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Retracting flaps after landing

Kokemiller

Kokemiller

Well Known Member
Just wondering how many of you make it a standard practice to retract the flaps as soon as you touchdown. I know it reduces aerodynamic braking and wouldn't be good practice on short field landings but it does have some good advantages:
1. Makes it easier to keep the nose off longer (don't notice this in the 7A but it makes a big difference in the 9A)
2. In case of a go around the flaps are already up
3. Less debris beating up the bottom of the flaps
4. Reduces chances of gusts making you airborn again.
5. Increases braking effectiveness as less lift puts more weight on tires.
 
I do a lot of short field landings on strips and for me dumping flaps is standard practice.

Not only because I get a lot of paint chips in the flaps if I don't: My ground roll is greatly reduced; I can apply brakes in a way more aggressive way.

jm2c as usual..
 
N4744Z said:
I know it reduces aerodynamic braking and wouldn't be good practice on short field landings
Click to expand...

Actually the addition of brake effectiveness outweighs aerodynamic braking at landing speeds. My home strip is 1500' and is considered short by many. I ALWAYS dump flaps immediately on touch down. And as you say, it also reduces the probability of going airborne again.
 
Yes.

...I'm a manual dumper (so I can make the bravo turn off by where I hangar).
 
I don't. I am concentrating on keeping the nose wheel off the pavement then slowly letting it down. I minimize braking and am not usually hard on them to get off at any specific turnoff. Once I turn off I usually raise them to minimize the chance of debris damage. Note sure that it is a big hazard with wheel pants.
 
Flaps tend to push the nose down. It is easier to hold the nose up with the flaps retracted.
 
Raising flaps after a landing-Yes

...but for a different reason. Having had the famous flap motor quit working happen a time or two, I want to know the flaps are up while taxiing IN, rather than while taxing OUT with baggage and pax loaded for flight. It's just one less hassle.
 
While I don't disagree with retracting the flaps on the landing roll out on a short field landing which is proper technique, if any of you fly with a CFI and in a retractable gear plane, don't be surprised if you get your hand slapped while retracting the flaps on roll out.
 
The flap switch is the first thing I hit when the wheels are down. Makes it easier to keep the nose up, allows it to stay up longer, and still lets the nose down easy. With the nose up, the aerodynamic braking is fine. Also, with the 9, having the flaps up protects the wing/flap joint as you enter/exit. I am always afraid of someone stepping on that back two inches of the wing (not the flap) and damaging it. Fixing a flap is easier than fixing a wing.

Bob
 
I retract mine on landing but then when taxiing will drop them back down about 10 degrees. That makes it more obvious to passengers that they shouldn't step on the flaps either getting in or out (even though I always tell them not to step anywhere except the black wingwalk square).

greg
 
Just an interesting observation here....the responses that folks are going to give on this topic are probably influenced greatly by whether they have manual (almost instant retraction) or electric (about 6 -7 seconds full travel) flaps, and whether they are lying a tail or nose dragger (getting in to a tail dragger with flaps down is much easier, and less prone to damage flaps, while the nosedraggers with steps might be the other way around).

In my experience, if I hit the flap retract switch on my -8 at touchdown, the braking improvement is negated by the slow flap retraction time - 6 seconds is a lot of braking time before the flaps are up, so I question the benefits, especially since I am going to lower the flaps again to facilitate loading and unloading (Not to mention the cost of flap actuators should you wear one out due to double-cycling them....). I always retract the flaps before engine started, after loading, to make sure they'll go up, and to prevent dings from prop-driven gravel or debris.

of course, with a good old "Johnson bar", you can dump the flaps instantly to get benefit on touchdown and roll out, them drop them just as quickly once you're parked. A benefit of manual flaps, for sure!

Paul
 
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Retraction

Capflyer said:
While I don't disagree with retracting the flaps on the landing roll out on a short field landing which is proper technique, if any of you fly with a CFI and in a retractable gear plane, don't be surprised if you get your hand slapped while retracting the flaps on roll out.
Click to expand...

Although I will not argue the practice in an RV, I am one of those CFIs that will "slap" you in a retractable of any kind. Way too many embarrasing moments involving inappropriate gear retractions on the ground. The rule at my airline was that nothing was touched until you were clear of the runway, not even light switches.

