A359 Takeoff flaps

The approximate speed for which flaps 1 should be extended in the a350 is at 255kts and the maximum speed below 10,000ft is 255kts meaning that you would have to fly with flaps 1 extended all the way up to 10,000ft. I have watched a few YouTube videos and the slats are retracted fairly early. Definitely below 10k ft! Can anyone explain this for me?

Thanks, Jacob 👍🏻

Ive only used the A350 twice but I used 1+F on takeoff (May be too much but I don’t know) and retracting them at 235-245 knots works fine

Flap speeds do not have any correlation with speed limits below 10,000ft. I personally will takeoff with Flaps 2. After I gain sufficient airspeed to reduce flaps, I will do so. Flaps 1 only extends the leading slats. By the time I hit 240kts, my flaps are at Flaps 0

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Basically. In a lot of Airbus aircraft they use different types of speeds. For example ‘green dot speed and S speed. This is calculated by the in flight technology and you may use infinite FMC to calculate these for you. When approaching, you need to extend flaps 1 when you pass green dot. On the other hand, when taking off you retract to flap 0 at S speed, which is usually considerably lower than greens dot. Note that flaps aren’t always engaged/retracted at the same speed in every flight. Extension schedules vary depending on weight and weather conditions. 255 is not the approximate speed as the speed always Changes. Usually your S and Green dot speed will both be below 250 knots.

Check out:
https://www.infinitefmc.com/

According to the A359 flight operations manual I’ve been using, there is no requirement for the use of slats (flaps setting 1) up to 10,000ft – it simply recommends that these are used for holding and/or approach, and that flaps settings 1 + F could be used for takeoff.

Your usage of flaps and slats during your flight will mainly be dependent on your weight – hence why the flight manual I use specifies three possible flap configurations for takeoff (flaps 1+F, flaps 2, or flaps 3).

Here’s my guide to A359 flap usage from my manual I’ve been citing:

Lever Position Flap Configuration Flight Phase
0 Clean Cruise
1 1 (Slats Only) Hold/Approach
1 1 + F Takeoff/Approach
2 2 Takeoff/Approach
3 3 Takeoff
3 3 + S Approach/Landing
Full Full Landing

My flaps usage usually depends on the weight of my aircraft, and I’ll usually work out what settings I’ll use before I depart, depending on weight and what speeds I’ll be flying at before I depart – but I don’t think I’ll ever find myself in a situation where I’ll need to be using slats up to FL100 at 255KIAS – that seems unlikely!

Hope this helps.

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How do you work out your different clean/flap speeds etc.
IFFMC only currently accommodates e190 and 320

Yes but maximum flaps speeds don’t Tell you when you need to deploy flaps. They only show the limit

You deploy them once yo need more lift (when the nose rises too much above the (artificial) horizon and you get a too high nose up attitude you will either increase speed or deploy flaps.

There’s no set speed as your vertical speed and may other factors are to be considered.

Usually just via intuition and experience in flying the aircraft – I do not usually formally calculate my Flap Retraction/V-Speeds. (Mainly due to time constraints on wanting to get airborne.)

I simply take into account any speed restrictions I may be required to follow as per my SID, take into account my aircraft weight, and then come up with points and speeds at which I’ll retract my flaps in line with my departure plan and certain fixes along it.

IF-Assistant does have a handy tool for calling out V-2 speed based upon your weight. I’d recommend taking a look if you’re not already using it!

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Yes but the weight controls the time at which the aircraft starts to list. There ARE set speeds. It’s not just a question of feeling

@Jacob_Laurie I’m not real sure you can watch some tutorials on YouTube of a A350 add on to a pc sim, (you can dm for more info about that) but I have no idea and that’d be my best recommendation

I get what you mean. Not sure though. Probably watch the LH A350 to Haneda video on YouTube to see if they have any set/special speeds?

They do. The speeds are calculated depending on approach/departure weight. I can verify with my pilot friend now for you

Really unsure to be honest. Didn’t think there would be set/calculated speeds for deploying the flaps (just Minimum Clean Speed and approach speeds), but as I said I am getting a bit unsure here.

If you have any details fell free to send me a PM.

Flaps on “Full” messes me up too much. I get that what you posted is what you’ve been reading/citing is your preferences, but still.

If you’re light or fast, then flaps on full for landing probably isn’t necessary, that’s true – I’m simply just citing what is recommended as per Airbus’ manual. This is why Flaps 3 or Flaps Full is recommended for landing.

It doesn’t matter too much if you’ve got a nice long runway to land on – you’ll just have a higher approach speed, longer landing distance and probably a slightly smoother landing. It is of course a matter of preference, if you’ve got the runway length to play around with. Happy landings!

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@JulianB I can confirm that the electrical flight instrument system (EFIS) shows the minimum clean speeds (flap extension/retraction) which are calculated dependent on weight.

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I like flaps set to 1. I just adjust my throttle in small increments (usually ~5%) to make sure i don’t crash.

Yes, that’s for Flap 1. I am unsure what’s about the other settings (I now believe there might be set speeds at some airlines, but unsure how this is calculated/wether this varies or not).

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I’m working on a temporary post that you guys can use when wanting to know flaps settings and takeoff/landing speeds for given aircraft loads.

Included will be some speeds that you should approach and flare at. It should hold you guys over until a Takeoff/Landing tutorial is published.

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