrees of flaps. I wish I had taken my GoPro along.

When I added 10 degrees of flaps at idle power and 110KIAS I intentionally did not touch the yoke or trim. The nose pitched up probably by 5 degrees and I gained about 200 feet before the aircraft slowed to around 85KIAS.

What figures are you getting in the sim?

I'll see if I can make specific notes of actual performance next time. Wish I had seen this post earlier.

I will note that I normally have to apply firm pressure to keep the nose level and maintain altitude when I initially introduce flaps. Only at the point when I go from 20 to 30 degrees of flaps is when I notice a significant increase in drag vs lift and the nose will pitch down as the airspeed rapidly decreases.
Last edited by Oracle427 on 12 Oct 2016, 15:11, edited 1 time in total.
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DHenriques_
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Re: lift increase whan applying flaps

Post by DHenriques_ »

FLYING TIGER wrote:Hello guys,
I must repait a question I already asked (± jan. 2016)but got no real answer/sollution to. I'm talking about the 2 Cessna's -172 & 182. When I'm on approach,flying level, at the right speed and power (believe me) and I apply the first stage of flaps the nose realy rockets to the sky due to an enormous increase in lift. I have to put the yoke more that an inch foreward to try to compensate this movement, and then trim a whole lot nose down because ohterwise when I stop pushing the yoke foreward it shoots up again. So a nice steady decent is absolutely impossible until I get the controls back in order. The 2 nd stage also overdone (but less that with the first stage). I’m not the only one who say so. I let others, with much more flying experience than me fly on my system, and the all say the same thing. This is not a normal behaviour. I watched several videos on YouTube with approaches and landings in both airplanes (with the panel in vieuw so I could check the instruments and try to do the same) and not one of them have the same problem. I know it is normal that you get a bit of a lift when applying flaps, but this is way over the top. It’s a pity I can’t make a film/video of it so I could prove my point. I don’t have this problem with other planes (also not in your Cherokee 180). It takes all the fun out flying and I’m am realy fed up with it.
I tried a few changes in the config files but to no advance, and it is no good sollution anyway. Is there a possiblity to find there? All my sliders are in the right position. Full sensitivity & no dead zones (except a little dead zone for the elevator).

Also flaring is hard to get right, but I’m not the only one here (see forum). The slightest pull on the yoke starts ballooning the plane, but I’m getting there one step by step.
I fly P3D version 3.3 with the Cessna yoke/trim/pedals from Saitek.

Hope to get some help from the more experieced simmers (I guess the usuals suspects: Nick / Lewis / Scott etc. ) :D :wink:

Thanks in advance & kind regards,
Eddy
Generally speaking a high wing airplane will exhibit a pitch up with flap deployment due to center of gravity location especially with the first two notches of flaps where lift is dominant. The reverse is mostly true for low wing airplanes that will pitch a bit nose down. There are exceptions of course and airspeed and flap area and control surface area are factors as well.
Dudley Henriques

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Nick - A2A
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Re: lift increase whan applying flaps

Post by Nick - A2A »

Oracle427 wrote:When I added 10 degrees of flaps at idle power and 110KIAS I intentionally did not touch the yoke or trim. The nose pitched up probably by 5 degrees and I gained about 200 feet before the aircraft allowed to around 85KIAS.
That's definitely a good bit less dramatic than the effect in the A2A version Oracle. In the quick test I just did, adding the first 10° of flap at 110 KIAS caused about 15° of pitch up with the airspeed dropping below 60 KIAS before the nose dropped again. Perhaps the OP has a point?
Oracle427 wrote:I got a lot of tinge observing the amount of pouch up and slide gained [...]
Lovin' the, er, aviation jargon by the way! Are you dictating to Siri or something? :wink: :mrgreen:

Cheers,
Nick

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Oracle427
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Re: lift increase whan applying flaps

Post by Oracle427 »

Silly Android autocorrect madness!! :) Grrrrrr

What that should have said was, "I got a lot of time observing the amount of pitch up and altitude gained."

That is quite a bit more pronounced than I would expect. I was in a Q model and have never flown a T.
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bobsk8
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Re: lift increase whan applying flaps

Post by bobsk8 »

Slow the aircraft down first, and then apply flaps and you will see less pitch up.
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Oracle427
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Re: lift increase whan applying flaps

Post by Oracle427 »

Bobsk8,

The question here is how accurate the behavior is, not how to compensate for it. I don't have the A2A 182 *gasp* so I can't compare it to my experience. I have so much fun with the current fleet I have right now and it's so hard to pick one to fly as it is without neglecting the rest.
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FLYING TIGER
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Re: lift increase whan applying flaps

Post by FLYING TIGER »

Hello guys, (I’m going to answer in general to all your replies)
Wow, what a response. A couple of thoughts: when I’m talking about pilots with much more expertise as me (NICK), I’m talking about guys who all fly the sim, although some of them have their PPL.
I will test fort he figures again (oracle 427) but I thought they were in that post from the beginning of the year somewhere, but as I said I will both test the 172 and the 182. Results ASAP. I did know that the first stage of flaps create more lift than drag and the other way around with the latest stages of flaps.
You are right (DHenriquesA2A) the problem doesn’t occur with the A2A Cherokee (= low wing airplane). I have not thought about it that te CG changes with the use of flaps, but it’s logical.
(Nick) what you saw in your quick test is pretty much what I experience. What is an OP Nick??  Are you refering to me and what does it mean ??? Hey, I’m not English spoken, never had any lessons so I’m not familiar with this expresion so don't shoot me for asking silly questions :mrgreen: . My native tongue is Dutch. Flemisch to be more presice, I’m from Belgium but live in Holland now.
I tried that (Bobsk 8) but to no avail. Tried all kinds of things but no satisfactory result so far.

