Edited to sound less pompous:

I have worked with very skilled young pilots who habitually retract flaps on touchdown to make the brakes more effective, and they all had one thing in common: they aspired to be "Bush Pilots". Ironically, this technique works well on paved and packed strips, but really starts to unravel in loose gravel, mud, snow and ice. In other words, the "Bush". To sum it up, unless your landing surface provides good braking, you will inevitably land longer when retracting flaps.

Flying sleds in Western AK, I used this technique for longer than I care to admit but it wasn't until I got into heavier and faster airplanes that the reality sunk in: Dumping flaps increases wear and tear on landing gear and tires, reduces elevator and rudder effectiveness on many aircraft types, gives away aerodynamic braking (which at 40+ knots is far more important than whatever braking you can get from your tires), and destabilizes the aircraft by shifting center of lift and attitude at the most critical phase of landing.

Recently, while teaching someone to land a 180 on asphalt, I had the student surprise me by dumping flaps on touchdown in an effort to prevent the plane from bouncing. He succeeded in sticking the touchdown, then we nearly groundlooped from the resulting high-speed three-point rollout. We had an animated conversation about communication our intentions after that.

Show them this this it might help https://www.youtube.com/watch?v=UjwCcQq38i8

At Valdez, there were different methods employed. Breeden retracts. Claus does not. Holley retracts, the winning Helio does not. The second place 185 retracts, and the third place hillbilly in the multicolored 180 does not retract, but he probably married his own sister, so who knows. Competition flying is educational to watch, and proof that there are many ways to skin a cat.

elgoatropo wrote:I suspect this topic could ruffle some feathers, but it's worth addressing if it prevents bent metal. Don't mess with the flaps on rollout. Occasionally it makes sense in extreme crosswind gusts which make it difficult to keep the wheels down. Also in certain low-wing types, flaps tend to incur gravel damage when down. But shearing your landing gear off will result in even more gravel damage.

I have worked with very skilled young pilots who habitually retract flaps on touchdown, but they all had one thing in common: they aspired to be "Bush Pilots". But they had picked up a cheap trick that green instructors pass on to unsuspecting students as some kind of special Alaskan Bush technique, and when somebody sitting in the right seat surprises me by "helping" and retracting my flaps, its time for a gentle reminder that we are not done flying when the wheels touch the ground.

Flying sleds in Western AK, I used this technique for longer than I care to admit but it wasn't until I got into heavier and faster airplanes that the reality sunk in: Dumping flaps increases wear and tear on landing gear and tires, reduces elevator and rudder effectiveness, gives away aerodynamic braking (which at 40+ knots is far more important than whatever braking you can get from your tires), and destabilizes the aircraft by shifting center of lift and attitude at the most critical phase of landing.

Recently, while teaching someone to land a 180 on asphalt, I had the student surprise me by dumping flaps on touchdown in an effort to prevent the plane from bouncing. He succeeded in sticking the touchdown, then we nearly groundlooped from the resulting high-speed three-point rollout. We had an animated conversation about communication our intentions after that.

I dont suspect the topic will ruffle feathers but the way you approach it might. You have some valid points and obviously quite a bit of experiance. I'll fly my airplane how I want, you fly yours how you want, and if we ever fly together, we'll make sure communicate about how it will be flown

Thanks Jared. I edited my post to make it sound a little less condescending. I am still changing the way I fly after 10,000 hours, and I am always looking to learn new things. Just the other day, I started using 10 degrees of flaps to taxi in 206s, because of something I read here on this site. I tried it, and I liked the result it gave.

What are some good reasons for retracting flaps on touchdown?

In my 172, I do it because I like unloading the wing and keeping it solid on the mains. I also like it because it provides a realy quick and easy transition to go around if needed on rollout. I dont believe in 172 that Im adding any stress to the gear.

