Full flap/specialty landings - 172

[PilotDAR]

Excellent post CS.

Were I to have crafted those wise words, I would have added that flaps are installed to assist the pilot in reducing the speed when that is appropriate. Speed should be reduced as much as possible for the conditions, prior to landing. So the more flaps the better. Personally, I have NEVER landed had a problem controlling a 172 in a cross wind, with full flaps extended. I always use full flaps, but I realize that others fly differently. In my opinion, every "normal" landing, to which CS and others refer, should be at the greatest flap extension possible - that's normal.

For any GA tricycle aircraft, the nosewheel should be held off to the greatest extent possible, to prevent wear and possible damage. Therefore every "normal" landing should include nose light pitch control of the aircraft when touching down, and throughout the landing roll, until the elevator is no longer effective. That's normal.

So if students become very competent at these "normal" landings, that competence will form the basis for skill development in short and soft field landings, which are really just slight variations on the normal landings CS and I just described. All you can do to make a soft field landing out of a normal landing it to keep as much weight off the wheels as long as possible = nose light. All you can do to make a short field landing out of a normal landing is to Get it down and stopped in as short a space as possible = full flaps, nose light and add brakes.

CS is right, teach "normal" landings correctly, so students can do them well, and the rest will drop easily into place based upon that foundation of skill.

[Colonel Sanders]

I am sure that many people will think I am a bad person
because I like to focus on building solid, fundamental
skills wrt maintaining precise glidepath, runway alignment
and airspeed.

You might conclude that I'm a "3,000 foot paved runway" guy.

Heh heh.

Let's say we're in a 172, or some other similar light trainer.
Doesn't matter the type, or nosewheel or tailwheel. Once
you have mastered precisely controlling 70 mph on approach,
it's time to now maintain 65 mph, after wings level on final.

Then 60 mph. Nothing else has changed. Same glidepath,
same runway alignment, same flap config. All we've done
is slow the aircraft down a little bit, once we've developed
some skill at doing so, and we've scoped out the shear today.

Now what we're going to do, is land on the grass runway
beside the paved runway. It's 1,000 feet long - I mow it
myself, and I know every inch of it. With a 60 mph approach
speed, and a breath of wind down the runway, you will
find that you do not have excessive kinetic energy for a
1,000 foot real grass strip, with a ditch at the end of it.

And that, boys and girls, is how you learn to do a real
"specialty" landing. Nothing weird in the approach or
config. It all comes from precision, which is the fundamental
skill you need to develop before you go onto all those
stupid simulations on paved runways.

[Colonel Sanders]

flaps are installed to assist the pilot in reducing the speed when that is appropriate

Quite so. In a light trainer, you will typically find that
the stall speed doesn't really decrease much as you
deploy the flaps past around 15 degrees.

You don't get any more lift - only drag.

So the only time you need more than 15 degrees of
flaps is when you are doing a very steep approach
over an obstacle, and even with power off, the airspeed
is increasing.

Or, if you screw up the approach and are ridiculously
high, and even with power off and sideslip, you just
can't get it down without the help of full flap. In
which case, you should probably overshoot. However
if you are doing a PFL, well, sometimes ya gotta do what
ya gotta do (shrug). It's not something to be proud of,
though.

[PilotDAR]

Back in the '80's, I used to care for every inch of this runway, but then I moved away and built my own...





I did fly back in to visit my mom last summer. "Normal" landing with specialty precision was appropriate.

[Beefitarian]

~clicks the like button on both of pilotDAR's posts.~

If I'm going into a major center with a 5000' runway and lots of traffic, ATC asks, "Keep your speed up." I'm not using flap and probably landing long to avoid wake turbulence.

Wouldn't that be a "specialty" landing also?

Now what we're going to do, is land on the grass runway
beside the paved runway. It's 1,000 feet long - I mow it

I did that once at CYBW Springbank as a student. It was longer and the airport staff used to mow it.

I was apprehensive about it because of all the talk about, "going into a grass strip is serious business."
Then I did a near perfect soft field and gave myself unrealistic expectations of soft fields being perfectly maintained like that one.

A good dry grass strip is marvelous.

If it's been raining quite a bit or a badger has recently moved in, I have been lead to believe it may be a different experience.

[white_knuckle_flyer]

Without further getting into this silly discussion, the third part is not a disconnect..It gives a comparision of full flap to less that full flap settings. Maybe you have to read more than the tweetable first part.

