Any "Latest & Greatest" about Delta?
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I posted something similar in frustration about Alaska and some guy jumps on here with the overused, wornout, tiresome, moronic phrase "why dont you quit and go over to Alaska then". You should know by now, you arent allowed to say anything negative as your company shrinks, your competitor grows or is making more money than you. Don't try to push for change. Just suck it up or quit and go to the other company. Got it?
I posted something similar in frustration about Alaska and some guy jumps on here with the overused, wornout, tiresome, moronic phrase "why dont you quit and go over to Alaska then". You should know by now, you arent allowed to say anything negative as your company shrinks, your competitor grows or is making more money than you. Don't try to push for change. Just suck it up or quit and go to the other company. Got it?

Actually, I wish it were only 16.5 years. I expect to spend 22 years at DAL, never crack the 50% mark and never sit in the left seat (I don't intend to be an M88A in NYC on reserve just to make CA). Never saw C2K pay (furloughed), haven't cracked even a 100K (on 11th year 73n F/O pay). This next contract better be good - I've paid my dues (literally and figuratively). I hope Tim's definition of significant improvements is somewhere near my definition (I did fill out my survey).
I am a little puzzled as to why this LOT 767 aircraft ended up landing with the gear up. I am not second guessing the Captain, but I am confused as to what actually happened. I’ve posted the following on a few sites but I haven’t heard anything back.
“Reports have the cause as a center hydraulic system failure. If that was the only failure, then the landing gear should have been extended using the Alternate Gear Extension System. The 767 center hydraulic system has two independent AC electrical pumps, an air driven demand pump (ADP), and an emergency Ram Air Turbine (RAT) to power the center system components. The system also incorporates a standpipe in the hydraulic fluid reservoir at 17% to prevent a complete loss of fluid in the event of a component leak. Inoperative items with a complete loss of the center hydraulic system include center auto pilot (A/P), right A/P stab trim, some spoilers, ½ stab trim, NORMAL flap and gear operation, and auto speedbrake system. Alternate gear extension is fully functional unless this hydraulic failure is accompanied with or caused by a total electrical failure. With a total electrical failure including the depletion of all battery power, a specific hydraulic shuttle valve that is held open electrically will then close and not allow the gear or flaps to be lowered normally or even by using alternate extension methods. A total electrical failure is extremely remote, especially for the 767ER which has an additional hydraulically driven generator (HDG) electrical power source. An electrical failure is not mentioned as a cause, and certainly does not appear to be the case here because the flaps were down. Any single jammed gear or gear door would not prevent the other two from extending. If this less than desirable landing scenario was caused by the failure of the center hydraulic system, then I believe there must have been an electrical failure in the hydraulic shuttle valve as well. In other words, a dual system failure. As unlikely as that may be, it is possible I suppose. Any other 767 drivers have any ideas? Am I missing something? BTW: The 757 hydraulic systems were designed differently to avoid this scenario altogether.”
It makes me wonder if the crew overlooked something as simple as the alternate gear extension. Heros to dirtbags in 60 seconds. LOL I hope not. What say you.
“Reports have the cause as a center hydraulic system failure. If that was the only failure, then the landing gear should have been extended using the Alternate Gear Extension System. The 767 center hydraulic system has two independent AC electrical pumps, an air driven demand pump (ADP), and an emergency Ram Air Turbine (RAT) to power the center system components. The system also incorporates a standpipe in the hydraulic fluid reservoir at 17% to prevent a complete loss of fluid in the event of a component leak. Inoperative items with a complete loss of the center hydraulic system include center auto pilot (A/P), right A/P stab trim, some spoilers, ½ stab trim, NORMAL flap and gear operation, and auto speedbrake system. Alternate gear extension is fully functional unless this hydraulic failure is accompanied with or caused by a total electrical failure. With a total electrical failure including the depletion of all battery power, a specific hydraulic shuttle valve that is held open electrically will then close and not allow the gear or flaps to be lowered normally or even by using alternate extension methods. A total electrical failure is extremely remote, especially for the 767ER which has an additional hydraulically driven generator (HDG) electrical power source. An electrical failure is not mentioned as a cause, and certainly does not appear to be the case here because the flaps were down. Any single jammed gear or gear door would not prevent the other two from extending. If this less than desirable landing scenario was caused by the failure of the center hydraulic system, then I believe there must have been an electrical failure in the hydraulic shuttle valve as well. In other words, a dual system failure. As unlikely as that may be, it is possible I suppose. Any other 767 drivers have any ideas? Am I missing something? BTW: The 757 hydraulic systems were designed differently to avoid this scenario altogether.”