Jared: I like your reasoning as it relates to preparing for the go-around. What do you think about Contact's thoughts on flying the plane as long as possible? My dad always told me, "fly it all the way to the tie-down." He is a taylorcraft guy, so he means that literally. My trademark saying is something like, airplanes make lousy cars. Keep the weight on the wings as long as possible. Somewhere along the way, I started operating like I was always on a short/soft field, even on a 10,000' paved runway. Maybe it was because the mains on the clapped-out 402s we ran shimmied so bad.

Quote from Contact:

"In strong crosswinds I use the same apparent rate of closure approach and angle across the landing zone or runway to take some of the crosswind out. On the ground with a tailwheel ac I may need help after stopping, but everybody has to stop sometime. Slow, full flaps if you have them, reduces damage to airplanes in any condition. Gust spread is mitigated with as much throttle control as necessary to maintain glide angle. Where there are no approach obstructions, slow to shake at the lowest ground effect possible and then hover taxi to the landing site works best. Gradually slowing using the brisk walk rate of closure makes it possible to take some of the strong crosswind component out safely because you will come stop very quickly in a strong headwind/crosswind. Brakes are a ground operation tool. With the free slowing of a strong crosswind/headwind, the airplane is flying at near zero groundspeed. If we fully use the wing (and full flaps if available,) we take advantage of the best characteristics of our airplane. They fly much better than they race along the ground. It is critical, during this approach, that all directional (longitudinal axis) control is all dynamic, proactive rudder and independently all drift control is wing only. On a steep approach over obstructions, the wing needs either be kept level with aileron or banked as necessary into the crosswind. In the hover taxi approach, the wing must be kept level to keep it out of rocks and stuff. With the hover taxi approach, we have to change to the side slip to put the upwind main wheel down first in the appropriate bank. This is over smooth ground or the first part of the runway."


I would stop short of saying dumping flaps is never useful. It is a useful tool for 207s in some circumstances, given its unusual geometry. Several winners at Valdez employed this technique. But I hate to see flap-dumping and heavy braking used to cover up a lousy approach, or the inability to land without bouncing. You can get away with it for a while, but brakes are no substitute for airmanship.

In my earliest training some 41 1/2 years ago, I was taught to leave the flap lever alone (electric in several 150s and a pair of 172s), because my instructor used to say, "someday you'll fly a retractable, and you don't want to accidentally raise the gear when you mean to raise the flaps". That was good enough for me, and so I passed that onto my students later on--and when I was flying retractables, it was certainly good advice to follow.

Most of my experience until I bought my current airplane was with electric flaps in various airplanes, both fixed gear and retractables (or older Mooney hydraulic flaps), except for a few hours in various PA28 versions with manual flaps. I continued to follow my first instructor's mantra, to leave the flaps alone after landing until it was time to either reconfigure to take off again after a stop and go, or after leaving the runway to taxi to parking.

When I bought my current airplane (63 P172D with manual flaps), I thought I'd try "dumping" the flaps after touchdown, but I found I tended to wobble because of the reach involved to go to zero flaps. So for the last 10 years, I've just left them alone, just like I was taught, until reconfiguring to take off again or taxiing to parking.

I really don't think it makes enough difference to worry about, one way or the other. The real key to making landings short is final approach airspeed control, not relying on either aerodynamic drag or heavy braking. Most of the time, I seem to be able to do that!

Cary

Elgoatropo: Re: flying the airplane as long as possible: I dont follow contacts way of thinking sometimes or his terminology, such as "hover taxi". I dont fly helicopters. When I intend to land, I pick a spot, put the airplane there and I want the airplane to be done flying as soon as possible once I touchdown. I almost always make a full stall landing and i dont retract the flaps to makeup for a poor approach or landing. Also, a nice long taxi is a good chance to cool down the engine and cleanup the office. If I wanted to land in front of the hangar, I would fly a helicopter.

I'll bet you can make a shorter gravel landing in that 172 if you try it this way:

Approach slow and steep, behind the curve so that you have to carry a little power on final. When the mains touch, simultaneously apply light braking and increase elevator back pressure to balance the airplane on the mains with the nosewheel just kissing the runway. Once you have the yoke in your lap, close the throttle fully, and brake to a stop using moderate braking. Feel the considerable drag caused by the downwash from the flaps being redirected upward by the elevators. You should be able to stop in less than 200 feet at sea level.

