Malaysian Airlines MH370 contact lost
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W&F,
You and others promoting the silly "shadowing" idea need to learn about formation. If SQ was minding its own business cruising at M.84 ish and our hero, unaware of SQ's take-off time were 12 minutes off, it would take 1800nm to catch up using Mmo on MH370's T7. You can only "make up" 24 nautical miles an hour, that's the speed differential between normal cruise and Mmo on the T7.
You and others promoting the silly "shadowing" idea need to learn about formation. If SQ was minding its own business cruising at M.84 ish and our hero, unaware of SQ's take-off time were 12 minutes off, it would take 1800nm to catch up using Mmo on MH370's T7. You can only "make up" 24 nautical miles an hour, that's the speed differential between normal cruise and Mmo on the T7.
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Speaking of facts and questions...
CNN's Richard Quest (to whom I tweeted a question on this) just said on TV that his understanding "from US officials" is that when ACARS "reported in" at 1:07, it communicated to ground the "next 2 waypoints"...
...one of which is presumably this "pre-programmed left turn" AWAY FROM BEIJING
If this is Flight Plan A (A for Active) why is KL ATC not saying,
what? huh? where are u going? come again???
CNN's Richard Quest (to whom I tweeted a question on this) just said on TV that his understanding "from US officials" is that when ACARS "reported in" at 1:07, it communicated to ground the "next 2 waypoints"...
...one of which is presumably this "pre-programmed left turn" AWAY FROM BEIJING
If this is Flight Plan A (A for Active) why is KL ATC not saying,
what? huh? where are u going? come again???
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Suction feed of fuel on RR engines
This quote from Flown-It at post 5871 five pages back, at 18th Mar 2014, 21:50
My buddy flies the 2ER and emailed me the fuel management system manual; I'll try to wade through it and figure it out for you. Just in general: the system is set up with (roughly) 26,000 gal in the center tank and 9,300 gal in each wing tank. Center has two fuel pumps, one for each engine, and each feed line tees into the line from the wing tank on that side. The center pumps are at a higher output pressure than the wing pumps, so with both center and wing pumps working all feed is from the center tank. If center pump is shut off and wing either fails or is shut off, then suction, but only from the wing tank apparently (at least, as far as I have deciphered). The entrained air in the fuel has been known to restrict power output and cause reverse flows through the compressor when the pump(s) are off, until all the air in the fuel is gone, so the drill is to run with all the pumps churning away, at least until center is reduced or empty.
From that I draw that after the fuel gets cold and the entrained air is finally gone, it should siphon just fine. At that point, likely not altitude dependent (although that is my surmise, and not from the manual).
Lots been said about total electrical failure.
The Rollers on my plane are certified to my 51,000 ceiling BUT RR only guarantees them to suction feed to 20,000.
So what ceiling will the Rollers suction to on the T7? If closer to my 20K then MH370 could never have flown for the 7 plus hours. Thus total electrical failure seems unlikely.
Answers from T7 drivers please.
The Rollers on my plane are certified to my 51,000 ceiling BUT RR only guarantees them to suction feed to 20,000.
So what ceiling will the Rollers suction to on the T7? If closer to my 20K then MH370 could never have flown for the 7 plus hours. Thus total electrical failure seems unlikely.
Answers from T7 drivers please.
From that I draw that after the fuel gets cold and the entrained air is finally gone, it should siphon just fine. At that point, likely not altitude dependent (although that is my surmise, and not from the manual).