John Clark ATP, CFI
FAA FAAST Team Member
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA
 
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N4744Z said:
Just wondering how many of you make it a standard practice to retract the flaps as soon as you touchdown. I know it reduces aerodynamic braking and wouldn't be good practice on short field landings but it does have some good advantages:
1. Makes it easier to keep the nose off longer (don't notice this in the 7A but it makes a big difference in the 9A)
Click to expand...
Ummm, I don't really have this problem as my little wheel in the back.

N4744Z said:
2. In case of a go around the flaps are already up
Click to expand...
Not an issue. The RV's are so over powered that with the flaps down, GW, and a hot day they will climb at a very impressive rate.

N4744Z said:
3. Less debris beating up the bottom of the flaps
Click to expand...
This would be the reason I retract mine.

N4744Z said:
4. Reduces chances of gusts making you airborn again.
Click to expand...
Never gave that much thought but when doing three point landings, even a small gust can get the -9 flying again.

N4744Z said:
5. Increases braking effectiveness as less lift puts more weight on tires.
Click to expand...
I hope to never land so long and fast that this is an issue. See #2 above.

The truth is, as long as it takes to retract the electric flaps (~9 seconds), by the time they come up enough to make much difference aerodynamically, you are going so slow it wouldn't matter very much. I would much rather focus on landing the plane and getting it slowed down than worry about raising the flaps.

One thing of note, on soft/wet grass I will taxi with them down in hopes they will give me enough lift to prevent me from getting stuck.
 
This might be a whole other topic but ...

How much flap you use during landing. I normally land with 1/2 flaps unless I've mis-judged the approach and feel like I need to increase my sink rate.
 
John Clark said:
Although I will not argue the practice in an RV, I am one of those CFIs that will "slap" you in a retractable of any kind. Way too many embarrasing moments involving inappropriate gear retractions on the ground. The rule at my airline was the nothing was touched until you were clear of the runway, not even light switches.

John Clark ATP, CFI
FAA FAAST Team Member
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA
Click to expand...

John,

I was about to say the same thing...:)
 
Rick_A said:
How much flap you use during landing. I normally land with 1/2 flaps unless I've mis-judged the approach and feel like I need to increase my sink rate.
Click to expand...
Rick, this will be different by plane but with my -9 I put them all in abeam the touch down point. I then simply adjust pitch (speed) and power (touch down point) as needed.
 
Flaps

Capflyer said:
While I don't disagree with retracting the flaps on the landing roll out on a short field landing which is proper technique, if any of you fly with a CFI and in a retractable gear plane, don't be surprised if you get your hand slapped while retracting the flaps on roll out.
Click to expand...

OK, point taken, but we're talking RV's here!
 
Rick_A said:
How much flap you use during landing. I normally land with 1/2 flaps unless I've mis-judged the approach and feel like I need to increase my sink rate.
Click to expand...
SOP for me is one notch abeam the numbers, one more on base, and the last one or two on final, depending on how high/low I feel at the time. Manual flaps, with notches at (approximately) 10, 20, 30, and 40. Most of the time 30 is all I use.

Most of the time I raise 'em on landing once i'm established on the ground... On my home grass strip, which bounces around from time to time (yes, it's the runway, not the pilot) having that extra bit of lift removed makes sure I stay on the ground.

We have airports here with taxiways that have lights quite close to the edges too... A -6 with flaps down will clear between them with about 1-2' on each side, so it's safer to raise them.
 
In our two pilot ship, the copilot reconfigures at touchdown for max nose wheel lift (retract flaps), fuel pump off,lean for taxi, only when the aircraft is under control and clear cold. Single pilot is no different, don't touch anything until either off the runway or stable airborn again.
 
videobobk said:
The flap switch is the first thing I hit when the wheels are down. Makes it easier to keep the nose up, allows it to stay up longer, and still lets the nose down easy. With the nose up, the aerodynamic braking is fine. Also, with the 9, having the flaps up protects the wing/flap joint as you enter/exit. I am always afraid of someone stepping on that back two inches of the wing (not the flap) and damaging it. Fixing a flap is easier than fixing a wing.

Bob
Click to expand...
So how comes 8 out of 10 leave the flaps on 10 degrees down position when parked, as we often see on airshows? I thought the reason was to prevent passengers to step on the flaps when entering or exiting the aircraft.
 
If you leave the flaps all the way down when parked, and if a spectator leans against your flaps while admiring your cockpit, it's possible to flex them just enough to allow the top skin of the flap to pop free from behind the top skin of the wing. Just enough that it will catch when you go to retract the flaps later.

Raising the flaps to 10 or 20 degrees means that you still have a visual reminder to not step there, and looky-loos can't set you up for an ugly or expensive repair later on.
 
