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Both Airbuses have similar flap deployment based on some YouTube videos I have watched, just wondering if they both have the same flap design being "Single-Slotted Fowler Flaps".

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enter image description here
Image shows spoiler droop. Source: Delta A350 Landing - Detroit Metro (YouTube)

Airbus calls the A350 flaps Adaptive Dropped Hinge Flap (ADHF). It's single-slotted, and Fowler motion is achieved by a deep pivot point, and the resulting gap is managed by spoiler droop, the latter increases the wing camber. (Spoiler droop is also used by the Boeing 787.)

If Fowler motion is desired, the hinge will be much more below the wing. A compromise is to choose a deeper hinge position and to control the resulting large gap with means like a spoiler actuation [...] On the A350 XWB the spoiler actuation is modified to let the spoilers not only deploy as primary flight control device upwards, but also down to 12° to follow the flap when it’s deployed on its hinge.[ref]

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Source: ref

The increased wing camber provides additional lift in the linear range (desirable for long fuselages). The drawback is shallower lift slope in the upper non-linear range, but that can be recovered by using bigger flap angles thanks to the spoiler droop, which delays the flow separation (more gradual transition).

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Source: ref


Reference:

  • Strüber, Henning. "The aerodynamic design of the A350 XWB-900 high lift system." 29th international congress of the aeronautical sciences. 2014. (PDF; icas.org)
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