Last edited by OldDutchGuy; 19th Mar 2014 at 02:51. Reason: add original post data line (top)
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merlin driver:
Yes, excellent points concerning SAR, thank you, I am aware. However the objective at that point in my little exercise was to determine which was the greater of two possibilities; aircraft/aircraft system failure or hijack. If aircraft/aircraft system failure I assigned a high probability that the crash would be within a reasonable distance of last known position and 10 days of high coverage SAR in this space under this scenario should turn up some wreckage, it did not. Thus, all I am saying is that this fact makes the probability of a hijack greater than that of aircraft failure
Yes, excellent points concerning SAR, thank you, I am aware. However the objective at that point in my little exercise was to determine which was the greater of two possibilities; aircraft/aircraft system failure or hijack. If aircraft/aircraft system failure I assigned a high probability that the crash would be within a reasonable distance of last known position and 10 days of high coverage SAR in this space under this scenario should turn up some wreckage, it did not. Thus, all I am saying is that this fact makes the probability of a hijack greater than that of aircraft failure
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keeping SATCOM up makes perfect sense
@Ornis
@D.S.
Here is why network links are kept up. Suppose you have a scenario generating LOTS of ACARS messages in succession (e.g. AF447). If each message has to set up and tear down the link there is tremendous overhead added. Just setting up and tearing down a connection involves the exchange of a bunch of messages. When networks are designed a lot of attention is given to the most efficient use of resources to meet the design objectives of the network. We can rest assured that the keepalive ping is actually very efficient use of the sat link.
Just think how handy it is to have a SAT link up, whether you need it or not, all for the low, low cost of 1 ping each hour!
By the way, the computer you are reading this on is sending periodic keepalive messages so it can keep using the network address it currently has been assigned (assuming you are using DHCP and not a static IP address). It wants to avoid the extra headache of having its address expire and being forced to renew it. This is a very, very common practice in networking.
@D.S.
Here is why network links are kept up. Suppose you have a scenario generating LOTS of ACARS messages in succession (e.g. AF447). If each message has to set up and tear down the link there is tremendous overhead added. Just setting up and tearing down a connection involves the exchange of a bunch of messages. When networks are designed a lot of attention is given to the most efficient use of resources to meet the design objectives of the network. We can rest assured that the keepalive ping is actually very efficient use of the sat link.
Just think how handy it is to have a SAT link up, whether you need it or not, all for the low, low cost of 1 ping each hour!
By the way, the computer you are reading this on is sending periodic keepalive messages so it can keep using the network address it currently has been assigned (assuming you are using DHCP and not a static IP address). It wants to avoid the extra headache of having its address expire and being forced to renew it. This is a very, very common practice in networking.
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Useable Fuel?
I'm not aware of the fuel setup on the 777, but assuming it's like others I do know, is this possible, either on its own or in combination with other circumstances?
In aircraft I do know about, this is a possible scenario that came too close, far too close, to happening.
A) Aircraft takes of with fuel in both wing tanks and centre tank with all boost pumps on.
B) Due centre pumps having higher pressure they override the wing tank pumps and both engines feed from the centre tank.
C) Once all the fuel is used from the centre tank the wing tank pumps automatically take over as they have higher pressure then the now empty centre tank pumps.
D) Aircraft I am familiar with can suction feed from the wing tanks but not the centre tank.
Is it possible that the aircraft took off with the centre tank pumps not turned on?
Result, Everything is normal until the wing tanks run out of fuel at which time the engines EGT rapidly drops and due no engine-generator, electrics to power the centre tank pumps they don't work and as the aircraft cannot suction feed from the centre tank altitude is rapidly lost until such time as the aircraft makes contact with the ground after running out of fuel with the centre tank still full?
In aircraft I do know about, this is a possible scenario that came too close, far too close, to happening.
A) Aircraft takes of with fuel in both wing tanks and centre tank with all boost pumps on.
B) Due centre pumps having higher pressure they override the wing tank pumps and both engines feed from the centre tank.
C) Once all the fuel is used from the centre tank the wing tank pumps automatically take over as they have higher pressure then the now empty centre tank pumps.
D) Aircraft I am familiar with can suction feed from the wing tanks but not the centre tank.
Is it possible that the aircraft took off with the centre tank pumps not turned on?
