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Joined: Tue Mar 29, 2005 10:48 am

MD-11 Hydraulics/Emergency Landing

Wed Mar 28, 2001 7:43 pm

I'm currently writing a novel in which the following sequence occurs:

The pilot of an MD-11 is confronted with an electrical fire on board. He loses one engine and has very little controllability and almost no ailerons. He's losing his hydraulics and can only turn right. Still, he manages to guide the plane in toward the runway.

When he's coming in for landing, he notes that the landing gear isn't down. He presses a button that provides manual control over the landing gear, but nothing happens. He checks his instruments and sees that he's almost out of hydraulic fluid. But then he realizes it's what may be holding back the landing gear. He takes a chance and "vents his remaining hydraulic fluid" and the landing gear comes out just in time.


1. Does the MD-11 have a "flashing red button" that provides manual control over the landing gear?

2. Is what I've described ("venting hydraulic fluid") an actual option for a MD-11 pilot whose landing gear isn't down? If not, how would he proceed in this emergency situation?

3. Are there any other questionable technical points in the sequence? (For instance, could an electrical fire on board spread and trigger these other problems?)

Thanks in advance for any help and/or alternative solutions you can provide!


RE: MD-11 Hydraulics/Emergency Landing

Wed Mar 28, 2001 10:35 pm


Why did you pick the MD11?

The answers to your questions are:
1: No
2: No
3: Yes.

Sorry for the short answers, but I'm outta time. Hopefully MD11nut will jump in here.

Posts: 384
Joined: Wed Apr 05, 2000 11:07 am

RE: MD-11 Hydraulics/Emergency Landing

Thu Mar 29, 2001 1:32 am

Why not use the gravity drop for the gears?? I'm not sure if Md-11s have this but don't most airliners do???

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Joined: Tue Oct 26, 1999 11:34 am

RE: MD-11 Hydraulics/Emergency Landing

Thu Mar 29, 2001 1:33 am

There is no airliner were there is automatic control over the landing gear. The red light you have probably heard about just indicates the gear is not down when the a/c is in a landing configuration below a certain altitude.

If the MD11 is like its predessor, the DC10 the a/c has 3 hydraulic systems. Each engine drives two pumps for 'its' hyd system plus the a/c has two electric pumps & reversable motor pumps to pressurise one system from another. Each flight control surface is powered by two hydraulic systems so looseing an engine will not effect cotrollability of the a/c.

No a/c has the ability to "vent hydraulics" it would be like you venting your blood !

Please let me know the name of this book, I will know to avoid it when is comes out.

RE: MD-11 Hydraulics/Emergency Landing

Thu Mar 29, 2001 5:16 am

I wasn't going to answer this thread but since Ambasaid asked, I might as well add my two cents. All of the posts here are great. To directly answer Edward's questions, please see Ambasaid's post. I'll try to expand his laconic replies a bit.

There is no flashing red button that provide manual control over the landing gear. If you had an electrical fire, chance is the flashing red button would not work anyway due to lack of electrical power. There is a manual lever (called alternate gear extension lever) to manually extend the nose and main landing gears in the MD-11. It is located ont the floor, on the right side of the pedestal. To manually extend the Center landing gear, you operate the "center gear alternate extension handle". It is located on the floor forward of the main circuit breaker panels. Both of these lever/handle once activated, bypass the hydraulics and allow the gears to free-fall (by their weights) and mechanically latched into position (You don't need any hydraulics).

2. Like VC-10 says, you don't vent hydraulic fluids.

3. Your scenario is highly unlikely. While anything is possible, it requires multiple failures and outrageous misfortunes to arrive at the scenario you described.

It is admirable that you tried to clarify with the forum. My recommendation would be that you do more research of the aircraft's systems before attempting to write it. Since Tom Clancy was able to do it on, at the time, a top secret submarine at libraries, you would have no problem finding out info on the MD-11. While it is understandable that the MD-11 is sensationalized in the public eye more than any other aircraft, I wish you hadn't picked it. Enough bad press had already befallen the aircraft and the public might be tired of it already. Pick something new or just keep it generic?

Best Regards,

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