I figured reading it 3 times was sufficient, and it's not like I removed every third word or anything. The one poster clearly states that he likes flaps because the decrease in energy they afford reduces the potential for ballooning. The other poster says that full flaps increase floating / ballooning potential. The only difference between them is that the first poster does not specify a flap setting. So I suggested it was one of those cases ( aviation seems to have so many of them ) where something is true up to a point (e.g.) flaps reduce ballooning and then some other truth takes over (e.g.) too much flap can actually increase ballooning potential. So I guess my rather cynical assumption was actually correct.

Newbie pilots see these posts differently. They look for consistency and patterns. If they don't get consistency then they want an explanation as to why.

[Colonel Sanders]

If it's been raining quite a bit

One of the things thats student are rarely taught
about short/rough/soft field ops (basically, anything
other than pavement) is that you don't use it unless
you walk the surface yourself ahead of time. And if
it's soft enough that anything sticks to your shoes,
don't land there.

Part of the surface may be good. Part of the surface
may be very bad (e.g. dark green grass) and must
be avoided.

If other aircraft are using the surface, it's probably
alright - eg a plowed runway on a frozen lake - but
be very careful about straying off. You are no longer
in a fisher-price playpen with rounded corners (a
certified airport).

Look at PilotDAR's pictures. The surface may be
narrow and might not be groomed like the putting
greens at Augusta, but the underlying surface is
reasonably smooth and hard, which is what matters.

[Colonel Sanders]

Newbie pilots see these posts differently

Ok, but what matters is what your instructor wants
you do to, because that's what you're going to do.

[white_knuckle_flyer]

In trainer aircraft with flaps, I like to use (and have my students
use) around 10 to 20 degrees of flaps for a "normal" landing. That generally gives them the
lowest stall speed (check your POH) ...

I just checked my POH for a 172R and the stall speed for 30 degrees is slightly lower than for
10 degrees, but the 20 degrees speed is not shown. Are you suggesting that the 20 degree speed
might actually be lower than the 30 degree speed ? ( seems unlikely in the R model since the stall speed
for power off and 30 flap is only 33 kts ). Is the relationship between flap setting and stall speed different
at powered vs power off settings ?

As far as FTUs teaching flap settings, using full flap was the only thing I was ever taught. I'm sure that is
negligent in that I was never under the impression that I should be 'managing' my flap setting...making decisions
as to when and how much. It was pretty much the robotic type of function ~ 10 flap when turning base, 20 when
turning final, 30 when established, yada yada. The idea that I didn't HAVE TO put in full flap never crossed my mind.

There was a thread on here not too long ago ( gotta find it ) where it appeared that the general concensus was that
full flaps are rarely used and that actually, full flaps come with their own host of problems unrelated to just flat landings
or crosswinds. I should go find it.

It may just be the newb in me, but I find landing with 20 or 30 flap to be easier than minimal or no flap landings. I guess
it comes down to what you struggle with the most. For me, I struggle with speed control more than flare attitude so without
flaps, I was just carrying too much speed over the runway and would land flat and fast...not good.

Anyway, that's my flap story.

[Big Pistons Forever]

Without further getting into this silly discussion, the third part is not a disconnect..It gives a comparision of full flap to less that full flap settings. Maybe you have to read more than the tweetable first part.

I figured reading it 3 times was sufficient, and it's not like I removed every third word or anything. The one poster clearly states that he likes flaps because the decrease in energy they afford reduces the potential for ballooning. The other poster says that full flaps increase floating / ballooning potential. The only difference between them is that the first poster does not specify a flap setting. So I suggested it was one of those cases ( aviation seems to have so many of them ) where something is true up to a point (e.g.) flaps reduce ballooning and then some other truth takes over (e.g.) too much flap can actually increase ballooning potential. So I guess my rather cynical assumption was actually correct.

Newbie pilots see these posts differently. They look for consistency and patterns. If they don't get consistency then they want an explanation as to why.

My experience has been that pilots learning how to fly initially do tend to balloon with full flap for two reasons. They have a tendency to let the speed build up on the last part of the approach so they end up a bit too fast and since the airplane sits in a flat attitude already the pitch down when the power is cut startles them and causes them to overcook the flare.

As for teaching Short and Soft runway procedures I think part of the problem is the FIG has you teach them right after first solo. This IMO opinion is silly as you need to learn how to do a regular landing first. I bring the so called performance landings in towards the end of the PPL. I start with Short field technique which is really just a regular landing flown slightly slower and with full flap to reduce the flare and touch down speed and then bring in the soft field technique. We start on the big runway and then move to a local strip which is narrow and 1500 feet long with obstacles.

In any case the most important part of the lesson is the PDM around how to decide if a runway is safe to operate from and the best way to approach it given the conditions.

