Coyote wrote:... it makes you lighter on your feet so the breaks have relatively less weight to bring to a stop during the process. Splane that to me

You have the same amount of weight to bring to a stop, only now less of it is resting on the tires, so slowing the rotation of the tires has less overall affect. Take the argument to it's logical conclusion and that's why the airplane doesn't slow down if you hold the brakes in flight...none of the weight of the airplane is resting on the tires, so stopping them from rotating has no affect.

Flaps do provide drag, but providing the weight of the airplane is resting on the tires, brakes are infinitely more effective than the aerodynamic resistance of the flaps, especially at the slow speeds our airplanes land at.

Thanks Hammer I see it now. Eventually the breaks must stop the entire weight of the plane and full flaps just delay that process. Aerodynamic breaking is only a minor contributor overall.

Hammer wrote:
Flaps do provide drag, but providing the weight of the airplane is resting on the tires, brakes are infinitely more effective than the aerodynamic resistance of the flaps, especially at the slow speeds our airplanes land at.

+1 for the most part

The aero engineers could run all the calculations to quantify it, but I think it is a safe bet that there is a point where the two curves (aerodynamic drag decelerating the airplane, and brake effectiveness vs. weight on the tires) cross. On one side of that crossover point the flaps slow the airplane down best. On the other side of that crossover you get more out of the brakes with enough weight on the tires. Also, having better directional control (weight on the tailwheel, AND not having the flaps "blank out" the fin and rudder) is another advantage of flap retraction. If someone is landing on a narrow, or wet/muddy, or side-sloping strip, directional control can become the primary concern.

I feel bad for all the Luscombe, J-3, 7AC, and C-120 guys sitting on the sidelines for this epic debate.

Zzz wrote:I feel bad for all the Luscombe, J-3, 7AC, and C-120 guys sitting on the sidelines for this epic debate.

I've tried, but have found that it is too distracting trying to find the flap handle in the 7AC during landing.

Wow! Page 6 Let's see if I can't add some more grist to the mill:

I usually stay in two-point attitude until at walking speed using brakes, so I tend to not raise flaps until my tail is down.

Since the goal is lower angle of attack in order to improve braking and/or control in gusty conditions, I wonder if raising flaps and therefore lowering the tail (on most taildraggers) wouldn't actually be counterproductive, since now the entire wing is at positive angle of attack.

The bigger the tires, the greater the angle of attack. Seems like an argument for just staying in two-point attitude / neutral angle of attack for as long as practical and leaving flaps down until the tail is down.

Let's see if we can't get to page 7!

(I know the OP flies a 150. Just having fun.)

AND not having the flaps "blank out" the fin and rudder) is another advantage of flap retraction. If someone is landing on a narrow, or wet/muddy, or side-sloping strip, directional control can become the primary concern.

It sounds counter-intuitive, but a technique taught to me a long time ago for dealing with heavy crosswinds (flaps up/flaps down, tri-gear or conventional gear) is as brakes are applied and speed across the ground decreases, rudder effectiveness decreases, which is then countered by more and more throttle to bring the rudder back to life.

Up north in the Sleds, I would often find myself coming to a stop on the runway with a 30+ kt crosswind and the RPMs way high. Not really consciously, but pushing/pulling controls because it made the airplane behave like I wanted. All part of using what you got to make your airplane do what YOU want it to do.

Gump

Whatever works Gump,

With the wide runways in the lower 48 and a 30 kt crosswind, I usually just angle across the runway and come to a full stop before the upwind edge without touching the brakes. But then, I didn't have brakes until I got smart enough to quit flying my own and start flying other peoples airplanes. By that time I already had developed the habit.

Contact

True. But with narrow, not oriented to the prevailing wind runways like we had in the Arctic in a lot of the villages, you were stuck with what you had. Nice thing was, they were all gravel, or snow and ice. Slippery runways can be your friend in crosswinds.

And the free help with ground speed is nice.

C'mon guys... I'm trying to get ya to page 7.

Gump

I'll play if it will help get to page 7.

I think that with some airplanes staying in a two-point with flaps out might create less lift than raising the flaps and lowering the tail. A super-cub on 31's for example...huge tires and pretty marginal flaps, so maybe. A fowler-flap Cessna on 29's...probably not.

