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3-2-1-Now

MD-11: Pilot Challenge: Total Hydraulic Failure

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Hi,Anyone want to give this a go?Conditions:* Loss of #2 engine* Loss of all hydraulics.Best regards,Robin.

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Man you really want the beta team killed off don't ya? :-)There is a special section in the manuals on the 'Sioux City' scenario, I must admit I've had other areas I am focussing on to date, but I will try it out sometime and report back.

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wow,Is manual reversion simulated? If so, the only thing missing would be the amount of force and strength you need to move the control column in pitch and roll. I tried this in the 737 NG sim where we turned off all 4 hydraulic pumps. You have to be way ahead of the aircraft in anticipating control inputs and you may occasionally need the PNF to back you up on the controls. Crashed going over the threshold as I made the cardinal error of trying to control direction with the rudder to align with the runway centerline ;-) I wonder if the MD-11 system is similar?Dinshaw.

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>> Man you really want the beta team killed off don't ya? :)haha! No, not at all! No beta, no aircraft! :DJust curious as to how the sim handles it. I know in RL, they tried this maneuver in the real sim, and they couldn't pull it off. One #### of a piece of flying from the pilots!!Best regards,Robin.

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After the Sioux city crash, MD installed a hydraulic shut off valve for Hydraulic system 3. If you have an explosion in engine number 2, hydraulic system 1 and 2 will be lost, but a valve will close if hydraulic quantity of system 3 is below 4,75 USG. So you will not lose system 3.

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NASA also tested succesfully a PCA (Propulsion Controlled Aircraft) system for the MD-11 (and th F-15) :)So in that case, if you lose all hydraulics (thus the flight controls) the system automatically transform the output of your yoke into power settings to turn, climb, descend... kinda like a Sioux City scenario piloted by a robotLink : http://www.dfrc.nasa.gov/Gallery/Photo/MD-...HTML/index.htmlDeniz

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PCA was actually done in a test on an MD-11 and the pilot landed safely, however, it was not a manual landing. It was completely computer controlled all the way to landing using only engine output. The FAA decided there were not enough incidents where the hydraulics would all fail so they scrapped the idea.An Airbus crew had the same thing happen in Iraq when they were shot with a SAM and it hit the wing and took out all hydraulic pipes running through the wing. They used only thrust control to turn, climb and descend. Where did the crew of JAL123 fail where the crews of these other aircraft succeed???Makes you wonder how many people have to die before they do something about it.And also, the Sioux City landing was a DC-10. But I guess it was the same principle.You Tube has amazing videos on this.Goran

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>PCA was actually done in a test on an MD-11 and the pilot>landed safely, however, it was not a manual landing. It was>completely computer controlled all the way to landing using>only engine output. The FAA decided there were not enough>incidents where the hydraulics would all fail so they scrapped>the idea.>An Airbus crew had the same thing happen in Iraq when they>were shot with a SAM and it hit the wing and took out all>hydraulic pipes running through the wing. They used only>thrust control to turn, climb and descend. >Where did the crew of JAL123 fail where the crews of these>other aircraft succeed???>Makes you wonder how many people have to die before they do>something about it.>And also, the Sioux City landing was a DC-10. But I guess it>was the same principle.>You Tube has amazing videos on this.>Goran>Hi Goran,If my memory is correct, JAL123 suffered too much damage on the tail section after a decompression. Investigation revealed that a repair (on the tail after a tailstrike) had not been carried out as it should have been. The crew lost hydraulics, but managed to heep the plane flying for a while using throttles. They did a great job, but if the tail (rudder/stabilo's) is too damaged, there is nothing you can do.The poor guy who felt responsible for this repair committed suicide.Wijnand (EHBK)

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That repair was carried out on the bulkhead. Being that closes the pressure vessel, its very specific to the repair type. Interestingly enough, it was Boeing who did the repair.Allan

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I can't imagine any company involved with a repair of this magnitude, wouldn't send a Quality Control Inspector from Boeing HQ to oversee the work being done before it being OK'd to fly.I don't know the procedures, but wouldn't it have to be OK'd and then OK'd again by someone a few levels higher than the local Japanese engineers??Goran

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Well, thats probably why they sent Boeing in to do it. Their field repair team is something to behold actually. They bring EVERYTHING they need to do a repair, and do it quickly. But something like a bulkhead repair, thats definately out of the realm of any airlines normal maintenance. Also, I forgot to mention, that Boeing did a mod to al 747-100s and -200s to install a panel where the tail meets the fuselage, closing out that little tunnel. This was to prevent the tail blowing out on a failure of the aft pressure bulkhead, as in JAL123.Allan

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>Well, thats probably why they sent Boeing in to do it. Their>field repair team is something to behold actually. They bring>EVERYTHING they need to do a repair, and do it quickly. But>something like a bulkhead repair, thats definately out of the>realm of any airlines normal maintenance. Also, I forgot to>mention, that Boeing did a mod to al 747-100s and -200s to>install a panel where the tail meets the fuselage, closing out>that little tunnel. This was to prevent the tail blowing out>on a failure of the aft pressure bulkhead, as in JAL123.>>AllanWhat is normal airline maintenance?I have some very good friends within aircraft engineering - and they complete all sorts of work that it outside the scope of the Structural Repair Manual. Their airline has an in-house technical department that design repairs and require Boeing approval. Boeing constantly revise repair standards, and sometimes previous repairs need to be redone

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Hi Steven,By normal maintenance I mean things that some airline's wont/cant do for themselves. Obviously, some airlines are more equipped than others to do different things. This includes repairs to major structural assemblies, i.e., pressure bulkheads, vertical stabilizer mounts. I am an aircraft maintenance technician for a major freight company, and previously worked in passenger airlines as well as other cargo only carriers, so I can see where you are coming from. Going outside of the SRM for patches and the like is one thing, but bulkhead repairs are another. Heres a perfect example. Atlas Air (a former employer of mine) B742 with a drill bit lodged in the aft pressure bulkhead after takeoff:http://atlasmergerfacts.com/img/pic00292.jpghttp://atlasmergerfacts.com/img/pic12382.jpghttp://atlasmergerfacts.com/img/pic17421.jpghttp://atlasmergerfacts.com/img/pic19718.jpghttp://atlasmergerfacts.com/img/pic18716.jpgNot even Boeing would attempt a repair there, and unfortunately, this aircraft is now written off. I hope this sheds some light on the subject.Allan

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