Reverse thrust on B744's

Why do the leading edge slats on B744’s retract when reverse thrust is used, is this an automatic response to reverse thrust?

where did you see this happen? … in/172651/ … in/253722/

Learn something new everyday.

I have seen it on lots of onboard videos.

I had been wondering about this for ages & finally decided to ask the question, thanx "misler " for your answer LOL :smiley:

Every plane is slightly different but… on most plane’s you can lift the flaps on landing to improve braking effectiveness (true on Cessna 152 and 747-400). Remember, flaps improve lift. Risk of FOD can be an issue on larger, faster aircraft too. On some aircraft these systems are automatically attached to a squat switch while on others its a part of procedure/ after landing check list. It doesn’t make sense to improve low speed lift while throwing out the spoilers and thrust reverses to stop the plane from flying and slow it down.

It is automated to the thrust reverse. It is done to reduce FOD damage to the slats from the reverse flow.

747 has Krueger flaps, not slats.

Great example of what the reversed thrust (therefore, FOD risk) looks like on a B744. Does it look like the outer Krueger flaps take the most abuse? (let alone engines 1 & 4)… Yet the outer ones don’t retract.

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