LED High demand
 

Hi

Can I ask why? There are only small little bits of metal moving? Is it the airflow around them that is the reason why they needs lots of energy to move?

Regards

Pin

Think of the aerodynamic forces. The stagnation point on the wing will always be somewhere on the LEDs and you are attempting to move them in the face of the full airflow at up to 250kts IAS in the case of the first stage of flap on many aircraft.

Think also in the case of Kruger flaps the amount of extra surface area you are attempting to present to the airflow. I know nothing of the dynamic change in aerodynamic forces as the wing shape changes but I would imagine it is quite impressive. I would also guess that in the case of slats, both the relative airflow and the flow acceleration in the gap would tend to try to close the gap.

Of course, the slats on the Rallye open themselves, as you slow down.

Suction instead of pressure on the Rallye...and Tiger Moth.

Jammie,
As I recall it, it was airflow pressure which held the Tiger slats closed against a light spring. As the airspeed washed off the spring overpowered the airflow and the slats extended.

And the NA Sabre and Sabreliner.

ZeBedie:Well, more precisely: As AOA and Cl increase, slats will open themselves, regardless of IAS.

On the Hun, the slats came out at 290 in 1G flight; at 6Gs it was probably around 420, never looked. But we always did a slat check before ACT, dive out to .420-450, pull 6Gs and ensured they deployed smoothly and symmetrically.

GF

And if maneuvering, as in a bit of roll in a turn or turbulence, the slats are assymetrical, each responding to that wing's workload. The wing is smarter than the pilot!

And the A-4. And the -262