Moonlight Graham Posted November 5, 2015 Report Posted November 5, 2015 Didn't see this topic up yet. This story is very fascinating, because the propaganda coming from the US and UK vs Russia and Egypt is coming out fast and furious so each side can spin the story to their political advantage. The US and UK and some of the US corporate media are eager to blame ISIS on the attack, which will obviously help the US's case that the West needs to destroy ISIS militarily and further show the need for the recent ground troops sent into Syria. On the other side, Russia and Egypt deny any evidence thus far that ISIS downed the plane. This is key for Russia, because If ISIS is responsible it will further anger the Russian people who will partly blame Putin's government for the deaths of hundreds of Russians aboard that plane since the attack would very likely have been retribution for Russia's increasing military involvement in the Syrian civil war. What are your thoughts on the happenings so far? What do you think happened to the plane? Do you trust what has been said by the US and UK so far? "All generalizations are false, including this one." - Mark Twain Partisanship is a disease of the intellect.
Wilber Posted November 5, 2015 Report Posted November 5, 2015 (edited) Depends on whether you accept the ISIS video as genuine. My first thought when I saw it was it definitely looked like an explosion. If you accept the assertion ISIS doesn't have a missile system capable of reaching that altitude (which I do and there was no sign of a missile track anyway), the remaining possibilities are a bomb or fuel tank explosion. A fuel tank explosion wouldn't account for the tail coming down so far away from the rest of the aircraft. On edit: There has never been an incidence of a fuel tank explosion on the A320 series aircraft. Edited November 5, 2015 by Wilber "Never trust a man who has not a single redeeming vice". WSC
Derek 2.0 Posted November 6, 2015 Report Posted November 6, 2015 Depends on whether you accept the ISIS video as genuine. My first thought when I saw it was it definitely looked like an explosion. If you accept the assertion ISIS doesn't have a missile system capable of reaching that altitude (which I do and there was no sign of a missile track anyway), the remaining possibilities are a bomb or fuel tank explosion. A fuel tank explosion wouldn't account for the tail coming down so far away from the rest of the aircraft. On edit: There has never been an incidence of a fuel tank explosion on the A320 series aircraft. But a fuel line leak and escaping vapors into a confined space, followed by a spark could.......
Wilber Posted November 6, 2015 Report Posted November 6, 2015 But a fuel line leak and escaping vapors into a confined space, followed by a spark could....... Anything is possible but the A 320 series has been in service since 1988 and there have been over 6500 built. Such a thing has never happened to one of them. Jet fuel is more like summer diesel, evaporates much more slowly than gasoline and less likely to be ignited by a spark. "Never trust a man who has not a single redeeming vice". WSC
Derek 2.0 Posted November 6, 2015 Report Posted November 6, 2015 Anything is possible but the A 320 series has been in service since 1988 and there have been over 6500 built. Such a thing has never happened to one of them. Jet fuel is more like summer diesel, evaporates much more slowly than gasoline and less likely to be ignited by a spark. Right, but fuel vapor has caused airliners to explode in the past..
Wilber Posted November 6, 2015 Report Posted November 6, 2015 Right, but fuel vapor has caused airliners to explode in the past.. True but I'm just going on what I think is most likely. All the A321's fuel is contained in the wing and center section between the spars. From the look of the impact area it looks like the wing came down as a single unit while the tail section was some distance away. "Never trust a man who has not a single redeeming vice". WSC
Derek 2.0 Posted November 6, 2015 Report Posted November 6, 2015 True but I'm just going on what I think is most likely. All the A321's fuel is contained in the wing and center section between the spars. From the look of the impact area it looks like the wing came down as a single unit while the tail section was some distance away. Fair enough, but fuel is fed to the APU in the tail section.....
