Flap retraction during landing roll
- Thread starter ColMustard
- Start date
unless absolutely necessary (such as the cases already mentioned--go around/balked landing/short or soft field T/O's) no. Its a habit thing. While i agree that at a certain point the aircraft could brake better with out lift being created by the flaps but unless you are flying into a short strip, you really shouldnt need to get all that braking performance. Cessna/Pipers have landing distances of like 1150 feet. Hardly enough to warrant really needing to get on it for a piece of tarmac thats 2000+ feet long.
As you go up in aircraft that take longer distances its hard to say...especially when your specific aircrafts AFM may or may not have landing data for anything other than full flaps. The data in there is specific to a certain configuration and by changing that you are not guaranteed better performance and by most accounts it will be worse.
Leave them where they are untill stopping is assured and work load permits or clear of the runway if at all possible.
As you go up in aircraft that take longer distances its hard to say...especially when your specific aircrafts AFM may or may not have landing data for anything other than full flaps. The data in there is specific to a certain configuration and by changing that you are not guaranteed better performance and by most accounts it will be worse.
Leave them where they are untill stopping is assured and work load permits or clear of the runway if at all possible.
ColMustard
New Member
Doug Taylor said:
Point taken Doug, thanks.
I'm leaning more and more to the side of leaving the flaps alone until clear of the runway, and the after landing checklist is in hand.
-ColM
fourierman
New Member
I'm not sure why its ok to retract flaps, turn off carb heat, etc. during a touch and go reconfig while rolling along on the ground at 30-40 kts versus it not being a suggested action when your decelerating from 40kts to 0 for a full stop , taxi-back, etc.
I guess I think way too much into this stuff!
I guess I think way too much into this stuff!
desertdog71
Girthy Member
fourierman said:
I was thinking the same thing, How are you going to do a touch and go, without retracting flaps, carb heat, power in.
I like to hold the nose off, and bleed the speed down, until the yoke is into my chest. Then retract flaps, carb heat, power.
I see the point of leaving them alone, but is it not sometime wise to get them retracted, like high winds, crosswinds and that sort of thing? I know that rolling ailerons into and away from quartering winds is emphasized. Isn't an extended flap just as likely to get some air under it, and flip you?
Good discussion. However I did notice that Doug says to leave them alone, and I am pretty sure he has about a million more hours than me.
Minnesota_Flyer
New Member
Well, in a touch & go, you have a good reason to bring the flaps up while moving. On most full stop landings, there simply isn't any good reason to be messing around with the flaps while the aircraft is rolling.fourierman said:
Also, the real trouble comes when you move up to retractable gear aircraft. The danger of accidentally grabbing the gear lever is real, and happens all too often. I've yet to fly someplace that allows touch & gos in a complex a/c for this reason.
MF
Holding Short
Well-Known Member
New here, long time lurker.Finally registered. Aaannnyyy waaaayyyyy, I always thought that the squat switches on the gear are suppose to prevent the wheels from folding. But, I do agree with not retracting flaps on the roll out. Only for special situations like touch & go's, short field's etc...Minnesota_Flyer said:
HS
B767Driver
New Member
Single Engine Piper manuals suggest that wing flaps should be retracted after touchdown for maximum braking.
The FAA's Airplane Flying Handbook says on page 12-17...."After the short field touchdown, maximum stopping effort is achieved by retracting the wing flaps, adding back pressure to the elevator/stabilator, and applying heavy braking. However, if the runway length permits, the wing flaps should be left in the extended position until the airplane has been stopped clear of the runway. There is always a significant risk of retracting the landing gear instead of the wing flaps when flap retraction is attemted on the landing rollout."
My personal observation...is that in the motion to retract the flaps...especially Piper airplanes...the pilot relaxes back elevator pressure which does more to mitigate braking than retracting the flaps. One of the biggest mistakes I see small airplane pilots make is not holding full aft elevator after landing...bad things are going to happen if the controls are not held full aft.
I spent a couple of summers instructing out of a grass field. I would recommend retracting the flaps in this situation, because flaps could take some damage from rocks, dirt, etc...that could cause some damage.
The FAA's Airplane Flying Handbook says on page 12-17...."After the short field touchdown, maximum stopping effort is achieved by retracting the wing flaps, adding back pressure to the elevator/stabilator, and applying heavy braking. However, if the runway length permits, the wing flaps should be left in the extended position until the airplane has been stopped clear of the runway. There is always a significant risk of retracting the landing gear instead of the wing flaps when flap retraction is attemted on the landing rollout."
My personal observation...is that in the motion to retract the flaps...especially Piper airplanes...the pilot relaxes back elevator pressure which does more to mitigate braking than retracting the flaps. One of the biggest mistakes I see small airplane pilots make is not holding full aft elevator after landing...bad things are going to happen if the controls are not held full aft.