If I had manual flaps I would probably lift them. When I build an -8 I will add the "one-push-to-flap-up" switch. The last thing people need to be in a habit of doing is taking their hand off the throttle to hold a flap switch for 7 seconds in a tail dragger. If it's an electric flap machine and a true short field the aircraft will be stopped by the time the flaps fully retract anyway.
 
Here's what I have been doing.

Approaching the airport/pattern.

As soon as I slow the airplane to 80KIAS I add 10 degrees flaps. No matter where I am at in time and space. I find that the -9 has a rather nose down feel to it in cruise and when I slow to 70-80 KIAS it has a slight nose high feel. The 10 degrees of flaps keeps the nose in a slight nose down attitude. Plus it allows for a little more rpm which in WI helps with shock cooling.

Abeam

When I am abeam my landing point, I dump full flaps unless there is significant wind. Then I stay at 10 degrees. Add more if needed on final.

On the runway

I don't usually pull the flaps up, but then I am on a 5800 ft paved surface usually. On a short/ soft field, once I have it under control I will bring the flaps up.

Now here's my story, My son and I were landing on a short/soft and very uneven strip lined with corn fields on either side. I touched down and was going to do a 180 for a back taxi and immediate takeoff. At about 20 kts or so, I started to move left for a my RH 180, however the 20 degree LH turn put me aimed at the corn and we had a RH 15kt cross wind. Just as I was correcting right the runway fell away from under us and I was nearly airborne, with no braking action heading straight for corn. Yikes, I stood on the rudder and managed to keep it from an early corn harvest. Barely! Had I been in the habit of raising my flaps on the soft-fields on touch down, I doubt this would have happened. I, like Mr Clark, have taught my students not to touch anything until we are clear of the runway. In fact that is my flight schools policy. However, from now on, in my RV, my students will be taught, to raise the flaps on soft fields on touch down. (they can raise the gear if they like)
 
The landing gear switch on my RV-6 (Yes, I have one) is on the upper left of the instrument panel. My flap switch (the very long one as on the original RV-6) is between the seats. Not much danger of confusing the two.
 
Mel said:
The landing gear switch on my RV-6 (Yes, I have one) is on the upper left of the instrument panel. My flap switch (the very long one as on the original RV-6) is between the seats. Not much danger of confusing the two.
Click to expand...

Um... Ok, I'm relatively new here. Why do you have a landing gear switch on your -6? :confused:
 
sbal0906 said:
Um... Ok, I'm relatively new here. Why do you have a landing gear switch on your -6? :confused:
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I fly retracts regularly and using the switch keeps me in practice.
I have the switch, warning light and horn. I have used it religiously for over 17 years.
 
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Mel said:
I fly retracts regularly and the switch keeps me in practice.
I have the switch, warning light and horn. I have used it religiously for over 17 years.
Click to expand...

Thanks for the explanation. It makes sense and is a good idea.

Cheers,
 
John Clark said:
Although I will not argue the practice in an RV, I am one of those CFIs that will "slap" you in a retractable of any kind. Way too many embarrassing moments involving inappropriate gear retractions on the ground. The rule at my airline was that nothing was touched until you were clear of the runway, not even light switches.

John Clark ATP, CFI
FAA FAAST Team Member
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA
Click to expand...

Mel said:
The landing gear switch on my RV-6 (Yes, I have one) is on the upper left of the instrument panel. My flap switch (the very long one as on the original RV-6) is between the seats. Not much danger of confusing the two.
Click to expand...

rjcthree said:
Do you call down and welded on final? :p

Rick 90432
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I USE to do what most of the others do. Was flying with a CFI that slapped my hand when I touched the flaps in my RV-6 because of it being a bad habit in a retract. I now NEVER touch anything till clear of the runway (except for opening the canopy on a HOT South West Summer day)

Mel is not the only guy that has a switch like that in a fixed gear airplane. I helped designed what Mel is talking about minus the horn to keep a friend in the habit for retracts. I gave him LEDs, resistors, switch, 9-volt battery clip, and Velcro to attach it to the airplane.

Yes I do call DOWN AND WELDED in the pattern. Boost pump, Gas, Undercarriage, Mixture, Prop (on short final)
 
What should I do? I am keeping my RV6A at home on my grass strip that is 1600' or so and I alway's have left my flap's down after touch down. From what I have been reading here I should put them up as soon as I touch the grass? That will not make my roll out longer on landing but shorter? I do have manual flaps and it seem's like as soon as I touch the grass I slow down pretty fast. I just started landing here at home this fall so I am new to this short field stuff. So I fell like I am doing pretty good but I keep telling myself it will be different in the summer with less lift.
 