[Colonel Sanders]

I just checked my POH for a 172R

Sorry, what I've got is a POH for a 172M which says:

Stall speed...Flaps
57 mph........0
52 mph........10
49 mph........40

Note that the first 10 flap dropped the stall speed 5 mph, but
the remaining 30 flap only dropped the stall speed another 3 mph.

I suspect that with 15 flap, you're probably around 51 mph which
is not far from the 49 mph at 40 flap.

The point is that after 15 flap, you get drag. Lots of it. And not
much more lift.

I find landing with 20 or 30 flap to be easier

Then for gosh sakes, do it! No one else can tell you what is
the best headset for you. Or whether or not you like tomato
sauce with your pasta.

[Shiny Side Up]

Personally I don't care how people have learned to land, lots of flaps, some flaps or none, as long as they can do it. What drives me figuratively insane though is how many people have been taught to modulate their approach by the use of their flaps, often as the primary means of doing so. It shows a gross misunderstanding of how to set up the approach and control it in the first place. Often with some pilots when I do check rides, stuff starts going awry on the approach and there's a "whoa, I'm really high, I need all the flaps" If I tell them they can't use them, there's always this panicked moment (where we proceed to get higher on the approach followed by their artistic interpretation of a slip and usually an overshoot.

[PilotDAR]

ATC asks, "Keep your speed up." I'm not using flap and probably landing long to avoid wake turbulence.

Wouldn't that be a "specialty" landing also?

Definitely yes, a "specialty" landing, and one of the more likely to result in nosewheel damage too. I pilot who is trying to get the plane well slowed down, and into a short runway, which is within the performance tables for the aircraft is probably safer from damaging the plane, than a pilot who is deliberately landing fast and flapless. For those times that I am asked to keep the speed up, I certainly oblige, overflying as much of the runway I feel appropriate, then performing a "normal" (ALWAYS full flap for me) landing on the portion of the runway I need to use, then clearing without delay.

I learned my lesson the startling way, landing a 182 at YYZ decades ago, where I though that with all that runway, I would just fly it on flapless. Well, I did not damage the plane, but I probably came as close as I ever have, and with a whole lot more stored energy than I cared to have to dissipate that close to the ground. That kind of landing, with the apparent "lots of room" masks a very real hazard of a careless, fast landing, and resulting ballooning, and pilot induced oscillation.

Every landing is the same - a proper approach, stabilized flare, dissipate the energy, hold the nose light, land and stop in the intended runway area. The fact that you might choose to overfly a few thousand feet of runway to do that is fine - just don't run off the end! While landing a Twin Otter on a 15,500 long runway in Africa, my Captain (who was right seat to me that day) looked over to me and said "Land long". Yes, I had figured that out!

As for WKF's observations about Cessna preferred flap settings for landing, you will find many opinions and threads on that subject, with everyone thinking they have the right answer. I do not seek to inflict my opinion on anyone, or to over ride the Cessna manuals. However, personally, after 38 years of flying just about every single Cessna out there, the only time I have ever landed with less than full flaps extended has been for zero flap practice, or during an actual flap system failure. I have never regretted choosing full flaps for landing, or felt I had less control. I have helped to clean up wrecks which were landed with less than full flap, where, in my opinion, more flap (and more pilot proficiency) would have prevented that crash. But, that's just my opinion....

And then there are flaps like this, and that's a whole different can of worms (though I still did use full flaps)

[dr.aero]

PilotDAR...

I'm not sure if I'd classify those as flaps or speed brakes...

[PilotDAR]

Interestingly, in that plane, when flying flaps 30, with someone in the back seat, the elevator, in stable level flight seems to be positioned so:



But, I'm guilty of thread drift....

[Beefitarian]

Bear with me folks. I'm lurnin™ here.

That's an excellent point that I can add flap for landing after getting out of the way keeping up my speed in the approach.

The nose wheel was not in danger at the time, I would bleed off energy with a nice long flare, land on the mains with a nice song from the stall indicator. I was pretty current when I was doing them all trip. The only problem I set myself up for, was once I got home and was fatigued from the longest day flying I ever did. I went to do one and realised my home airport didn't have nearly enough pavement. I had to overshoot and try again.

[Rookie50]

It's true -- 172 R's full flap stall is 33 kias! No wonder those things don't want to actually land. Those planes need 40....for the extra drag.

Personally, I'll reduce my flaps In a cessna single to 20 say if the wind is howling...which I define as around 25 kts or more, particularly with some crosswind component.

I just find...with less flap there is less surface for a hard gust to catch in the flare...and plane sits down a bit easier. With so much wind...plane is hardly moving anyway in such a landing.

[photofly]

If you have a lot of speed to bleed off, don't wait until you're in ground effect to do it. Do it well before the flare.

