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How long do you wait to retract flaps on takeoff?


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Flap retraction  

116 members have voted

  1. 1. When do you retract flaps on takeoff?

    • I don't use flaps on takeoff
      13
    • Before gear retraction
      1
    • Right after gear retraction
      29
    • Once clear of obstacles and comfortable
      48
    • 100ft AGL
      3
    • 200ft AGL
      1
    • 300ft AGL
      3
    • 400ft AGL
      6
    • 500ft AGL
      7
    • Over 500ft AGL
      5
    • On Crosswind
      0


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We had a poll about flap retraction after landing. But what about after takeoff? When do you retract the flaps? Do you regularly use flaps on takeoff? Only on short takeoffs or all takeoffs? What determines when to retract.

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I consider a positive rate of climb (PRoC) to be the absolute determining factor and a MUST before flap retraction.

PRoC should be in your poll Mike. You don't you even mention it?!

I retract flaps once I have a PRoC and clear of any obstacles.

PRoc, gear up, flaps up.

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Let me ask this... do you reference the altimeter in your decision to retract takeoff flaps?

 

That's why I included option "Once clear of obstacles and comfortable" as a general catch all that is not determined specifically by altitude.

 

For example when I was training, instructors would forbid me to retract flaps before a specific altitude or to turn before a specific altitude. I don't operate that way in my Mooney. I don't know what altitude I retract my flaps at so I wouldn't be able to give a number. It is more of a feel thing for me that includes being clear of obstacles, having sufficient altitude for comfort, and feeling confident that the airplane will continue climbing despite a momentary loss of lift during retraction.

 

As to the dentist's point, I don't see it as particularly relevant. I don't think anyone is going to argue to retract flaps while sinking. And most of the points presume you have positive rate of climb in order to be at that altitude or condition. Positive rate of climb alone is probably not a good reason for retraction (such as just climbing out of ground effect).

 

And those of you voting "right after gear retraction," I'm curious if you could add at what point you retract gear. Cause obviously there's a big difference between retracting when leaving the ground, no runway left behind, and reaching a certain altitude prior to retraction. I'm sure if you go "positive rate of climb, gear up, once gear is up, flaps up" you'd have gear and flaps up before hitting 100ft in most of our birds!

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None of the selections; all of the selections.

Depends on what I'm doing after takeoff.

If I'm climbing straight-away, generally pretty quickly.

If I'm making a turn right after takeoff, I leave the flaps out to provide a bit better stall margin at a lower airspeed to keep the turn radius smaller.

If I'm concerned about obstacle clearance, I might delay retraction until clear, but accelerating to clean climb speed may be a better solution depending on how far away the obstacles are.

Just depends.

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I wait for the airspeed to pass 80 knots and with positive acceleration and rate of climb. Years ago I took off out of an airport out of Colorado Springs in a C182 I had at the time an retracted the flaps a little prematurely. I was maybe 50 to 75 feet above the runway. I darn near sunk and bounced off the runway. After that I give myself quite a bit of extra buffer in high DA take offs before I retract them now. Since I mostly take off at sea level it seems like the faster I retract them the faster I go:)

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I use TO flaps at short fields for my weight on that departure. Home is 3000' long, normally no flaps unless near gross. A nearby grass strip is 2000', I always use flaps and don't go in or out anywhere near gross--2 people and half tanks is my limit.

Positive rate, gear up; clear of obstacles, flaps up is in my Owners Manual. Both are judged looking out the window, with a glance at the IVSI if I'm near gross, hot, windy, worried about DA, etc. Clear of obstacles usually means the trees have gone behind the leading edge and I'm happy with the vertical space betwixt me and them. Positive rate, flaps up could hurt you . . . Not good if you're heavy, high DA or gusty winds . . .

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As to the dentist's point, I don't see it as particularly relevant. I don't think anyone is going to argue to retract flaps while sinking. And most of the points presume you have positive rate of climb in order to be at that altitude or condition. Positive rate of climb alone is probably not a good reason for retraction (such as just climbing out of ground effect).

 

 

 

I think his point is spot on.  It's obvious that no one is going to retract during a negative climb rate but it is entirely possible and probable during certain conditions to be stagnant in climb and that is certainly not a good time to retract the flaps.  Therefore his theory on when "he" chooses to do things is right on the money!   It's certainly more of a technique than what you state yours is:  "it's a feel thing"  Good luck using that one climbing into IMC right after lift off.    :P

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I consider a positive rate of climb (PRoC) to be the absolute determining factor and a MUST before flap retraction.

PRoC should be in your poll Mike. You don't you even mention it?!

I retract flaps once I have a PRoC and clear of any obstacles.

PRoc, gear up, flaps up.

This is the answer I was looking for.

Once airborn beyond the point of landing safely,gear up.

PROC and clear of obstacles,flaps up.

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I consider a positive rate of climb (PRoC) to be the absolute determining factor and a MUST before flap retraction.

PRoC should be in your poll Mike. You don't you even mention it?!

I retract flaps once I have a PRoC and clear of any obstacles.

PRoc, gear up, flaps up.

 

that's what my cfi taught me for the flaps.

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I like to be clear of all obstacles and on the north side of 100 MPH before I retract takeoff flaps.

Jim

Exactly, Jim. This for me happens between 200 and 500 AGL. I have no hard procedure for it, although I do recognize that if it wont fly faster than 145 MPH IAS after level off, the flaps arent up

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I look for 90mph before retracting flaps and if I'm light I just suck them up with the flip of the switch but if I'm heavy ill inch them up a bit of a time.

I think it obvious positive rate has already been established.

If the goal is to go up and build speed and not to go up to quickly by sacrificing airspeed and not to not go up and build airspeed so I think 90mph gives best of both worlds.

Also below 90mph I think the extra angle of attack needed to maintain the same fpm climb creates more drag than leaving the flaps I'm take off position.

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