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#81
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![]() "Jack Davis" wrote in message news ![]() Steve, the difficulty only arises when people who know absolutely nothing about airline flying try to pass themselves off as experts. So what caused the difficulty this time? |
#82
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![]() "Geoffrey Barnes" wrote in message link.net... I'm guessing that the pressure differential at ground level isn't enough to prevent the exits from opening, but that this differential is (logically) much higher at altitude, and thus would prevent the exits from opening in flight. But I could be wrong. The pressure differential wouldn't have to be that great to create a considerable force holding the exit in place. I don't know what the surface area of an exit is, but a square twenty inches on a side has an area of 400 square inches. It would take 200 pounds of force to overcome a 1/2 psi pressure differential. |
#83
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On Thu, 08 Jan 2004 02:32:46 GMT, "Steven P. McNicoll"
wrote: It appears I've stumped you as well. Not quite. Here's a hint for you: When a Captain decides to evacuate the jet the crew completes the Evacuation check list. At the completion of that check list the engines and APU are shut down. Got it figured out yet? -J Jack Davis B-737 -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
#84
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On Thu, 08 Jan 2004 02:33:36 GMT, "Steven P. McNicoll"
wrote: "Jack Davis" wrote in message news ![]() Steve, the difficulty only arises when people who know absolutely nothing about airline flying try to pass themselves off as experts. So what caused the difficulty this time? You. -J Jack Davis B-737 -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
#85
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"Geoffrey Barnes" wrote
So, just how would the emergency exits get opened when the aircraft is on the ground and needs to be evacuated, if the cabin pressure is significantly higher than the outside pressure? I'm sure that every aircraft has some differences, but the Boeing B-707 and B-727 that I flew worked as follows: It is desireable to have "some" pressurization differential at takeoff for passenger comfort. This prevents the outflow valves from slamming shut at liftoff with the engines at takeoff thrust causing a discomforting pressure "bump". For obvious reasons, it is also desireable to have the cabin de-pressurize after landing. To accomplish these two goals, the pressurization controller has a switch labeled "takeoff" and "landing". Normally left in the "landing" position, the outflow valves are electrically driven open. Just before takeoff, the switch is placed in the "takeoff" position and the automatic features of the controller closes the valves somewhat to cause no more than a .125 psi differential. This pressure limit is an FAA aircraft certification limit and is sometimes stated as "no more than 250 ft below field elevation". The reason for the limit is obvious....to permit an emergency evacuation. Sometime during flight, the controller switch is placed in the landing mode and upon touchdown, the "squat switch" on the landing gear signals the controller to open the outflow valves. At a maximum of .125 psi differential, the air load on an average emergency exit would be less than 100 lbs. Bob Moore ATP B-707 B-727 PanAm (retired) |
#86
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In article k.net, "Steven
P. McNicoll" writes: Do the sky marshals guard every emergency exit? What would happen if a terrorist opened and emergency hatch at 36,000 ft? Can they be opened at all when the plane is at altitude? Well, if they can be opened at altitude, the terrorist would be the first to depart. So what would his purpose be in opening one? Not only that, but if he can open it at altitude, then he is Superman and you're going to lose anyway. Don -- Wm. Donald (Don) Tabor Jr., DDS PP-ASEL Chesapeake, VA - CPK, PVG |
#87
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![]() "Jack Davis" wrote in message ... Thanks for the tip - I'll try to remember that. No charge. Give your brain a chance, boy! That's good advice, you should heed it yourself. Suppose someone calls me on the interphone and says he's a FAM and starts feeding me some BS about a "situation"? How do I know for sure unless I've met him/her previously? How do you know what for sure? If the person on the phone is truly a marshal you have a "situation". If the person is posing as a marshal do you not also have a "situation"? Would I be willing to risk the lives of my passengers and crew on what could possibly be a diversion? How is the risk increased by not knowing if the caller is truly a marshal? How do I really know what's going on back there? You don't. Why would you need to? For all I know there could be six terrorists poised at the door and I could be wasting valuable time talking to some lying schmuck on the phone. Think about it and tell me how you would handle the situation. Schmuck or marshal makes no difference, if someone on the phone tells you there's a "situation" in the cabin then there's a "situation" in the cabin. Advise ATC that you have a "situation" and divert to the nearest suitable field. Don't open the cockpit door for anyone, let security forces on the ground sort out the "situation". And, in the unlikely event that an FA has to knock someone in the head with a fire extinguisher (present company comes to mind) because he/she feels that another 9-11 style attack is in the works, I'd be all kinds of ****ed-off if the FA accidentally clocked a FAM and Abdullah is now free to take over the jet! So what was the marshal doing that caused the FA to believe he was about to initiate another 9/11 style attack? |
#88
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![]() "Richard Riley" wrote in message ... If you're really interested I'll be happy to tell you. But it seems like you're just looking for an argument. So I'll end it here. Tell me. |
#89
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On Thu, 08 Jan 2004 18:06:33 GMT, "Steven P. McNicoll"
wrote: "Jack Davis" wrote in message . .. How do I really know what's going on back there? You don't. Why would you need to? Oh, I get it now. We'll talk again when you get some PIC time. Congratulations! You just made it to the Kill file along with the "Rockaway baby". (Is that you, Bill?) -J Jack Davis B-737 -----= Posted via Newsfeeds.Com, Uncensored Usenet News =----- http://www.newsfeeds.com - The #1 Newsgroup Service in the World! -----== Over 100,000 Newsgroups - 19 Different Servers! =----- |
#90
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![]() "Jack Davis" wrote in message ... Oh, I get it now. We'll talk again when you get some PIC time. Congratulations! You just made it to the Kill file along with the "Rockaway baby". (Is that you, Bill?) No doubt I join many others there who raised questions you could not answer. |
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