Result, Everything is normal until the wing tanks run out of fuel at which time the engines EGT rapidly drops and due no engine-generator, electrics to power the centre tank pumps they don't work and as the aircraft cannot suction feed from the centre tank altitude is rapidly lost until such time as the aircraft makes contact with the ground after running out of fuel with the centre tank still full?
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If one were to tail another aircraft's radar shadow not only one needs military pilot skills especially when flying in the night (when one can possibly only see the tail lights or wingtip lights only) but also have the communications systems in "ON" mode to receive updates on exact flight path of the aircraft ahead. Given that all such equipment were switched off - this seems too unlikely.
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Put it in your flight planner from where it went missing then was sighted (if it was sighted ) in Maldives from where it was last known and you end up DIRECT LINE TO Somalia.
Why did the US Navy ships stop looking and go West with 7th fleet.
Why did the US Navy ships stop looking and go West with 7th fleet.
CNN's Richard Quest (to whom I tweeted a question on this) just said on TV that his understanding "from US officials" is that when ACARS "reported in" at 1:07, it communicated to ground the "next 2 waypoints"...
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aviation watcher,
Why do you assume that? Do you have much formation time, especially over long routes? I've flown across the Atlantic without the foggiest notion of the navigation, just when I needed to refuel.
GF
If one were to tail another aircraft's radar shadow not only one needs military pilot skills especially when flying in the night (when one can possibly only see the tail lights or wingtip lights only) but also have the communications systems in "ON" mode to receive updates on exact flight path of the aircraft ahead. Given that all such equipment were switched off - this seems too unlikely.
GF
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Interesting inteview on the Hannity show with General McInerny. He retired as Vice Chief or Staff of the Air Force and appears to have significant intelligence connections. A week ago he was saying don't ignore Pakistan. He was back on tonight making the case stronger. Some of the information he mentioned was that he believed the aircraft was in the Taliban controlled areas of Paksitan (Western?) where there were 3 airfields capable of handling the plane. He said that he beielved both pilots were complicit and that they did NOT turn off their communications (VHF, HF,SATCOM) and that US 'vacuum cleaners' would be expected to pick up their communications with their destination. He believed that the pressure will build on Pakistan and things will come to a head in 24-28 hours.
He also said that the US Navy would not have pulled its ships from the Indian Ocean unless they knew something. Also, Israel has gone on a higher state of alert, somenting they would not have done without intelligence.
He is, by far, the most believeable individual commenting on the situation.
http://foxnewsinsider.com/2014/03/18...anded-pakistan
He also said that the US Navy would not have pulled its ships from the Indian Ocean unless they knew something. Also, Israel has gone on a higher state of alert, somenting they would not have done without intelligence.
He is, by far, the most believeable individual commenting on the situation.
http://foxnewsinsider.com/2014/03/18...anded-pakistan
Last edited by PlatinumFlyer; 19th Mar 2014 at 03:48. Reason: Edited to add link
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Quote:
Put it in your flight planner from where it went missing then was sighted (if it was sighted ) in Maldives from where it was last known and you end up DIRECT LINE TO Somalia.
Why did the US Navy ships stop looking and go West with 7th fleet.
Because at the time it was supposedly sighted in the Maldives it was 8hr 45 after it left KL, a trip entirely over water and would have long before run out of fuel and buried itself in the ocean
Put it in your flight planner from where it went missing then was sighted (if it was sighted ) in Maldives from where it was last known and you end up DIRECT LINE TO Somalia.
Why did the US Navy ships stop looking and go West with 7th fleet.
Because at the time it was supposedly sighted in the Maldives it was 8hr 45 after it left KL, a trip entirely over water and would have long before run out of fuel and buried itself in the ocean
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If one were to tail another aircraft's radar shadow not only one needs military pilot skills especially when flying in the night (when one can possibly only see the tail lights or wingtip lights only) but also have the communications systems in "ON" mode to receive updates on exact flight path of the aircraft ahead. Given that all such equipment were switched off - this seems too unlikely
I think we all agree (and hope) the authorities have more information than has been publicly released.
