Does not specifically affect the MD-11: Does it matter what RPM the engine has when engaging reverse thrust? I can imagine that when cutting throttles at 50' and below the time remaining until touchdown would be insufficient for the engines to spool down to ground idle, so when reversers get deployed the turbine would still be at a reasonable RPM...Andreas

Does not specifically affect the MD-11: Does it matter what RPM the engine has when engaging reverse thrust? I can imagine that when cutting throttles at 50' and below the time remaining until touchdown would be insufficient for the engines to spool down to ground idle, so when reversers get deployed the turbine would still be at a reasonable RPM...Andreas

It doesn't matter. The engines aren't actually reversing their direction of rotation, it's only the exhaust thrust that is being deflected forward so providing a braking effect. :( Iain Smith

The spoilers have to be deployed with the throttles at idle, the spool down is not the issue you might imagine... the time it takes to actuate the system is sufficent. It is not as though you were reversing engine rotation or shifting gears... the reverser is just a air flow diversion mechanism.

And as I understood the tutorial, you first unlock the reversers on T/D, the callout reverse thrust available comes, then you can engage reverse thrust...Or did I misunderstand this?Andrew

I'll ignore the flight/ground idle issue...There is a physical lock on the reverse levers that prevents them from being selected until the thrust levers are at the aft stop, so your thrust will be pretty close to idle. I'm not sure if there's an actual limit above which reverse will not engage though. I've never heard of that.