Don't change

m3tt5 said:
What should I do? I am keeping my RV6A at home on my grass strip that is 1600' or so and I alway's have left my flap's down after touch down. From what I have been reading here I should put them up as soon as I touch the grass? That will not make my roll out longer on landing but shorter? I do have manual flaps and it seem's like as soon as I touch the grass I slow down pretty fast. I just started landing here at home this fall so I am new to this short field stuff. So I fell like I am doing pretty good but I keep telling myself it will be different in the summer with less lift.
Click to expand...

The theory being expressed is that by raising the flaps, and killing some lift, you put more weight on the wheels. Which, on pavement, could be a factor. On grass, the "traction' is low to nonexistent (wet grass) but the trade out is the drag from the grass itself helps slow the airplane.

John Clark ATP, CFI
FAA FAAST Team Member
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA
 
m3tt5 said:
What should I do? I am keeping my RV6A at home on my grass strip that is 1600' or so and I alway's have left my flap's down after touch down. From what I have been reading here I should put them up as soon as I touch the grass? That will not make my roll out longer on landing but shorter? I do have manual flaps and it seem's like as soon as I touch the grass I slow down pretty fast. I just started landing here at home this fall so I am new to this short field stuff. So I fell like I am doing pretty good but I keep telling myself it will be different in the summer with less lift.
Click to expand...
If you're making good landings on your grass strip now, don't worry about it, and don't change what works. But if you find (as I do) that slight bumps in the grass strip are enough to put you back in the pattern, you'll find that selecting flaps up as soon as you're established on the ground will keep you there.

Note: Don't select flaps up to try and fix a bad bounce... It'll just make the next one worse. Fix the bounce first, then when you're down smoothly bring the flaps up.
 
Considering I will probably never fly a RG airplane and raising the gear in a RG glider takes a LOT of work (swap flying hands, twist hard to unlock gear lever, pull gear up), I will happily continue to dump the flaps on landing when needed.

TODR
 
Bounce

Snowflake said:
But if you find (as I do) that slight bumps in the grass strip are enough to put you back in the pattern, you'll find that selecting flaps up as soon as you're established on the ground will keep you there.
Click to expand...

If the bump puts you "back in the pattern," you might want to rethink your approach speed. :D

John Clark ATP, CFI
FAA FAAST Team Member
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA
 
John Clark said:
If the bump puts you "back in the pattern," you might want to rethink your approach speed. :D
Click to expand...
I agree, and i'm working it down as time passes. My home circuit has a very tight turn on one end, and i'm leery of taking that too slow right now... I don't mind admitting that I need the extra margin because i'm not that good yet.
 
Snowflake said:
I agree, and i'm working it down as time passes. My home circuit has a very tight turn on one end, and i'm leery of taking that too slow right now... I don't mind admitting that I need the extra margin because i'm not that good yet.
Click to expand...

Rob,

Here is something that will give you a lot of confidence and safety when flying the tight, slow pattern:

http://thervjournal.com/liftreserve.htm

This is a great way to reduce approach speed while insuring a margin of safety.
 
I land my 9A with full flaps and leave them fully extended for parking and tiedown. I use 10 degrees of flaps for takeoff. At the slow speed the 9s land, I don't feel raising the flaps to increase brake effectiveness is a concern.
Keeping the flaps down:
1. reduces the number of cycles on the flap motor
2. makes boarding the a/c much easier
 
It's all about approach and touch down speed....

I am a disciple of any type of AOA device for safe pattern work.

If the indicator is moving toward the no-fly zone I know more speed will be needed soon, the back pressure relaxed a bit in the turn and/or add power. It is the cats meow for making a minimum speed approach.

A few days ago it was 59 KIAS (well inside green AOA) across some tall trees and right on down to the flare point. Landed and made a turn off in 1500' minus about 600' to clear the trees and flare with very little braking. That will work only if touch down is at or near the 51 knot stall speed of my machine. No time to retract the flaps as they are electric so they stay at 40.

Most of the time I can't do it that short because of turbulence and/or cross wind, but once in a while in really smooth air, it is fun. :)

(All compliments of Dynon D10-A AOA)
 
I went up Thursday and thought I would try a couple landing's takeing my flap's out as soon as I touched on both grass and hard surface. For me I could not tell much difference. I alway's us full flap's when I land and my airspeed coming over the aproach is about 60mph. I hope I am doing everything right.
 
