What is the purpose of the MD-11/DC-10 Tail Engine?

I did not know where to post it so Ia m going to post it here. So the engine that is one the tail of these planes, I cannot see any fan blades, so what is the purpose of this engine other than before ETOPS and how does it work.

I also found this.


so its like a APU?

Thats not an APU, its an actual engine that creates thrust. Clearly

Was not it.


I didn’t say it was the APU.

In my post, it says Without the APU.

Wait, are you kidding? I can’t figure out the tone 😂

This is about the most incorrect answer ive ever seen on a question in the IFC. A simple google search would’ve given you the correct answer

Here is a more in-depth answer provided by: https://www.quora.com/Why-does-a-McDonnell-Douglas-MD-11-have-an-engine-at-the-tail-fin-What-are-the-advantages-of-such-configuration-Also-what-is-the-advantage-of-a-non-symmetrical-winglet

"As already said by Robert, MD-11 is essentially a stretched DC-10 but…why did DC-10 had an engine in the tail? :-) I think there is a commercial reason that comes from the time when DC-10 started to fly.

At that moment, ETOPS planes (big twin planes allowed to cross Oceans) did not exist. DC-10 tried to fight commercially 4-engine planes by being allowed transoceanic flights with three engines. If you want to keep the symetry of a plane with an odd engines number, one of them has to be placed in the longitudinal axis.

When ETOPS planned were allowed, DC-10 and MD-11 lost the market battle, not only because an engine there could be problematic in an uncontained failure -as it happened in United-232- but they’ve got caught in the middle (more expensive than big twin planes and not so different from a 4-engine plane to justify the MD-11). Furthermore, DC-10 and MD-11 had a number of major accidents uncommon in other big planes."


My bad guys, sorry.

I thought the OP was talking at the opening at the very rear of the aircraft, not the engine itself.


At the time twin-engine aircraft couldn’t fly over the Atlantic or international, MD wanted a wide body aircraft with only two jet engines, but the rules said that it may not fly international so they made the trijet(hacking the system)As @mwe2187 said

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It was a way for airlines to get around the 60min twin jet ETOPS without using highly inefficient quadjets. This first came on the 727, then DC-10 then L1011 then MD-11. Of course there were a few European and Russian (at the time Soviet) manufacturers too.

They could fly International as long as there was a diversion point within 60 minutes of their location at all times.

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It was so that a medium size airliner could fly long haul before ETOPS, more eficant and smaller than the 747s and 707s

There are fan blades in there, they’re just a lot deeper.

oh I thought that but idk lol

and why did it crash so much?

It’s an old aircraft… That’s all I can say.

I know but even when it was new.

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Every new aircraft is a gamble. Look at the max. It takes a couple of crashes for all of the kinks to get worked out. Even then that’s sometimes not enough.

There were several issues with engines on it. If one failed, it was tough to operate with just two because of the balance. If either of the wing engines failed, they had a lot of trouble controlling the aircraft. and many of the engine issues with catastrophic