I spent a couple of summers instructing out of a grass field. I would recommend retracting the flaps in this situation, because flaps could take some damage from rocks, dirt, etc...that could cause some damage.
caliginousface
Frank N. Beans
Holding Short said:
the dutchess and i'm sure other aircraft don't have squat switches, but they rely on a certain airspeed to determine if the motor will cycle the gear selection.
CapnJim
Well-Known Member
B767's post is excellent.
I'm split, so here's my General Rule of Thumb: If the plane has a gear lever, don't fiddle with flaps on the runway. If it dosen't put 'em up, if you want.
Here's a related side-note story about squat switches:
I remember this girl on her commercial checkride at my old field. She was in a Cutlass, a 172RG. End of the chekride, everything good so far, all that was left was a soft field demonstration. She floats in and squeaks it on, nose high in the air-- perfect. Then she went to put the flaps up.
Now, at this point I should tell you that the Cutlass landing gear squat switch is located on the nose wheel, and that the gear lever is located perilously close to the flap lever, but that would wreck the story, wouldn't it?
"Too late! Too Late!" will be the cry, when the Flatulent Man passes you by!
The Cutlass's complex gear system, whose perfectly functioning squat switch was unfortunately still high above the runway, obligingly folded the mains aft and up, the nose pulled into its well, and the Cutlass settled onto its belly, stopping the engine and prop on the runway surface after less than 2 1/2 turns. Poor girl. Poor Cutlass.
On the other side of the coin, I've won many a landing contest in a plain-vanilla 172 by flipping the flap lever up just after touchdown. Also keeps things a bit more stable on the ground in gusty and cross-windy conditions. Useful stuff in spring at a place like F50, if you've ever been there.
So my opinion is, like lots of other things in aviation, there's not always hard and fast rules. That's no fun anyway. Better to use knowledge, experience, and good judgment.
I'm split, so here's my General Rule of Thumb: If the plane has a gear lever, don't fiddle with flaps on the runway. If it dosen't put 'em up, if you want.
Here's a related side-note story about squat switches:
I remember this girl on her commercial checkride at my old field. She was in a Cutlass, a 172RG. End of the chekride, everything good so far, all that was left was a soft field demonstration. She floats in and squeaks it on, nose high in the air-- perfect. Then she went to put the flaps up.
Now, at this point I should tell you that the Cutlass landing gear squat switch is located on the nose wheel, and that the gear lever is located perilously close to the flap lever, but that would wreck the story, wouldn't it?
"Too late! Too Late!" will be the cry, when the Flatulent Man passes you by!
The Cutlass's complex gear system, whose perfectly functioning squat switch was unfortunately still high above the runway, obligingly folded the mains aft and up, the nose pulled into its well, and the Cutlass settled onto its belly, stopping the engine and prop on the runway surface after less than 2 1/2 turns. Poor girl. Poor Cutlass.
On the other side of the coin, I've won many a landing contest in a plain-vanilla 172 by flipping the flap lever up just after touchdown. Also keeps things a bit more stable on the ground in gusty and cross-windy conditions. Useful stuff in spring at a place like F50, if you've ever been there.
So my opinion is, like lots of other things in aviation, there's not always hard and fast rules. That's no fun anyway. Better to use knowledge, experience, and good judgment.
Texasspilot
New Member
If you going to do it make sure your using a positive phrase such as "FLAPS UP" while you glance to identify it. I flew with a guy recently who had become way to lax and aftertakeoff threw the gear up and reached over to pull the props back and accidenly grabbed the mixtures instead and brought them about 50% lean when he slammed them back in. This was at about 200AGL past the end of the runway.
It would have been a lsing situation for sure.
It would have been a lsing situation for sure.
frog_flyer
FredFlyer
its probably been answered above, but this is reponse to initial post
they say retract flaps on landing roll for short field landings. decreased lift = more weight on wheels for more effective braking
also pull back on yoke to raise elevators to do the same thing
its shiner sunday!!
they say retract flaps on landing roll for short field landings. decreased lift = more weight on wheels for more effective braking
also pull back on yoke to raise elevators to do the same thing
its shiner sunday!!
JaceTheAce
Well-Known Member
Pay attention to landing the airplane first, then retract the flaps after you cross the hold short line on whatever taxiway exit you choose. Then do your afterlanding checklist (flaps included), then call up ground, done.
Unless you're landing on a 600 foot runway where maximum breaking is required, I doubt you'll need to retract the flaps in order to "stop sooner". Even then I doubt you'd save any more than 2 feet worth of breaking.
Unless you're landing on a 600 foot runway where maximum breaking is required, I doubt you'll need to retract the flaps in order to "stop sooner". Even then I doubt you'd save any more than 2 feet worth of breaking.