I wonder if the Inmarsat satellites are really the information the authorities are going on. It certainly does sound plausible. However it does seem an odd coincidence that the claimed level of precision should just happen to produce a result of 40 degrees.
It also took a few days for this information to come out. While this delay does make sense, it also makes sense if there was a need to develop a plausible explanation in order to protect true capabilities.
The US has likely invested heavily in the area of tracking airliners - especially post 9/11 when primary radar was unable to track large jets flying around 2 of the most important US cities. They also have plenty of experience tracking phones - and have spent many years delivering "air mail" on the basis of real time phone intercepts.
We will likely never know. But it is possible the search is not quite the needle in the haystack that it appears. Hope so anyway.
I wonder if the Inmarsat satellites are really the information the authorities are going on. It certainly does sound plausible. However it does seem an odd coincidence that the claimed level of precision should just happen to produce a result of 40 degrees.
It also took a few days for this information to come out. While this delay does make sense, it also makes sense if there was a need to develop a plausible explanation in order to protect true capabilities.
The US has likely invested heavily in the area of tracking airliners - especially post 9/11 when primary radar was unable to track large jets flying around 2 of the most important US cities. They also have plenty of experience tracking phones - and have spent many years delivering "air mail" on the basis of real time phone intercepts.
We will likely never know. But it is possible the search is not quite the needle in the haystack that it appears. Hope so anyway.
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Put it in your flight planner from where it went missing then was sighted (if it was sighted ) in Maldives from where it was last known and you end up DIRECT LINE TO Somalia.
Why did the US Navy ships stop looking and go West with 7th fleet.
Why did the US Navy ships stop looking and go West with 7th fleet.
Apart from which, if it were only as far west as the Maldives, 7 hours after it went missing, then it must have been going very slowly (~250 knots), and probably would not have had enough fuel to make it much further west, anyway.
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Presumably whomever was in control would have entered a waypoint into the autopilot to take it to the southern Indian Ocean. Wouldn't setting it to 90°S be the simplest? The eastern of the two tracks devised by the NTSB is close to a direct track toward the South Pole.
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Back tracking NTSB positions
The graphic below is using an equidistant projection, and has a 40° and derived satellite elevation arcs drawn on it from backtracking the data provided by AMSA / NTSB. The red tracks represent the two speeds used by the NTSB and an assumption is made that the aircraft passed well to the west of Aceh, North Sumatra, to avoid PSR detection.
All times shown are UTC, commencing with the LKP at IGARI (1720z) and a possible PSR position at 1822z, all interconnected by an orange track to intercept the possible backtracked position west of Aceh.
The east track has been overlaid with light blue and hourly positions placed on it using a GS of 470 KTS.
Earth-SAT elevation angles are shown for the estimated arcs.
As the projection used is Equidistant, the tracks appear to be diverging to the west. If stretched in a polar direction, i.e. Mercator projection, those tracks should form a straight line and cross all Lat/Long at constant angles. However, if a way-point a large distance away has been entered into the FMS, the aircraft will be following a great circle path and a curved track on a Mercator projection is what one would expect.
All times shown are UTC, commencing with the LKP at IGARI (1720z) and a possible PSR position at 1822z, all interconnected by an orange track to intercept the possible backtracked position west of Aceh.
The east track has been overlaid with light blue and hourly positions placed on it using a GS of 470 KTS.
Earth-SAT elevation angles are shown for the estimated arcs.
As the projection used is Equidistant, the tracks appear to be diverging to the west. If stretched in a polar direction, i.e. Mercator projection, those tracks should form a straight line and cross all Lat/Long at constant angles. However, if a way-point a large distance away has been entered into the FMS, the aircraft will be following a great circle path and a curved track on a Mercator projection is what one would expect.
Last edited by mm43; 23rd Mar 2014 at 02:42. Reason: added Earth-SAT elevations.