Since most airplanes need more room to take off than to land, the only time I'm really worried about maximizing my short field performance is when I'm dealing with less than favorable winds...a tail wind at a one-way strip, or strong cross winds that require a higher rate of closure to maintain directional control.

In those cases my proclivity, right or wrong, is to immediately raise the flaps and get my tail wheel on the ground as firmly as possible.

What I do wonder about in normal operations is whether leaving the flaps down and the tail up will reduce rock strikes to the the tail feathers. Most of the time that's more important to me than landing shorter.

page 7 here we come! To really land short I have heard the proper technique is to leave the flaps down and catch a bobwire fence with the tailwheel kind of like those crazy guys that land on big boats. I have heard with no brakes it will stop a 170 in 100 ft.

I've done it. and sometimes I don't.

Zzz wrote:I feel bad for all the Luscombe, J-3, 7AC, and C-120 guys sitting on the sidelines for this epic debate.

Yeah, I wish I had something to add. Never really learned how to use flaps and never worried about it when flying the Luscombe. During the 30 something hours in the Bearhawk I just kinda made it up; sometimes I put them up during roll out, sometimes I left them out, sometimes I forgot I had them so didn't use them at all. Guess I got lucky and didn't end up in a smoking hole off the end of the runway.

If you are really trying to stop short and I mean SHORT!! Than in a cub you would drop the flaps tail will stay up and maybe go over the top if you brake hard enough. If you drop the tail and brake hard flaps up or down the plane will skip due to lack of weight on the mains from higher AOA. If you watch the 2014 Valdez STOL video on U-tube you will see the cub with the belly pod hit his spot on first pass but could not stop short due to the skipping. His wife is my brothers sister-in-law. I hear is trying to work up the balls keep the tail up when braking hard like the winners do.
DENNY

GumpAir wrote:

AND not having the flaps "blank out" the fin and rudder) is another advantage of flap retraction. If someone is landing on a narrow, or wet/muddy, or side-sloping strip, directional control can become the primary concern.

It sounds counter-intuitive, but a technique taught to me a long time ago for dealing with heavy crosswinds (flaps up/flaps down, tri-gear or conventional gear) is as brakes are applied and speed across the ground decreases, rudder effectiveness decreases, which is then countered by more and more throttle to bring the rudder back to life.

Up north in the Sleds, I would often find myself coming to a stop on the runway with a 30+ kt crosswind and the RPMs way high. Not really consciously, but pushing/pulling controls because it made the airplane behave like I wanted. All part of using what you got to make your airplane do what YOU want it to do.

Gump

Gump
That is useful sometimes when the brakes have no affect and the only thing holding you in place it the prop!!
Gump some have never experienced a slick glass landing on wet ice!!
Kind of like sailing in the crosswind with a seaplane but on wheels!

Hammer wrote:

Coyote wrote:... it makes you lighter on your feet so the breaks have relatively less weight to bring to a stop during the process. Splane that to me

You have the same amount of weight to bring to a stop, only now less of it is resting on the tires, so slowing the rotation of the tires has less overall affect. Take the argument to it's logical conclusion and that's why the airplane doesn't slow down if you hold the brakes in flight...none of the weight of the airplane is resting on the tires, so stopping them from rotating has no affect.

Flaps do provide drag, but providing the weight of the airplane is resting on the tires, brakes are infinitely more effective than the aerodynamic resistance of the flaps, especially at the slow speeds our airplanes land at.

That flat tire Rob posted probably a good case for retracting flaps, he probably saw the end of the runway coming up fast and had no weight on his mains for braking and burnt a hole in his tire. Or he just came in to hot. Typical nose wheel pilot. just kidding! Doing my part to continue the thread.

Well, I don't have anything more to say than what I did on page 1, except to say that I never expected the discussion to go on and on like it has. It has been interesting to see the different perspectives. And of course, if I can possibly help the thread to get over the 7 page hump, well, I've done my dooty, right?

Cary

I raise my flaps after landing so I don't hit my head on them repeatedly getting out of the plane. C'mon page 7!