Runway Length for no Takeoff Flaps

[201er]

What runway length and/or weight configuration is the cross over point from when you use takeoff flaps to not use them? I've found myself using takeoff flaps at all but the longest runways because I'm mainly used to flying from short fields where they are necessary. So I use them most of the time and don't realize when I could have went without them.

[M016576]

Quote: 201er

What runway length and/or weight configuration is the cross over point from when you use takeoff flaps to not use them? I've found myself using takeoff flaps at all but the longest runways because I'm mainly used to flying from short fields where they are necessary. So I use them most of the time and don't realize when I could have went without them.

[carusoam]

When you need "book" number performance, follow the "book" configuration.

When the runway is long enough that you don't need a calculator to do the math...Weight, temp, wind and altitude...you are free to experiment, but do so at longer runways until you know how well your ship works.

3,000' is usually long enough for east coast comfort.  Decision making at halfway allows you to continue or stop in the remaining length.

There is not much difference between no flaps and t/o flaps, in terms of performance.  There is real advantage in lowering the stall speed though.

What is the advantage of not using T/O flaps?  Now you have two take off procedures with two sets of data and no decision tree on when to use which procedure.

In my M20C, I never used t/o flaps, but I never went into fields where distance was in question.

In the R, I want to follow the one procedure with the full data set that accompanies it.

That's my logic, YMMV...

Best regards,

-a-

[HopePilot]

Does anyone change their takeoff flaps for higher density altitude situations?  I've always used partial flaps, as I did today at Big Bear.

[1964-M20E]

I’ve only used TO flaps a few times just to experiment but I generally operate out of 3000+ fields.  Once I inadvertently took off with full flaps and close to max weight.  The plane (64 M20E) behaves very weird in that configuration but it will take off and climb.  Not the best method but I did learn from it.

[GeorgePerry]

Quote: JimR

I always use takeoff flaps in my 201. I just see no reason not to. They are especially helpful on manual gear Mooneys, however, in that they help keep the speed down so that it is easier to get the gear up. 

 

Jim

[Hank]

My home field is 3001', and I only use TO flaps in my C if I'm loaded heavy in warm weather.

When I visit a nearby 2000' grass strip, I usually have TO flaps, but flying solo it makes little difference.

It all comes down to:  how does your plane perform, and how comfortable are you with the given circumstance? There is nothing wrong with using them all the time.

[Shadrach]

Bob Kromer says he likes the way "it feels" to take off no flaps.  Much as I enjoy Bobs writing, this is another subject on which we disagree.  I prefer the "feel" of the airplane with TO flaps. I prefer the shallower climb angle (for a given ROC) and the increase in forward visibility with TO flaps, as well as the increased stall margins.

A few months ago I had an interesting take off from an 1800ft turf field. It was quick turn and after unloading I taxied to the end of the runway for departure. After leaning for take off (DA was around 2700) and set TO flaps. I then second guessed myself on the latching of the baggage door so I leaned over and popped the passenger door to check that the baggage door was secure (it was). In the process, I unknowingly bumped the manual flap retraction lever with my leg. Clearly I made it out, but it was mushy and initial climb-out was at a very low angle and rate. Every time I tried to raise the nose, the stall horn protested. It was not until I reached over to raise the flaps that I realized why the plane had performed so oddly.

There is no reason in my mind for no flap take offs. I'm not saying that they are dangerous, but they do decrease margins and for what benefit? None that I can see. 

[Hank]

Ross--

No flaps makes for a nice, gentle takeoff and it will fly off on it's own if I don't rotate. Like Bob says, it feels good, at least in short-bodies. I've only ever had the stall horn squeak when the winds are gusty, and that just means I didn't hold her on the ground long enough. Typical performance is 200+ agl around 3000' from the line [field = 3001'; 10' to the red lights; 10' more to the road cut; then a shoulder and two lanes. Call it 3100-3150' total, minus the displaced threshhold since there are trees there].

[Shadrach]

Quote: Hank

Ross--

No flaps makes for a nice, gentle takeoff and it will fly off on it's own if I don't rotate. Like Bob says, it feels good, at least in short-bodies. I've only ever had the stall horn squeak when the winds are gusty, and that just means I didn't hold her on the ground long enough. Typical performance is 200+ agl around 3000' from the line [field = 3001'; 10' to the red lights; 10' more to the road cut; then a shoulder and two lanes. Call it 3100-3150' total, minus the displaced threshhold since there are trees there].

[jetdriven]

I have done both and the aircraft climbs positively with takeoff flaps.  With flaps up, any bump or yoke movement sets off the stall horn. It also has an anemic rate of climb for the first few feet until you get over 80 MPH.  Laminar flow wings just have high drag and low lift at low speed.

  I feel in the flaps up configuration and a rather high takeoff weight, the aircraft can settle on the back side of the power curve and never accelerate, just like those A36 Bonnazas can.

[RJBrown]

I always set flaps to takeoff position on my J. When I had the Rocket it just did not care. Acceleration was so quick that the flaps went from helping to hurting in no time at all. At Cenntennial I would have the gear up 100KT+ and 1000+ FPM before I was off the airport.

[PilotDerek]

I'm in the always set takeoff flaps group. Just don't see a reason not too and it'll become muscle memory so you never forget them. Trying to figure out if runway length is adaquate to use/not use just doesn't make sense. There is a reason why there is a setting for takeoff on our flaps indicator and checklist. Always side on the side of safety.

[jlunseth]

I don't use takeoff flaps any longer unless the field is short enough that it looks like a short field takeoff situation, and that would be under 2400 or with obstacles at the end.

When I use takeoff flaps, there is a distinct pitch up when I raise the gear, and then a very distinct pitch up when I raise the flaps.  Need to be rolling the electric trim full down at the same time I raise the flaps.  They just are not necessary unless you are going to be doing a Vx climb and therefore have a reason to lower your stall speed. 

[bd32322]

I do not use T/O flaps for the same reasons jlunseth mentions above - large pitch changes and the aircraft leaves the ground better without them (less flat attitude - so seems less like its jumping off the ground). I am sure different model years behave differently though given the responses above.