Wilber Posted November 6, 2015 Report Posted November 6, 2015 Fair enough, but fuel is fed to the APU in the tail section..... The APU isn't normaly run in flight unless an engine driven generator is inoperative or an engine is shut down. We would have to know more about the mechanical condition of this aircraft and the airline's operating procedures. The fuel line to the APU might be pressurized depending on the location of the shutoff valve and whether it uses its own pump or one of the aircraft's fuel boost pumps, which would have been running. Don't know. "Never trust a man who has not a single redeeming vice". WSC
Derek 2.0 Posted November 6, 2015 Report Posted November 6, 2015 The APU isn't normaly run in flight unless an engine driven generator is inoperative or an engine is shut down. We would have to know more about the mechanical condition of this aircraft and the airline's operating procedures. The fuel line to the APU might be pressurized depending on the location of the shutoff valve and whether it uses its own pump or one of the aircraft's fuel boost pumps, which would have been running. Don't know. Right, but then there would still be fuel in the lines, just not pressurized (if said line was shut down).......like you said, we just don't know.
Wilber Posted November 6, 2015 Report Posted November 6, 2015 Right, but then there would still be fuel in the lines, just not pressurized (if said line was shut down).......like you said, we just don't know. Then why wasn't the leak more obvious on the ground where the APU was running and the line pressurized? Of course we don't know but the OP's question was whether we trust what the UK and US have said. I don't know about "trust" but based on the very limited amount of information we have seen, their version seems most likely to me at this time. "Never trust a man who has not a single redeeming vice". WSC
Moonlight Graham Posted November 6, 2015 Author Report Posted November 6, 2015 I think it's more likely a bomb than a fuel leak, given recent events. "All generalizations are false, including this one." - Mark Twain Partisanship is a disease of the intellect.
Derek 2.0 Posted November 6, 2015 Report Posted November 6, 2015 Then why wasn't the leak more obvious on the ground where the APU was running and the line pressurized? Who knows? A change in atmospheric pressure caused a weak pipe to fail?
Wilber Posted November 6, 2015 Report Posted November 6, 2015 (edited) Who knows? A change in atmospheric pressure caused a weak pipe to fail?The where line to the APU travels through the pressurized section of the aircraft it is doubled, a line within a line so if the inner line ruptures the fuel is contained by the outer line. A leak would have to occure between the tank where it enters the pressurized section in the main gear wheel well or after it leaves and enters the APU compartment. The outer lines in the pressurized area are supposed to be checked for the presence of fuel periodically.So, possible but unlikely. Edited November 6, 2015 by Wilber "Never trust a man who has not a single redeeming vice". WSC
Derek 2.0 Posted November 6, 2015 Report Posted November 6, 2015 The where line to the APU travels through the pressurized section of the aircraft it is doubled, a line within a line so if the inner line ruptures the fuel is contained by the outer line. A leak would have to occure between the tank where it enters the pressurized section in the main gear wheel well or after it leaves and enters the APU compartment. The outer lines in the pressurized area are supposed to be checked for the presence of fuel periodically. So, possible but unlikely. IIRC, one of the widows of the flightcrew suggested the airline was negligent in performing routine maintenance and that the Russian transportation authority is combing through their maintenance logs.
Wilber Posted November 6, 2015 Report Posted November 6, 2015 IIRC, one of the widows of the flightcrew suggested the airline was negligent in performing routine maintenance and that the Russian transportation authority is combing through their maintenance logs. That is a wildcard in this deal. "Never trust a man who has not a single redeeming vice". WSC
On Guard for Thee Posted November 6, 2015 Report Posted November 6, 2015 Who knows? A change in atmospheric pressure caused a weak pipe to fail? That would have to be one hell of a pressure change. Plus as has been pointed out the line wouldn't likely be pressurized at altitude unless there was some other problem A modest change in ambient pressure isn't going to cause an unpressurized line to fail.
Guest Posted November 6, 2015 Report Posted November 6, 2015 Who knows? A change in atmospheric pressure caused a weak pipe to fail? A change in atmospheric pressure probably caused a detonator to go off.
Derek 2.0 Posted November 6, 2015 Report Posted November 6, 2015 That would have to be one hell of a pressure change. Plus as has been pointed out the line wouldn't likely be pressurized at altitude unless there was some other problem A modest change in ambient pressure isn't going to cause an unpressurized line to fail. Well yeah it would, at sea level atmospheric pressure is 14.7 psi, at ~31000' it drops to ~3.8 psi, a decrease of ~75% (hardly "modest"). And the line would be pressurized, just static (if a valve was closed in the system), if no longer being pumped. So yeah, drastic increase and decreases in pressure do effect fuel lines.... The question remains, where does the aft pressure bulkhead start in the tail section of the A320 and did it remain with the fuselage or the tail section after the crash?
