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Guest tallpilot

Why no flaps?

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The link below shows an A300-600 taking off from Changi.http://www.flightlevel350.com/video_streaming.php?id=5713This is the first time I've seen a take-off where flaps haven't been used. The "canoes" are not even slightly dipped, infering there isn't even a small degree of flap.Interestingly, the roll-out also seemed very short, so.....I'm assuming either a very light plane, a very short trip, or maybe both.But no flaps being used? Didn't think it was an option..Looking forward to some words of wisdom.CheersTimNZWN

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many aircraft can operate without using flaps and regularly do.If the runway is long enough that you can generate enough speed to get lift without them, that may be preferable.

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Thanks for your response......But if flaps can be used to get you in to the air quicker, regardless of runway length, then wouldn't this be a preferred option from a safety perspective?I would have thought airlines would make this type of SOP mandatory, but I guess I'm wrong! ; )Tim

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I'm sure I'm the only flightsimmer with an almost paranoid irrational fear of flying?So, this would completely freak me out. I'd be thinking: wow, these pilots are asleep at the yoke and WE'RE ALL GONNA DIE.Bizarrely enough, all this simming has made me much more self-conscious about the whole airplane thing. Used to have no problems flying ratty airlines out of crappy airstrips, etc. Now, I'm basically frozen with panic at every clang and rattle and at the same time feel like I should be going up to the cockpit offering (idiotic) advice about flying. Weird. ricardo

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Could be there was a strong headwind. But don't mind me, I don't know much about airliner operations. I'm a GA guy. :)-Scott

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>many aircraft can operate without using flaps and regularly>do.>If the runway is long enough that you can generate enough>speed to get lift without them, that may be preferable.I have no real idea of the specifics, but considering it's a large heavy aircraft, flaps & leading edge devices would lower the takeoff speed, which in turn would save on tire wear, as well as getting weight off the tires sooner. Perhaps a leading edge device is in a takeoff position, and flaps are not required? I have no idea, and am quite curious. If someone has specifics of the operation of this plane, I'd be interested. Of course, smaller light weights never require flaps much of the time.L.Adamson

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The plane used slats, which are located on the leading edge of the wing. It is a high lift device. You are right, it was probably a light load.Marcus

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Flap schedules for A300/A310 are 15/00 or 15/15 for take offs I think, correct me if im wrong.Richard

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Assuming the LDS767 is "spot-on" in regards to realism on this issue, a warning message is given if no flaps are selected when applying full throttle.One also assumes that Boeing intends flaps to be used for ALL take-off's, hence the smack around the head with a wet fish if you forget.The assumption then follows that flaps are a non-negotiable requirement for a 767 take-off.Would one not assume then that if flaps for take-off were an essential bit of kit, and necessary for the process of flight, that Airbus would also have the same requirement?Assuming the above is true, why would a pilot choose to ignore the requirement?And this take-off is at Changi, and I don't think their runways are anything special length-wise.Hmmm...curiouser and curiouser.CheersTim

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I'm no expert but I belive that there is a small bit of flaps on the leading edge of the wing. Is it possible that these were extended but not the main flaps on the back of the wing?

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I think there's a couple of factors, that determine whther flaps get used or not. To start with, although it was mentioned that no flaps were used, it is possible that a small amount could have been used that just wasn't noticed. 5 degrees of flaps doesn't look like much. The leading edge slats are easy to miss too.But, ok, whether there was 5 degrees or 0, I think the original question remains valid. I'm sure that on some aircraft, when heavily loaded, that they might not be able to do this (someone mentioned the 767), but maybe on the A300, this isn't necessary.Also, someone mentioned that flaps generate drag, slowing acceleration, and the target speed is usually V2+10 (depending on aircraft type). If reduced flaps, or "no flaps" still permit an aircraft to takeoff on a given runway, then it might make sense to reduce the flap setting in order to achieve the target climp speed quicker. From a safety point of view, this might be more significant than reducing the amount of time the aircraft wheels are touching the runway.So, I guess if the extra speed will generate the same lift as a particular flap setting, then it is better to use the greater speed. So many variables here though - aircraft type/loading/runway length/altitude/runway condition/weather/etc...Ok, time for a real aviation type to chime in. :)- Martin

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Hi Tim,I've flown in several A300B4 aircraft as a pax. All were relatively short flights of 1-3 hours, and in all cases only leading edge slats were deployed. Maybe there was also a small trailing edge panel (similar to an inboard aeleron, but only used for lift and not for banking) that was also deployed. I think it's the type of aircraft. Interestingly, when these aircraft are parked the slats are down too.Bruce (about to make the big trip from the US to New Zealand, where I'm from :) ).

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yes, your takeoff speed goes down when using flaps, but the added drag means you need a bit more distance to reach that speed than you'd need to reach the same speed without flaps.You're also going to use a bit more fuel until you have retracted them, and of course induce a bit more wear and tear on the wing mechanism.There's almost certainly a sweet spot ;)It's the same with thrust reversers.You're using less runway, but using more fuel and causing more maintenance cost on those reversers.Some airlines tell their pilots to never use them for those reasons (except for emergencies of course).In fact one aircraft was lost in a landing accident because the airline had expressly prohibited the use of thrust reversers and the captain was more afraid of disciplinary action for breaking that ban than for a government investigation after a possible incident overrunning the runway...

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>make sense to reduce the flap setting in order to achieve the>target climp speed quicker.That's not true. Target speed for flaps will be much less than target speed for clean configuration.>So, I guess if the extra speed will generate the same lift as>a particular flap setting, then it is better to use the>greater speed. Again, not true. One of the limiting factors during takeoff is maximum tire speed. You can't increase ground speed as much as you want or tires will fail. I figure the only reason someone was taking off either with no flaps or with leading slats only was that the aircraft was practically empty and flps or no flaps made no big difference. A strong headwind would also help.Michael J.http://www.precisionmanuals.com/images/for...argo_hauler.gifhttp://sales.hifisim.com/pub-download/asv6-banner-beta.jpg

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