At OSH 2009, I asked this question to Mike S, who has the most logged hours of any pilot in the world in RV'S.................

he said......" full flaps in a 6 is all drag and no lift". Take it from there.
 
9A Flaps Up after landing

After reading this thread I started raising my flaps soon after landing and have found that with my 9A I can keep my nose in the air as long as I want when I keep the airspeed about 25mph. And its very easy to control direction with the rudder. My forward visibility is not impaired by the higher nose angle.

Yesterday I made a landing to a partially snow and ice covered runway at 3M7 and was able to keep the nosewheel away from any snow and ice bumps on the runway and able to steer easiely to the melted areas and at the last minute drop the nose and make my turn to the ramp.

Anything to keep the stress off the nosewheel is always welcome.

BTW my flap switch is on my stick and easy to utilize.
 
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Not quite true!

gasman said:
he said......" full flaps in a 6 is all drag and no lift". Take it from there.
Click to expand...
If that were the case, stall speed would be the same with full or no flaps.
I will agree that full flaps do not have any more lift than 2/3 flaps. My stall speed is slower at 13? flap, and slower yet at 26?. At 39?, stall speed is the same as 26?.
Therefore adding full flaps gives you more drag than 2/3 flap but no MORE lift.
 
Mel said:
If that were the case, stall speed would be the same with full or no flaps.
I will agree that full flaps do not have any more lift than 2/3 flaps. My stall speed is slower at 13° flap, and slower yet at 26°. At 39°, stall speed is the same as 26°.
Therefore adding full flaps gives you more drag than 2/3 flap but no MORE lift.
Click to expand...

isnt' that all different in ground effect?

with no flaps it puts more weight on the gears , and "kills" lift (allowing brakes to be more effective, less skidding tires, etc) or this is how I was taught....i didn't know it varied much from airframe to airframe

having said that, i am training with not touching the flaps until either positive rate, or clear of the runway......but I want to do commercial next, so it's habit building for me anyway
 
Mel said:
If that were the case, stall speed would be the same with full or no flaps.
I will agree that full flaps do not have any more lift than 2/3 flaps. My stall speed is slower at 13? flap, and slower yet at 26?. At 39?, stall speed is the same as 26?.
Therefore adding full flaps gives you more drag than 2/3 flap but no MORE lift.
Click to expand...

What Mike was saying is to leave the flaps down during your roll out to help slow the aircraft down. The full flaps create more drag than lift, and would be no benefit to retract to help braking by reducing lift.

Not so with a 8A or 10 with empty rear seats. The fwd cg will cause the nose to drop sooner than if one notch were retracted after touch down or landed with one less notch.
 
Sometimes you need drag

gasman said:
At OSH 2009, I asked this question to Mike S, who has the most logged hours of any pilot in the world in RV'S.................

he said......" full flaps in a 6 is all drag and no lift". Take it from there.
Click to expand...

Yes, but there are extreme situations, where what you need is just that, DRAG. It allows you to come in like a paraglider, hanging more on power than on wings, on the limit. All you need to stop after touch down is chop the power...
 
This is an easy one for me. I have a simple flap switch that must be held in the direction of flap transition. The flaps will stay in the position they are in when I let go of the switch. I need my two hands to fly the plane when landing and will not sacrifice my attention to hold the switch while the flaps retract. In my 9A I have not yet found a situation where I needed to get the flaps up or down faster than the switch will allow but would like one that is a simple up/ 1/2 down and full down but the plane was completed when I bought it and I have been told it is tough to change the set-up. AM I WRONG?

Thanks, Ken
N63EB
RV-9A/CS/195HP
 
Sunriver Ken said:
This is an easy one for me. I have a simple flap switch that must be held in the direction of flap transition. The flaps will stay in the position they are in when I let go of the switch. I need my two hands to fly the plane when landing and will not sacrifice my attention to hold the switch while the flaps retract. In my 9A I have not yet found a situation where I needed to get the flaps up or down faster than the switch will allow but would like one that is a simple up/ 1/2 down and full down but the plane was completed when I bought it and I have been told it is tough to change the set-up. AM I WRONG?
Click to expand...

My flap switch is next to the throttle. It works the same as yours, but takes care of the two hand problem, since it's easy to work flaps and throttle with the right hand........at the same time.

L.Adamson --- RV6A
 
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