On Guard for Thee Posted November 6, 2015 Report Posted November 6, 2015 Well yeah it would, at sea level atmospheric pressure is 14.7 psi, at ~31000' it drops to ~3.8 psi, a decrease of ~75% (hardly "modest"). And the line would be pressurized, just static (if a valve was closed in the system), if no longer being pumped. So yeah, drastic increase and decreases in pressure do effect fuel lines.... The question remains, where does the aft pressure bulkhead start in the tail section of the A320 and did it remain with the fuselage or the tail section after the crash?
Derek 2.0 Posted November 6, 2015 Report Posted November 6, 2015 A change in atmospheric pressure probably caused a detonator to go off. It could have.......I know most modern airports have barometric triggering systems that passenger luggage goes through prior to entering the aircraft, but that's not to say ISIS didn't have a plant in the airport staff with a workaround.
On Guard for Thee Posted November 6, 2015 Report Posted November 6, 2015 (edited) Well yeah it would, at sea level atmospheric pressure is 14.7 psi, at ~31000' it drops to ~3.8 psi, a decrease of ~75% (hardly "modest"). And the line would be pressurized, just static (if a valve was closed in the system), if no longer being pumped. So yeah, drastic increase and decreases in pressure do effect fuel lines.... The question remains, where does the aft pressure bulkhead start in the tail section of the A320 and did it remain with the fuselage or the tail section after the crash? Yes I am quite aware of the rate of pressure change with altitude, but it still wouldn't affect a non pressurized line all that much. When the pump is turned off as the APU is no longer needed, the pressure drops. If you look at the crash pics it's clear to see the portion of the tail that sits there broke off fwd. of the aft bulkhead. The bomb idea seems to be more prevalent with that observation, however I'm sure analysis will show up residue of some sort if it was in fact a bomb. Edited November 6, 2015 by On Guard for Thee
Derek 2.0 Posted November 6, 2015 Report Posted November 6, 2015 That is a wildcard in this deal. Here's one source that states the aircraft had a previous tail strike......bets on how long until the airline executives, on down, are counting trees in Siberia?
Derek 2.0 Posted November 6, 2015 Report Posted November 6, 2015 Yes I am quite aware of the rate of pressure change with altitude, but it still wouldn't affect a non pressurized line all that much. When the pump is turned off as the APU is no longer needed, the pressure drops. Then why would you suggest a ~75% drop in atmospheric pressure as modest? And no, the pressure wouldn't drop, fore if it did, outside the creation of a vapor lock in the lines and bubbles in the fuel system, the outside atmospheric pressure would pinch and distort a non-pressurized line considerably, every time the aircraft was flown until it failed.
On Guard for Thee Posted November 6, 2015 Report Posted November 6, 2015 Then why would you suggest a ~75% drop in atmospheric pressure as modest? And no, the pressure wouldn't drop, fore if it did, outside the creation of a vapor lock in the lines and bubbles in the fuel system, the outside atmospheric pressure would pinch and distort a non-pressurized line considerably, every time the aircraft was flown until it failed. Pressure lines are built to withstand a hell of a lot more pressure changes in a heartbeat than the difference between SL (sea level) and say, 35,000 ft. And yes pressure does drop off when the pump is turned off in those type of systems because it is no longer needed. Certain systems may require pressure to remain and then accumulators are installed. If you would need to APU again in flight, you would create fuel pressure to it by turning the pump back on.
Derek 2.0 Posted November 6, 2015 Report Posted November 6, 2015 And yes pressure does drop off when the pump is turned off in those type of systems because it is no longer needed. Well first, if static pressure drops off in the fuel system, in any fuel injected internal combustion engine, there is a leak somewhere in the fuel system..... Certain systems may require pressure to remain and then accumulators are installed. If you would need to APU again in flight, you would create fuel pressure to it by turning the pump back on. Second, the APU on the Airbus A320, draws fuel from the left/port fuel manifold, using the tank pump pressure to feed it in normal use, well having it's own specific pump for in-flight emergencies..........so you are wrong on both counts. -------- Your obvious errors aside, I'll await the official investigation results.
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