Do large RC airliners like the huge Emirates RC A380 still need all the same control surfaces that a real A380 has I,e leading edge slats? If not why is this the case.

Many thanks for your time in advance Lee

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    $\begingroup$ Consider an edit-- a leading-edge slat is arguably not a control surface. $\endgroup$ Jan 10, 2023 at 12:33
  • $\begingroup$ Also the term you want is probably l.e. flaps not slats-- $\endgroup$ Jan 10, 2023 at 12:38
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    $\begingroup$ Related : aviation.stackexchange.com/questions/35723/… $\endgroup$ Jan 10, 2023 at 12:49
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    $\begingroup$ @quietflyer Slats (and other high-lift devices) are sometimes grouped under secondary control surfaces (e.g. SKYbrary says "Secondary flight controls are intended to improve the aircraft performance characteristics or to relieve excessive control loading, and consist of high lift devices such as slats and flaps as well as flight spoilers and trim systems."). $\endgroup$
    – Bianfable
    Jan 10, 2023 at 12:51
  • $\begingroup$ @Bianfable -- good point $\endgroup$ Jan 10, 2023 at 12:52

1 Answer 1


I've seen several r.c. airliners first-hand and none had leading-edge flaps. It's a matter of scaling. Kinetic energy scales according to velocity squared and these r.c. planes don't land at the same velocity as their full-scale counterparts, so stopping distance is less of an issue and the need to slow down the touch-down speed a bit more vanishes.

Same reason that the r.c. versions usually also dispense with wheel brakes, thrust reversing (some actually do have this, the electric ducted fans are simply run in the reverse direction), elaborate Fowler flaps (simpler hinged flaps serve instead), etc.

There are also Reynold's number effects to consider, but we really don't need to get into that to understand why features such as operating leading-edge flaps are usually omitted from r.c. model airliners.

In any oddball cases where the pursuit for scale accuracy is carried so far as to include features such as leading-edge flaps, it is clearly not a matter of a need for such features!

Here's a related ASE link-- Why do model aircraft fly and maneuver so differently from real aircraft?

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    $\begingroup$ I've noticed that certain features in an RC model may not be required aerodynamically, but the designer/builder includes them for realism. I'm amazed at the level of detail that some of these people achieve. $\endgroup$
    – jwh20
    Jan 10, 2023 at 12:36
  • $\begingroup$ KE = 1/2 mv^2, but v is linear in m, so that's why KE varies with v^3 not v^2? $\endgroup$ Jan 10, 2023 at 17:19
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    $\begingroup$ @CamilleGoudeseune -- I didn't realize until reading your comment that I had typed "cubed" instead of "squared", was simply an error-- $\endgroup$ Jan 11, 2023 at 12:59

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