Downside of taking off with flaps?

[N184DA]

I only use flaps in my RV4 for takeoff when I have a rear-seater.
Makes it easier (& quicker) to transition from the three-point attitude.

[AlexPeterson]

I've used about 1/3 to 1/2 flaps for almost every takeoff, maybe 2200 of them so far. My flap switch is just to the left of the throttle knob, so I only have to move my thumb over to put them up once I see about 70-75 knots. I like the visibility over the nose better during the initial airborne phase, and the airplane is in trim during the transition from just airborne through 130 knot climb speed, without changing the trim position much. The liftoff speed is a bit slower, and comes a lot sooner with some flaps in.

On a go around, it will be very unlikely that I'll forget to raise the flaps, as it is a normal procedure for me (as others have mentioned).

Disadvantages: takes a bit higher groundspeed to lift the nose wheel, and a flight would need to be aborted if the flaps didn't come up.

[KRviator]

I use flaps every takeoff, no exceptions and peg the speed at Vy for the first 30 seconds no matter where I am. That, typically, gets me high enough I can return to the runway.

My home strip is grass & gravel, short, on top of a plateau and surrounded by trees, exactly the place you do not want an engine failure. The faster I can get higher, the better the chance I have of being able to clear the trees and make it to a clearing or nearby road.

[gereed75]

Thanks for the food for thought Mel.

Although the airliner example is certainly true, it is a bit apples to oranges to our case. Our fat short Hersey bar wings perform very differently than an airliner wing optimized for high altitude cruise. A no flap takeoff in a 767 would take a LOT of runway.

AFAIK L/d max is achieved flaps up. Never flew any best glide profiles with the flaps partially down. Yep you may produce more lift at the same speed with partial flaps, but you will also produce more induced drag.

Simple test might be timing successive take offs, 0 to 80 knots, 80 knot climb to 300’. There might be some combination of partial flaps that get you there quicker, but I suspect it will be within a few seconds either way.

[andrewtac]

https://vansairforce.com/community/s...d.php?t=134158

I believe flaps 10 in the 8 was the best compromise, which I do on all takeoffs.

[gereed75]

Mark, Thanks for that link. Very interesting data, thanks Nigel.

Interesting that with that data, Nigel and a couple of other sage flyers stated a choice to do normal take offs from paved runways no flaps. I also suspect that most people use a higher airspeed than 1.2 Vs during climb out on TO. The nose attitude at 1.2 Vs would not be a fun place to be with a sudden engine failure after TO.

Again, many pros and cons to weigh here.

[RV6_flyer]

Have read this thread a couple of times.

I rarely use flaps except on grass. I have forgotten to retract flaps taking off on pavement once. The amount of trim needed is how I knew flaps were down.

Starting to think about using flaps more often to become more like Mel developing a reflex action check to make sure they are up.

[Pilot135pd]

Originally Posted by Mel

Flaps are not only for drag. They also produce lift. Why do you think airliners use flaps for take off? On the RV series of aircraft the range of 15° flap is pretty close to best L/D. At this point you are producing more lift than drag.

With proper use of flaps, you will be at a higher altitude when your failure occurs.

Another good post where I would have used a LIKE button here if it were available instead of posting to say I AGREE.

[AAflyer]

I quickly transitioned to using flaps during takeoffs in my -8, ...
it seems to reduce/eliminate the "skittering around" just prior to liftoff.

[Pilot135pd]

Originally Posted by AlexPeterson

Disadvantages: takes a bit higher groundspeed to lift the nose wheel, and a flight would need to be aborted if the flaps didn't come up.

I'd move it to the ADVANTAGES. Wouldn't it be better to know your flaps aren't working as you depart your home base instead of finding out when you use them to land at another airport and then find out they don't retract?