If you watch the Valdez video above at 32:20, you will see my friend Ben land his 172 in 137 feet in ten knot gusts using this method.

elgoatropo wrote:I'll bet you can make a shorter gravel landing in that 172 if you try it this way:

Approach slow and steep, behind the curve so that you have to carry a little power on final. When the mains touch, simultaneously apply light braking and increase elevator back pressure to balance the airplane on the mains with the nosewheel just kissing the runway. Once you have the yoke in your lap, close the throttle fully, and brake to a stop using moderate braking. Feel the considerable drag caused by the downwash from the flaps being redirected upward by the elevators. You should be able to stop in less than 200 feet at sea level.

Next time I'm out, Ill play with your suggestions. Thank you. Now I just need someone to show me how to takeoff in 200 ft

Don't hate on the rotor heads! Lol

Jeredp wrote:

elgoatropo wrote:I'll bet you can make a shorter gravel landing in that 172 if you try it this way:

Approach slow and steep, behind the curve so that you have to carry a little power on final. When the mains touch, simultaneously apply light braking and increase elevator back pressure to balance the airplane on the mains with the nosewheel just kissing the runway. Once you have the yoke in your lap, close the throttle fully, and brake to a stop using moderate braking. Feel the considerable drag caused by the downwash from the flaps being redirected upward by the elevators. You should be able to stop in less than 200 feet at sea level.

Next time I'm out, Ill play with your suggestions. Thank you. Now I just need someone to show me how to takeoff in 200 ft

I agree with you there Jered. As fun as it is to land short, its really not that practical because most of the planes we fly need more room to take off.

I always retract after the second bounce.

Hover taxi in an airplane is very slow flight in an airplane and is only possible in very low ground effect. I'm trying to fuse, not confuse.

I have a profound theory. Sometimes its better to retract, sometimes its not.

"Always" statements I have found tend to lead down a long path toward a piece of humble pie. There's only a small number of items requiring "always".
My humble opinion is unless your a high time pilot well in tune with your plane or in a situation where its needed, then yes, just leave em alone until everything's under control. Especially in a manual flap like a 180 that tends to throw some people off trying to mess with them while alot is going on. Most of the time its not necessary. But like many things. It's another specialty tool you can use in the right place at the right time.
I've heard some say also that full flaps for take off is never necessary. There's a whole other can of worms to be opened.
To each his own. When I find something that works for me I'm not to concerned about others telling me its useless. I have found used for both of these in certain instances and uses properly.

55wagon wrote:I have a profound theory. Sometimes its better to retract, sometimes its not.

"Always" statements I have found tend to lead down a long path toward a piece of humble pie. There's only a small number of items requiring "always".
My humble opinion is unless your a high time pilot well in tune with your plane or in a situation where its needed, then yes, just leave em alone until everything's under control. Especially in a manual flap like a 180 that tends to throw some people off trying to mess with them while alot is going on. Most of the time its not necessary. But like many things. It's another specialty tool you can use in the right place at the right time.
I've heard some say also that full flaps for take off is never necessary. There's a whole other can of worms to be opened.
To each his own. When I find something that works for me I'm not to concerned about others telling me its useless. I have found used for both of these in certain instances and uses properly.

I think I might have to copy this, and bust it out as needed, with whatever topic is at hand substituted wherever it says "retract flaps".
-DP

55 Wagon's response nailed it! Perfect!

I agree with these wise words. In fact, the behavior I am criticizing here is this:

Automatically doing something that you saw a bush pilot do. Making it so automatic, that you assume it is the only way, to the point that you would be so bold as to dump someone else's flaps for them when they appear to have their hands full with the throttles and yoke.

As a young pilot, I pulled this trick on my boss in a BN2A Islander landing on a beach in moderate turbulence. He would have been justified in leaving me behind on that beach.