View Full Version : A300 Take-off flap setting

13th Mar 2002, 17:06
Having recently flown LHR-DOH-DXB on my holidays (with the route reversed on the way home), all sectors A306, my question is this:-. .. .Why on the long haul 'heavy' takeoffs were they conducted flapless (except for the slats and drooped aileron), while the short hop 'light' takeoffs used takeoff flap??. .. .As a Boeing driver, it seems odd as we always use flap 15 or 20 regardless.... .. . <img border="0" title="" alt="[Confused]" src="confused.gif" /> <img border="0" title="" alt="[Confused]" src="confused.gif" /> <img border="0" title="" alt="[Confused]" src="confused.gif" /> <img border="0" title="" alt="[Confused]" src="confused.gif" /> <img border="0" title="" alt="[Confused]" src="confused.gif" /> . .. .BN2A

13th Mar 2002, 18:05
BN2A As far as the A300-B4 is concerned if you use flap you become more weight limited since your climb gradient is reduced (single eng performance). Thus provided you have the field length available, you can get more weight off the runway using 0 flap than 8 flap or greater.On short sectors were weight is unlikely to be a problem 8 flap is often used to get off a 'lumpy' runway more quickly thus increasing pax comfort. I assume this technique also applies to the A300-600.. .Hope this helps. Cheers.

13th Mar 2002, 18:35
BN2A- Sadly, Boeing is quite far behind low speed optimization of their aircraft. All of the Boeing Commenrcial aircraft use outdated technology that somebody developed in the 50s. Airbus also optimizes their Vspeeds for optimal climb rate. Boeing lumbers off the runway as slow as they possibly can and meet FAR 25 requirements. <img border="0" title="" alt="[Big Grin]" src="biggrin.gif" /> <img border="0" title="" alt="[Roll Eyes]" src="rolleyes.gif" /> . .. .But that may soon change.....

16th Mar 2002, 08:43
BN2A,. .. .I'm interested in knowing which Boeing aircraft is restricted to 15 and 20 Flaps.. .. .Thanks. .. .Mutt.

16th Mar 2002, 13:17
Hi there,. .. .having flown the DOH-MUC route on Qatar Airways I can only suspect that it has to do with the unusually long runway available at Doha airport (something on the order of 15,000 ft if I remember correctly). At the time, it also took me by surprise taxying on the hammerhead for a northbound departure and not seeing any flap extension. Checking the acceleration time on a stopwatch delivered not too unusual takeoff-run values, though (only a little bit longer but definitely faster than usual upon rotation).. .By the way, there is an ideally located Hotel (Sheraton Doha) located right under the extended runway centerline, so if airplane noise is music to your ears, like it is to mine, then lying in its poolside garden is quite interesting because you can watch aircraft coming in on long final almost to before-touchdown crabbing in crosswind conditions.. .. .Cheers,

17th Mar 2002, 17:46
I remember flying Perth-Phuket a few years back on a A300. Me being the ever concious and paranoid back seat driver that I am I noticed that the flaps were still up for Takeoff. Being my first experience on Airbus instead of Boeing I was a little apprehensive during the take off roll. Reading crash mags about incorrect flap settings a few days before didn't help my cause.

17th Mar 2002, 18:45
Just to put an end to this, the A300-600 is approved for takeoff with the following slat/flap configurations:. .. .15/0. .15/15. .15/20. .. .Doha has one of the worlds longest runways, it therefore stands to reason that the takeoff would be done at 15/0, doing so will allow a greater takeoff weight, which will be translated into either payload or a thrust reduction.. .. .Mutt.

21st Mar 2002, 17:52
mutt,. .. .My company's procedures state flap 15 for takeoff, unless there is contamination when you use flap 20. This is for the 757.. .I don't have the Boeing manual to hand right now, so not sure whether it's a Boeing thing or a company thing.... . <img border="0" title="" alt="[Smile]" src="smile.gif" />

Willit Run
21st Mar 2002, 22:12
Here in the good ole US of A, we A-300 B4 operators use 0 flap,16 degrees of slat for take off, unless flaps 8 is required for T.O.i.e, short runway.. .While we were all sitting in GS for this plane, we thought it a bit odd that we were using no flaps for take off, but like all bus operators, we must trust the way Airbus thinks, and do the Airbus recomended thing, no matter how wierd it seems. This airplane is impressive with a full load and no flaps for take off. That would be a "good" impressive, as opposed to the "other" impressive.(scary)