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related questions:

My question focus on passengers jets (goes from Embraer E-jet family to Airbus A380). I don't know why pilots would attempt to takeoff without flaps but lets say they will.

Considering all the other parameters are good enough (no crosswind, long runway, aircraft light enough,...) and the pilots are aware of this unusual takeoff configuration and adapt their action accordingly (including increasing $V_r$ and $V_2$), is it possible for any passenger jet to takeoff and stay airborn (not like the flight spanair 5022) without extending flaps?

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Manu H
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    As for why it could be because the flaps are inoperative and no facilities for repair exist. – ratchet freak Oct 17 '14 at 10:20
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    An important aspect to this questions is not whether or not it is possible, but whether or not it is legal, with manufacturer approved procedures and performance data. – Lnafziger Oct 17 '14 at 16:12
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    @Lnafziger Indeed, but my question do not adress the reasons of such takeoff, only its possibility (I think the reasons require another question) – Manu H Oct 17 '14 at 16:35
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    Also, one other aspect you may wish to consider in this question is whether or not it is possible without slats as well, since they are generally used together and for the same reasons. – Lnafziger Oct 17 '14 at 17:08
  • This is an opinion-based question, except for a test pilot who might in a position to make no-flap departure in transport class aircraft – rbp Oct 17 '14 at 20:41
  • @rbp Not if there is a procedure for it. :) – Lnafziger Oct 17 '14 at 21:55
  • @rbp as highlighted by other comments, this question is not about the reason of such non standard take off. – Manu H Oct 18 '14 at 07:47
  • @Lnafziger but its not a question about a procedure for a specific airplane, but about "passenger jets" in general, and any answer is speculative – rbp Oct 26 '14 at 14:35
  • @ManuH i never mentioned anything about reason. this is an opinion-based question and any answer would have to be an opinion. – rbp Oct 26 '14 at 14:37
  • @rbp I disagree. I asked if it is technically possible, i.e. if it has been done at least one. A possible answer could be "yes, a test pilot has already made it". The answer by hokkuk highlight a possible extension to the question about condition of such takeoff. – Manu H Oct 27 '14 at 08:06
  • I've edited the question to match the comment – rbp Oct 27 '14 at 14:33
  • The answer could be its yes its been tried on a model aircraft or no so this is a good question – securitydude5 Feb 14 '18 at 18:51
  • @securitydude5 -- model airplanes take off without flaps all the time – quiet flyer Aug 15 '20 at 15:04

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Yes take-off without flaps is possible. The Airbus A300 and Boeing 767 are approved for such take-offs and it is being done regularly. It results in a better climb gradient, especially with one engine out. The one engine out climb gradient is an important and sometimes limiting factor in take-off calculations.

One important constraint is the length of the runway.

Another limitation, perhaps less obvious, is the maximum rolling speed of the wheels. The tires are rated to a limited speed which may be exceeded by a flap-less take-off.

DeltaLima
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    Are you sure the 767 is "no flaps" as opposed to "flaps 1"? Flaps 1 moves the SLATS to the mid position, but no adds no flaps. Flaps 5, 15, 20 add flaps as described. Flaps 25 and 30 move the slats to the second position, and the flaps as described. – rbp Oct 17 '14 at 20:37
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    @rbp "no flaps" as in "adds no flaps". Slats are required IIRC. – DeltaLima Oct 17 '14 at 20:53
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Thanks to DeltaLima for the Answer, I want to add the Fokker 100 to the Planes with no-flaps take-off capabilities. But as said you need a higher take-off speed. also stated in table:enter image description here

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you can make a brick take off without flaps, if you put enough power behind it, and those jets have enough power, (as long as the runway is long enough for those particular hunks of metal)

a good question can be added on, how long of a runway does a 'xxx' need with half load, with empty load, with full load and fuel, with broken flaps.

hokkuk
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    And another follow-on question to that might be "How long will it take the FAA (or other applicable regulatory agency) to revoke the pilot's license after it's discovered that he or she took off with broken flaps?" – reirab Oct 28 '14 at 07:54
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Sure.

Whether the aircraft is still on the runway or already airborne when it reaches the airspeed necessary for sufficient lift without flaps is rather irrelevant.

Simon Richter
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The Fokker 70 and Fokker 100 take off with no flaps even on short runways.

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Flaps are a drag device. Airlines have toyed with the idea of no flap takeoffs for a while. You simply need higher airspeed for liftoff. It is completely safe with the correct speed....usually 3-15 knots faster depending on airframe.

user51991
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  • As highlighted by a comment in another answer, you should also consider tire limitations when asking for higher speed before liftoff. – Manu H Aug 16 '20 at 18:54
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You may be able to take off but as soon as you reach a height of 40-50 feet you lose wing in ground effect and will crash unless you have reached actual free air flying speed. Assuming a completely unobstructed route ahead of the runway the plane will eventually get enough airspeed to fly normally without flaps.

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  • Ground effect isn't an off and on thing. You gradually lose the benefits of ground effect with increasing distance to the ground. It doesn't just suddenly disappear. – user33651 Nov 27 '20 at 10:06
  • I think you will find that ground effect drops off exponentially with increasing height and is only 10% by the time a height of 90% of wing span is reached. The other factor is that the plane will stall very easily because of the high angle of attack normally involved in take-off and there is little height to play with to drop the nose back down. – Bryan Duggan Nov 28 '20 at 17:19