View Full Version : Flaps up on Takeoff

12th Sep 2012, 15:05
Hello a recent post got me thinking about this could some aircraft accomplish this?I've heard the 757 can do it at least in an AA sim.I know the 737,727 and Md-80 definitively can't as has been seen before any other types that you think might manage it?Obviously all aircraft could get to a flaps up Vr should the pilot know whats coming,the runway be long enough and the tires be able to stand the heat.I'm talking about a situation with a normal take off where the aircraft could takeoff at or near to a normal Vr speed and then climb out successfully.

12th Sep 2012, 20:33
Fokker 100..

12th Sep 2012, 21:13
Flaps up? 737 and 767's. The flap handle will be in a T.O./ flap extension slot but you won't necessarily have any flaps extended. Leading edge devices? Yes. Flaps? No because Flaps 1 on some models is actually just leading edge slats with no flaps.

In the sim I've done no flap takeoffs in approx. 7 different airliners. Attempt rotation at normal Vr speeds with no flaps. :eek:

Speed, low angle of attack, and ground effect are your friend. :ok:

Try to 'make it' climb and you won't read the next day's headlines... which will be all about you. :ooh:

12th Sep 2012, 21:18
Flaps up T/O may work.

Gear up landings also.

But why to try?

12th Sep 2012, 21:24
With a long enough runway, any aircraft could take off at Flaps Up. After all, they CLIMB flaps up don't they? Most just aren't certified to do so, as there is no advantage in doing so as opposed to using slats and flaps.

The reason there have been accidents is because there have been inadvertent Flaps Up take-offs, while using the calculated Flaps/Slats at takeoff settings V speeds, thus trying to get airborne too slow for the actual configuration.

12th Sep 2012, 22:25
Thanks,using ground effect works if you know its coming but if you don't and climb normally in most aircraft you're in trouble.I know about flaps 1 on some aircraft is only slats I used flaps as its more of a general term I guess.Thanks for your input I appreciate it what type of aircraft have you tried it on and what were the results,if you get a second?

12th Sep 2012, 23:50
you are making the assumption that wings generate lift...

13th Sep 2012, 01:41
At or near to a normal Vr? No. The Vr is tied to the flap setting and weight and attempting to rotate below the appropriate Vr for your flap setting won't end well (expect anything from a tail strike to a runway overrun). There's no reason you couldn't get it flying if you had the correct Vr, enough runway, and you didn't exceed the tyre limit speed though.

13th Sep 2012, 03:46
Gulfstream - sim work is typically done around max landing weight so it's not like you're at the runway limited weight.

Results? No big deal if you delay rotation until V2 to V2+15 and climb out at approx half your typical pitch attitude. If you try a normal rotation and climb out of ground effective you could be in a world of hurt.

"Speed is life". Fighter pilot saying. Especially true if you forgot your leading edge devices. Flaps aren't as big a deal. Slats alone are 50-70% of the total stall reduction from clean to full landing flaps.

13th Sep 2012, 05:16
Depending on which authority you're flying over, the Global (5000, Express and XRS) can do a "clean" takeoff. Normally we use slats and 6 degrees of flap. Calculation for the clean takeoff is convoluted so they're almost never done.

I imagine that a major limiting factor is the tyre speed. Too fast and they delaminate.

13th Sep 2012, 05:28
When i took my first flying lessons in the beginnings of the 90's for my CPL/ATPL, i did all my first months-basis on a Cessna 152 before transiting to the "bigger" Tampico & Trinidad. I always remember my School ground instructors and flying ones, that the Standard procedure for take off on a normal RWY for a 152 its Flapless. Before changed to TB9 and TB20 and later to the Twin ones, i always did it and learned it without flaps...of course, later on those were only nice Cessna Memories:)

13th Sep 2012, 07:12
The Concorde took off with no flaps/slats on every flight (it didn't have any!)

It did have some droop built into the leading edge, along with other aerodynamic refinements, that gave some of the effect of slats at low speeds without compromising the clean form needed for supersonic flight.

Vr was ~178-197 kts depending on weight. With special tires to handle the higher speeds.

At the other end of the scale, the original Piper J3 Cub also had no flaps. But as with janetflight's 152, Vr for small planes is usually about 50% of their maximum cruise speed. The much smaller (2:1) speed envelope means they can operate flapless throughout the envelope if desired - with the option of forward slip to induce sink on final.

A 757 (et al) flown J3-style with no high-lift devices for takeoff would also rotate at about 50% of max. cruise (in the thick air inhabited by 152s and J3s ;) ) - or about the same speeds as the Concorde.

13th Sep 2012, 08:29
Depending on which authority you're flying over, the Global (5000, Express and XRS) can do a "clean" takeoff. Normally we use slats and 6 degrees of flap. Calculation for the clean takeoff is convoluted so they're almost never done.

I imagine that a major limiting factor is the tyre speed. Too fast and they delaminate.

It is not a clean take-off, it's a zero flaps slats out take-off.

No complicated calculations, it's right there in the QRH.

But you need the SB done that permits the use of the procedure(tyres, etc.)

13th Sep 2012, 15:46
I have done a Flap 0 t/o on a 737-400 sim. At about 140kt, we set 10 degrees nose up and waited for it to lift - This occured at 180-190kt if memory serves me right after using lots of runway!

In other words, no where near anything like a normal Vr!

14th Sep 2012, 21:47
Thank you all for your very interesting responses and opinions I greatly appreciate it:).

galaxy flyer
15th Sep 2012, 07:17

What airline did no-flap T&Gs in recurrent? I did several bounce drills in the 3-holer at EAL, we didn't do any no flaps landings even. Mus have been thrilling!

galaxy flyer
15th Sep 2012, 18:25
Or a C-model Hun!

EDIT------Oops, couldn't do T&Gs in a single-seater. I knew that, DOH!

Idle Thrust
16th Sep 2012, 14:33
My mob was very slow to buy the B-727 so for a number of years we flew the DC-9-32 on legs much longer than it was really designed for. In order to get the required fuel and payload into the sky we bought zero flap T/O data from Douglas and used it quite often on certain segments. Slats were of course extended.

This used to produce some interesting R/T at U.S. airports:
"Uh, Air Canada, this is XXX behind you - you know that you have no flap out?"
"Y'all going flying that way?"

On a hot summer day those little nosewheels sounded awfully close to their critical speed underneath the floor!

16th Sep 2012, 15:33
Fascinating thanks for your input:D