Talk:Takeoff

message: This article only deals with fixed wing takeoffs. If it isn't limited in the tile it should cover all forms of flight including helicopters, birds,aircraft carrier takeoffs (steam catapult and skijump), V/STOL... balloons and carrier takeoffs are illustrated but not covered inthe text. Cyclopaedic 19:26, 28 April 2007 (UTC)
thread_title:  Limited to fixed-wing aircraft? 

message: When rotated, an aircraft will NOT "continue to rotate" unti it stalls.  Rotation is typically applied until the nose is at a specified position. Mike Stramba 16:43, 1 Nov 2003 (UTC)
replies: text: I know this is a very old discussion now - one I haven't come back to until now. Yes, there is lift, probably not enough to fully support the aircraft's weight at this stage however. But rotation is definitely about the wheel axle, not c.g. - if it were about the c.g. it would require that the wheels sank some distance into the concrete, which can't happen. Thus the aircraft nose is actually levered upwards by the lift force acting against the fulcrum of the main wheels. But yes, you're right that really it's a small point. Graham 22:31, 8 December 2005 (UTC)
thread_title:  Rotation 

message: :In cost controls a take-off is the action of counting and measuring from drawings or specifications key words: estimating, construction, building, civil engineering, architecture, engineering Ref: Jose R. Teres 26/Oct/2005 http://www.mikeholt.com/news/archive/html/master/electricalestimatingandpm4.htm
- Ste|vertigo 19:36, 8 December 2005 (UTC)
replies: text: removing reference to autorotation, as not relevant Cyclopaedic 19:26, 28 April 2007 (UTC)
thread_title:  Removed text 

message: article mentiones takeoff but also take-off . Is it takeoff, take off, or take-off? i need this for an article. thank you.
:Take off when a verb. Takeoff or take-off when a noun. Cyclopaedic 19:02, 28 April 2007 (UTC)
thread_title: take-off, take off, or takeoff

message: "The take off speed is directly proportional to the aircraft weight; the heavier the weight, the greater the speed needed."
this seems rather misleading and perhaps outright wrong. ive always been under the impression that take off speed is proportional to the effectiveness of the aircrafts wings, the effectiveness itself being determined by the wing surface area primarily, and also by left-generating devices, geometry, etc. this is why planes as varied as a 737 and a 747 and an antonov 124 all have comparable take off speeds, but a concorde has a much higher take off speed.
at best, this statement would need to be amended to say that take off speed is directly proportional to aircraft weight and inversely proportional to the effectivensss of its wings. but arguably, the wing configuration is the overwhelmingly important criterion. Downward machine 18:45, 24 December 2006 (UTC)
replies: text: For any given aircraft, the quote from the article is 100% true. Comparing unlike aircraft is not the intention of this statement, so perhaps it should be written more clearly ;)--chris.lawson 00:39, 26 December 2006 (UTC)

text: I think the term "directly proportional" is wrong in this case. Direct proportion is the kind of relation that is expressed as Y = aX. In this case when you multiply the value X with 2,you also multiply the value of Y with two. Now think about boeing 777 - 200 LR. When it performs a takeoff with no payload and just 10 tonnes of fuel, its weight would be 158121 kg. And if it performs a takeoff with MTOW, the wieght would be 347550 kg. The proportion between them is 2.198. The term "directly proportional" implies that the takeoff speed in the latter case will be 2.198 times as much as the takeoff speed in the former case. This doesn't seem to be quite possible. Gokaydince (talk) 16:41, 1 October 2008 (UTC)
replies: text: The phrase "directly proportional" is 100% false and Chris Lawson is 100% wrong, as Gokaydince correctly intuits. In fact, for a fixed-wing (non-Short TakeOff) plane, the lift must exceed the weight, and lift equals a constant (wing planform area), times the "wing effectiveness" (we call it lift coefficient), times the dynamic pressure, which equals one-half the air density times velocity squared. Thus the ratio of takeoff speeds at two conditions is roughly proportional to the square root of the weight ratio, which in Gokaydince's example would be 1.4826. ("Roughly" because there might be a difference in angle at liftoff, which changes the lift coefficient.) JustinTime55 (talk) 21:32, 25 July 2013 (UTC)
replies: text: The statement in the article is currently: For a given aircraft, the takeoff speed is usually dependant on the aircraft weight; the heavier the weight, the greater the speed needed. The only situation where takeoff speed is not dependent on weight is in a multi-engine aircraft when the weight is so low that the takeoff speed is equal to minimum control speed Vmc, or perhaps 110% of Vmc. (Vmc is not affected by aircraft weight.) Dolphin (t) 23:50, 25 July 2013 (UTC)
replies: text: Thanks for the clarification. The article doesn't seem to mention the minimum control speed. I was planning to put the lift equation in the article, and invert it to explain the square-root relationship to weight. We should then explain Vmc, and say something like "The takeoff speed can't be lower than the minimum control speed, therefore in some cases where the takeoff weight is sufficiently low, the takeoff speed becomes invariant with weight." I see the article V speeds mentions Vmc, and there are several versions of it, and it's dependent on the assumption of one engine out for multi-engine aircraft. (I assume it must still exist for single-engine aircraft?) JustinTime55 (talk) 15:57, 26 July 2013 (UTC)
replies: text: No, single-engine aircraft don't have a minimum control speed because there is no asymmetric thrust when that one engine fails. Centerline thrust aircraft like the Cessna 337 don't have a minimum control speed, even though they have more than one engine. Dolphin (t) 13:15, 31 July 2013 (UTC)
thread_title:  Take off speed versus weight 

message: I have heard that airplanes consume 50% of the fuel during take off. Is that a myth? Or is it real?
59.93.41.59 08:03, 26 April 2007 (UTC)
thread_title:  fuel consumption during take off 

message: Having four pictures of mid-sized Boeing and Airbus passenger jets taking off seems a bit excessive. Can we perhaps have some pictures of some smaller, non-military, planes taking off - maybe a microlight? 217.155.20.163 19:53, 5 June 2007 (UTC)
thread_title:  Pictures - too many?