I am going to cantact somebody who makes very good video’s on simming. Gonna ask him what program he uses and I will try te post a video in the near future. A picture tells a thousant stories so they say. Hope it does.

Thanks again fellow for the help so far. I appreciate it very much :!: :!: :!:
Greetz, Eddy

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Nick - A2A
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Re: lift increase whan applying flaps

Post by Nick - A2A »

Yeah, videos are always good when discussing this kind of behaviour Eddy. If you have a fairly recent NVIDIA card, their free Shadowplay software is pretty good, it's what I've used for recording a few short vids like this one. (Long ones just take too long to upload!)
FLYING TIGER wrote:What is an OP Nick??  Are you refering to me and what does it mean ???
OP = "Original Poster", so yes I was referring to you. :) Sorry, I generally try to avoid too much internet jargon but occasionally laziness gets the better of me! :mrgreen:

In terms of counteracting that nose up pitch change, it can of course be done but it takes perfect timing with the control input. Easier said than done, and I've found that when flying on instruments, it's even trickier. This is perhaps one reason why I found that getting the 182 configured nice and early when flying an instrument approach (i.e before intercepting the glideslope) was quite helpful in terms of being able to fly it more accurately.

Actually, I do recall watching one real world video which also seems to support the idea that the pitch up on the first stage of flap selection in the A2A 182 is perhaps a little exaggerated. It shows a very brisk approach in a 182T, controlled by the autopilot until around 500' AGL. 10° of flap are extended at about 3:50 into the video at an airspeed of ~130 KIAS which is pretty close to the VFE of 140 KIAS. The autopilot copes fine with the pitch change, but I don't think this would be the case in the A2A version.

Interesting topic anyway! I usually find it's quite educational to discuss the finer point of the flight model in this way, whatever the outcome.

Thanks,
Nick

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bobsk8
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Re: lift increase whan applying flaps

Post by bobsk8 »

Good article on use of flaps, read the section on pitching moments.
http://www.pilotfriend.com/training/fli ... _flaps.htm
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FLYING TIGER
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Re: lift increase whan applying flaps

Post by FLYING TIGER »

Hi Nick/Bobsk8,

I have a NVIDIA GeForce GTX 970 so I'm goin to check out shadowplay. Do I have to convert the video format or is it usable the way it is recorderd? I check it out and we'll see how it goes.
Speaking of a perfect landing in your vid Nick! But very uselful to see it a couple times more and try to learn from it. Thanks man.

Quite some article on flaps Bobsk8, haven't read it yet but I'm surely gonna do it. Also thanks man.

OK, I'll keep you posted.

greetz,
the one and only OP :D

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Nick - A2A
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Re: lift increase whan applying flaps

Post by Nick - A2A »

FLYING TIGER wrote:I have a NVIDIA GeForce GTX 970 so I'm goin to check out shadowplay. Do I have to convert the video format or is it usable the way it is recorderd?
No conversion necessary, though you may have to fiddle with the settings for recording resolution to get acceptable file sizes for your clips. I took me a while to figure out the whole interface and I think they've changed it since then. :roll:
FLYING TIGER wrote:Speaking of a perfect landing in your vid Nick!
Thanks Eddy, but some way off perfect I'm afraid. The idea was to have the stall horn blaring just a few moments before the mains softly touched the pavement. Still, it shows that ballooning (as mentioned in your opening post) needn't be too much of a problem, once you get a bit used to the control inputs needed and provided your airspeed is sensible. Actually, that's what I really like about landing the A2A planes: even once I think I've got the hang of it, nailing that really 'perfect' landing is still suitably elusive. :mrgreen:

Nick

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FLYING TIGER
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Re: lift increase whan applying flaps

Post by FLYING TIGER »

Hey Nick,
I installed the GeForce Experience package and configured Shadowplay, BUT.....I was aible to record a flight, I thought ! :? I use 3 monitors, the vieuw from the cockpit on the middle one (the 2 others for navigation and other stuff) but when I played the video it was the right monitor that was recorded, NOT the one where it's all happening. :twisted: I can't find any instruction on how to change the monitor recorded so far. No manual to be found. I created an account on the NVIDIA forum and posted a cry for help there. No luck so far (it's only a couple of hours ago). If someone of you guy's know how to do this (altough it's not A2A related) please let me know.

Not touching down when the stall horn sounds is only a minor detail and I wished mine were always that good. But I'm glad to say my landings are slowly getting better and better. Practice makes perfect! Just have a bit of trouble now just after the start of the flare, by drifting off to the right (most of the time / no wind). I loose site of the centerline when the nose rises and my vieuw is blocked and although I apply left rudder it still occurs. Need more practice as mentioned before.

So, until some reply from anybody thanks again for the good job.
Regards,
Eddy

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