What does the POH say about flap settings?

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Trey Kule
Posts: 250
Joined: Tue Aug 09, 2016 4:19 am

So, what do you think of the POH recommendations/advisors etc, as regards using landing flaps in non cross winds.


Chuck Ellsworth

Generally speaking I use flaps to get the performance I want at the time.


Generally speaking flaps lower stall speed and will give shorter landing for a given landing.


I generally use " landing flap setting when landing "


Regardless of the phucking wind.


If the wind speed and direction is beyond safe handling for a given runway I find another runway.


In other words if the wind is so bad a reduction of flaps may improve the handling of the airplane the small improvement is not enoug to mitigate the risk.
Trey Kule
Posts: 250
Joined: Tue Aug 09, 2016 4:19 am

That seems to be the consensus of those with experience. 
I have to wonder if the FTU's are teaching something different to new students, and more importantly, if they are, why they are.
Chuck Ellsworth

You and I are from a different generation, when we learned to fly the instructors were trained with the mindset of the pilots who learned to fly during the war years, military training was very flying oriented.


Today the training is paper oriented and tightly controlled by a bureaucracy that can't find their assholes with a set of moose antlers and a flashlight.


The instructors can not be blamed for something they don't know how to do, as in fly an airplane properly.


Just watch some of them land in a crosswind..it is horrifying.
David MacRay
Posts: 1259
Joined: Wed Jun 03, 2015 3:00 pm

[quote]Interesting, although its a x-wind situation and not just a stronger wind. Does the POH give minimum flap settings for different field lengths?[/quote]

Sort of, on the short field performance chart it lists 40 degrees of flap as a condition.

For normal landings it states "approaches can be made with power-on or power-off with any flap setting desired." And then further down, "Steep slips should be avoided with flap settings greater than 20 degrees due to a slight tendancy for the elevator to oscillate under certain combinations of airspeed, side slip angle, and center of gravity loadings."

Section 2 lists placards.
There is supposed to be a placard near the flap switch, "AVOID SLIPS WITH FLAPS EXTENDED"
JW Scud
Posts: 252
Joined: Sun Aug 14, 2016 12:44 am

I typically use lesser flap settings in stronger crosswinds on aircraft that have high drag flaps(such as a C172) while in more slippery aircraft with less effective flaps(such as a Mooney) I will use full flaps in stronger crosswinds.
Trey Kule
Posts: 250
Joined: Tue Aug 09, 2016 4:19 am

From what I understand here, the 172 POH does not specify that procedure .
So the question is "Why do you do it that way?"  What is your thinking on this?
Would be great to hear what the Mooney POH says about flap settings.


As to the comments of drag-etc..It is about control.  Does the aircraft actually control differently?
Maybe extra drag is a good thing in a wind. Allows you to come in with power putting more air over the tail, and maybe making the plane less suspect able to gusts.(I am not stating this is the case. I am just mentioning it so you can give your thoughts on similar control issues. My time on a 172 is...well.....  limited and a very long time ago.

While I question some of the posts, please understand I am not trying to be critical. Just trying to get to what seems to be a pilot choice, and  their thinking behind it.



As an aside.  One of the dangers I have witnessed over the years is pilots using perfect logic to come to the totally wrong conclusion.
And you can see from the posts here that some pilots choose to ignore what the POH advises and do things their own way. It has apparently worked out so far from them, so naturally we can assume it always will have a favourable and predictable outcome.


Which was the point of starting this thread...A group of very experienced pilots who could not really figure out why pilots were trying to land without flaps  because of the wind.  We thought there might be something in the POH's specifically regarding this, but it seems not really much.
JW Scud
Posts: 252
Joined: Sun Aug 14, 2016 12:44 am

Perhaps the so-called "very experienced pilots" are not as experienced as they claim to be. A large percentage of training aircraft are covered by the Piper Warrior and the Cessna 172. Both of their manuals along with the Grumman Cheetah say to use reduced flaps for landing in strong crosswinds. I suspect that is why many instructors are teaching what they are teaching.

The Mooney along with Diamonds which have relatively low drag flaps do not suggest doing reduced flap crosswind landings in their POH's.

I have flown all these aircraft and it seems to fit in with my previous post about high drag versus low drag flaps and crosswind landings. I have to admit that I wasn't even sure what the POH's would say when I looked them up but they seem to back up my logic(or it is just coincidence). I don't have a C-150 POH but think about it for a minute. Would you really suggest using 40 degrees of flap in a strong crosswind. Meanwhile, Mooney flaps do almost nothing for you anyways(or so it seems) so full flap is what I would be using.

And just because a manual has no suggestion about what flaps to use in a crosswind doesn't mean that common sense should not be used. Some of the older aircraft have extremely limited information about piloting the aircraft. I flew an old Cessna taildragger with "barn door" flaps that has a four page manual(known as an AFM) which is mostly just performance numbers. An "experienced pilot" should be able to use his experience in an aircraft like this to know that putting them all the way down is not a good idea in such a situation. That particular aircraft manual doesn't say whether I should do a three pointer or a wheelie in a good crosswind either but I have enough experience to know what I will do in such a situation.
Chuck Ellsworth




[quote]That particular aircraft manual doesn't say whether I should do a three pointer or a wheelie in a good crosswind either but I have enough experience to know what I will do in such a situation.[/quote]


Care to share it with us, like tell us what you do in that situation and why?


As to the Grumman Cheetah I had one in my school.


I never saw any problems using full flaps in cross winds.


[quote]


[font=verdana][size=0px]Perhaps the so-called "very experienced pilots" are not as experienced as they claim to be[/size][/font][/quote]




Really?


But you are more expert than us ?
JW Scud
Posts: 252
Joined: Sun Aug 14, 2016 12:44 am

[quote author=Chuck Ellsworth link=topic=5846.msg15392#msg15392 date=1489859689]
As to the Grumman Cheetah I had one in my school.
I never saw any problems using full flaps in cross winds.
[quote]

The original poster has specifically and clearly asked why instructors are teaching students to land with reduced flaps in strong crosswinds. I have just answered that it is likely because the POH’s of many of aircraft say to do so. Whether they are applying this to other aircraft where the POH does not recommend this technique, I cannot say.

From the 1977 Grumman Cheetah POH on page 4-21, “When landing in a strong crosswind, use the minimum flap setting required for the field length.”
It appears that you have been doing differently than what the POH says. Obviously it must have worked out OK for you and I am sure that it can be safely done but I suspect that there was a reason why the manufacturer made this statement along with similar from Cessna and Piper.


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