Beldaran

Hello,

I would like to post a few questions regarding the Thrust Reverser of the MD-11. I am student in aerospace, but my knowledge of the thrust reverser operations is still very limited and I would like to learn more.

I read somewhere that the T/R has two settings, what is meant by this? Do they mean the two "normal" settings of a T/R: reverse idle and reverse at (max) 50% thrust? Or does the MD-11 have a different reverser setting capability? Which operating mode is "normal" or is this pilots discretion?

Is there a specific cut-off speed for the application of the T/R or is this totally at the discretion of the pilot? If so, what is common practice during a landing?

Is it likely that operating the thrust reverser below the cut-off speed results in FOD or is there a certain margin? If FOD is likely below the cut-off speed, are there any incidents on record of FOD by using the MD-11 thrust reverser?


Side question: what is the average runway length used during landing of a MD-11 (combined version)?

Hopefully anyone can help me with these questions.

Kind regards.

CE750

MD-11 TR's are like most, 100% variable based on how much you pull back on the levers. They max out usually around 98% N1, but that's a meaningless figure as it's going to vary with density alt as the FADEC will govern the N1.

By 80Kts you should be at TR idle, and by 60 TR's should be off.. there is a HIGH likelihood of FOD if you've got spooled up TR's below 60 kts..

As for landing distance.. the MD-11 has a HUGE weight spread.. You can land as heavy as 491,500 or as light as 300,000.. with autobrake in Max (rarely done), you can stop it at 491,500 at sea level in 5000'.

hope this helps

jsfBoat

talk about stol characteristics!

CE750

well, for a "Heavy" it does well, but it's no DASH-7..