It makes me wonder if the crew overlooked something as simple as the alternate gear extension. Heros to dirtbags in 60 seconds. LOL I hope not. What say you.
Last edited by Waves; 11-02-2011 at 11:22 AM. Reason: Spacing
I hate to say it outloud, but I think they may have "screwed the pooch." Lets hope not for their sake. Other than a total electrical failure causing the shuttle valve to close, I cannot think of a logical single failure for their scenario. A ctr hyd system failure by itself just won't inhibit the landing gear extension.
I remember the shuttle valve with the gear uplock, but I didn't remember that was the case with the flaps.
The only thing I could think of was loss of the center system combined with the depletion of the battery (a la AA 757)... but if the shuttle valve had to do with the flaps as well, my theory is flawed.
The only thing I could think of was loss of the center system combined with the depletion of the battery (a la AA 757)... but if the shuttle valve had to do with the flaps as well, my theory is flawed.
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Better yet, put all your trips on the swap board and let someone else pull a 120hr. month...while you sit on the beach in FLL, watching the planes pass overhead, on their way to the next 7 hour, snow storm induced, ramp hold out in JFK!
You can watch me sail by too...look, over there to the left, that's me, flying...a hull!
You can watch me sail by too...look, over there to the left, that's me, flying...a hull!
Clamp,
Your theory is not flawed, I just didn't say it quite right. Quoting our training manual, "With the loss of both AC busses, flight beyond 30 minutes may result in complete loss of electrical power and the inability to extend the gear and flaps." The gear won't extend because of the closed shuttle valve and the flaps may not extend because of the loss of the center hydraulic system pumps and no electrical power to lower them with the alternate electrically driven system. Apparently the ADP isn't sufficient to power the flaps down by itself. From the pictures, it looks like all the flaps were down. From the reports I've read, they don't mention any electrical problems. Additionally, a catastophic electrical failure would certainly be cause for an immediate diversion. For these three reasons, I don't think they had an electrical problem, but if not, then why did they land gear up? If they did have one, then why didn't they mention it and why did they continue to destination? It doesn't make sense to me. If they had a system leak, I wonder where that fluid was going? Around some hot pumps perhaps. One thing they did have going for them if their aircraft was using Skydrol instead of Mil-H-5606. There are conditions under which Skydrol will burn, but Skydrol fluids are "fire resistant." Traditionally the term "fire resistant" has been used to describe phosphate esters, as opposed to mineral oil based hydraulic fluids, because they are very difficult to ignite at room temperature. In standardized testing, a fine mist spray of Skydrol cannot be ignited with an oxyacetylene torch. The same fine mist spray of a mineral oil hydraulic fluid, such as MIL-H-5606 or MIL-PRF-83282, produces a large fireball when touched by the torch. I nearly had to eject due to a hydraulic pump meltdown with MIL-H-5606.
P.S. Remember, the 757 doesn't have this problem. There should never be a scenario in the 757 in which all the gear fail to extend.
Your theory is not flawed, I just didn't say it quite right. Quoting our training manual, "With the loss of both AC busses, flight beyond 30 minutes may result in complete loss of electrical power and the inability to extend the gear and flaps." The gear won't extend because of the closed shuttle valve and the flaps may not extend because of the loss of the center hydraulic system pumps and no electrical power to lower them with the alternate electrically driven system. Apparently the ADP isn't sufficient to power the flaps down by itself. From the pictures, it looks like all the flaps were down. From the reports I've read, they don't mention any electrical problems. Additionally, a catastophic electrical failure would certainly be cause for an immediate diversion. For these three reasons, I don't think they had an electrical problem, but if not, then why did they land gear up? If they did have one, then why didn't they mention it and why did they continue to destination? It doesn't make sense to me. If they had a system leak, I wonder where that fluid was going? Around some hot pumps perhaps. One thing they did have going for them if their aircraft was using Skydrol instead of Mil-H-5606. There are conditions under which Skydrol will burn, but Skydrol fluids are "fire resistant." Traditionally the term "fire resistant" has been used to describe phosphate esters, as opposed to mineral oil based hydraulic fluids, because they are very difficult to ignite at room temperature. In standardized testing, a fine mist spray of Skydrol cannot be ignited with an oxyacetylene torch. The same fine mist spray of a mineral oil hydraulic fluid, such as MIL-H-5606 or MIL-PRF-83282, produces a large fireball when touched by the torch. I nearly had to eject due to a hydraulic pump meltdown with MIL-H-5606.
P.S. Remember, the 757 doesn't have this problem. There should never be a scenario in the 757 in which all the gear fail to extend.
Last edited by Waves; 11-02-2011 at 12:54 PM. Reason: Added Skydrol and 757
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