[Rookie50]

If you have a lot of speed to bleed off, don't wait until you're in ground effect to do it. Do it well before the flare.

I definitely do! -- when flying those things. It's a 55 kias approach AC.

Ive gotten used to a bit heavier stuff, and the difference power off is striking....just highlighting that. The r and s models, are like gliders to me when approaching to land...slow to lose altitude. Rg models, more like a light brick, gear down, flaps full, no power.

[white_knuckle_flyer]

Personally I don't care how people have learned to land, lots of flaps, some flaps or none, as long as they can do it. What drives me figuratively insane though is how many people have been taught to modulate their approach by the use of their flaps, often as the primary means of doing so. It shows a gross misunderstanding of how to set up the approach and control it in the first place. Often with some pilots when I do check rides, stuff starts going awry on the approach and there's a "whoa, I'm really high, I need all the flaps" If I tell them they can't use them, there's always this panicked moment (where we proceed to get higher on the approach followed by their artistic interpretation of a slip and usually an overshoot.

I only have my instructors recommended solution for flying a too-high approach. I'm interested in what your protocol is. Would you have a student slip ? Reduce power ? Nose up ? Everything ???

[PilotDAR]

I'm interested in what your protocol is

While respecting instructors here by reminding readers that I am not an instructor, I none the less have an answer for this:

Would you have a student slip ? Reduce power ? Nose up ? Everything ???

None of the above. Recognize the learning opportunity for what it is - you botched the approach, recognize that, go around, and get it better next time, 'cause now you know what bad looks like.

Though in a 172 you have lots of capacity in the forgiving design to fix a horrible approach, there are many types where you will not be able to fix the approach - the plane is just not capable. A fixably high approach in a 172,m is not fixable when flown the same way in a Cub, or Moth, or other light types. Similarly, a low and slow approach can be fixed in the 172, but would be a disaster in a twin, if you mixed it in with a failed engine.

The key is to learn to feel the aircraft, its energy, and how you are managing it. 172's are easy, other types not so willing to tell you what they are doing, or are about to do. You are learning to fly. Learning to fly a 172 is a stepping stone to this.

But, over to the instructors.....

[photofly]

I suspect that SSU's point is that you should plan your flap usage well ahead ("for this landing I will lower 10 degrees of flap abeam the touchdown point and 20 degrees having rolled out on base, and complete the approach and landing with 20 degrees of flap") and modulate your flightpath with pitch and power to arrive at the points and speeds where you planned to adjust the flaps before doing so.

Everybody and their dog has rescued an approach by throwing in some extra flap, at some time or other, but he's saying it shouldn't be taught to you as a primary means of adjusting your flight path.

Personally I don't think you need to fly a 172 as though it's a twin, or a Cub, or a Moth; if the approach is horrible but fixable, I don't think you should go around: I think you should fix it, and vow to do better next time. The key is noticing that it's getting horrible earlier and earlier, so you can take the necessary steps sooner and sooner.

[Old Dog Flying]

I'm interested in what your protocol is

While respecting instructors here by reminding readers that I am not an instructor, I none the less have an answer for this:

Would you have a student slip ? Reduce power ? Nose up ? Everything ???

None of the above. A fixably high approach in a 172,m is not fixable when flown the same way in a Cub, or Moth, or other light types. ....

Having owned a partnership in both the Tiger Moth and a Cub, The reduction of power, a side slip would be the norm to bleed off altitude on final..when necessary...all the while maintaining the centre line and the proper approach speed.

And in my Grumman AA1A, if I'm asked to keep it in close for traffic, all of the above..full flaps, reduce power, slip in the turn to final while maintaining the correct approach speed. What the hell, this is what I was taught more than 60 years ago and it still works today.

Remember the old "Attitude, Power and Trim"? or "Power, Attitude, Trim"? None of the students that I trained had problems with any of this because they had it drilled into them from the first lesson.

Barney..Old School, Old Fart

[Beefitarian]

Sorry, I should have mentioned those long landings at the busy airports were in a Warrior II, I know it flies different than a 172, the lack of floating for miles might have been crucial to what I was doing at the time.

[Rookie50]

Sorry, I should have mentioned those long landings at the busy airports were in a Warrior II, I know it flies different than a 172, the lack of floating for miles might have been crucial to what I was doing at the time.

Likely get flamed for this from the controller segment....but here it is. I have flown into a few of these busy airports with a light single, having been asked! to keep speed up "all the way in". I will do that on a long final....but at a mile....the speed comes right off.

To me, its the controllers job...to sequence the traffic properly...not to browbeat a 172 into a 100 knot short final....those kind of approaches don't work too well. Better to slow it down, land, get off the runway quickly.