Here’s a link to the report broadcast today on Australian 60 Minutes about the search for MH370. Part 1:
Part 2:
Discussion after the jump…
The main thrust of the piece is that an independent air-crash expert, Larry Vance, has looked at photographs of the Réunion flaperon and decided that their relatively intact state, and the lack of debris from inside the aircraft, means that the plane must not have impacted the water at high speed, as would be expected if the plane ran out of fuel as a “ghost ship” and spiralled into the water. He interprets the jagged trailing edge of the flaperon as evidence that it was deployed at the moment of impact and was worn away when it struck the water.
I find it discomfiting when people say that the mystery of MH370 is not mystery at all–that they are absolutely confident they know the answer. Vance undercuts his credibility, I feel, by taking this stance. There is indeed a strong argument to be made that the plane must have been under conscious control to the very end; to me the most compelling is simply that the plane has not been found in the current seabed search zone. However it is less clear that someone attempted a ditching. What the show does not mention is that debris from inside the aircraft has indeed been found, suggesting that the fuselage could not have survived the impact and sunk to the bottom of the ocean intact. Indeed, the program doesn’t mention the other debris at all, with the exception of the Pemba flap, which is the other relatively intact large piece. The fact that most of the debris found so far is rather small is to me indicative of a higher-energy impact. But I have no strong opinion one way or the other; I feel that proper experts must look at the debris close up to determine what forces caused it to come apart.
The program cites the recently revealed flight-sim data from Zaharie’s computer as further evidence that the plane was deliberately piloted to fuel exhaustion and beyond. For the first time, the program showed on screen pages from the confidential Malaysian report. The producers of the show reached out to me as they were putting the program together, and asked me to comment on some of the data they had accumulated. Here are the pages of the document that they showed on-screen:
It’s worth noting that these pages offer a summary of the recovered flight-sim data which are described in greater detail and accuracy elsewhere in the confidential Malaysian documents. Here is a table showing a subset of what the documents contain:
Note that the numbering systems for the two data tables do not match. (Please do not ask me to explain this.) I suggest that for the purposes of discussion, the point saved at Kuala Lumpur International Airport be called point 1; the three points recorded as the flight-sim moved up the Malacca Strait to the Andaman Islands be called 2, 3, and 4; and the points over the southern Indian Ocean with fuel at zero be called points 5 and 6.
In order to understand the fuel load numbers in the second table, I made some calculations based on the fuel loads in a real 777-200ER. I don’t know how closely these match those in the flight simulator Zaharie was using. If anyone can shed light I’d be happy to hear it.
Worth noting, I think, is that the fuel difference between point 4 and point 5 is enough for more than 10 hours of flight under normal cruise conditions. The difference between these points is 3,400 nautical miles, for an average groundspeed of less than 340 knots. This is peculiar. Perhaps the flight-sim fuel burn rate is very inaccurate; perhaps the simulated route between the points was not a great circle, as shown in the second page of the report above, but indirect; perhaps Zaharie was fascinated by the idea of flying slowly; or perhaps points 5 & 6 come from a different simulated flight than 1 through 4. Readers’ thoughts welcome.
Also note that neither the locations nor the headings of points 1-4 lie exactly on a straight line from 1 to 4, which suggest perhaps that the route was hand-flown.
@Nederland
Liking your work. To de-energize the SDU, you have to manually isolate the LH AC bus, or alternatively, as I suggested earlier, you could possibly switch to backup generator, to force load shedding of non essential items, SATCOM included. To switch to backup generator, you would have to switch out both main IDG generators, and keep the APU switched out.
@Littlefoot @ROB @David
The SAT-phone call at 23:13 was unanwsered but acknowledged by the SDU.
So power on the SDU was still on, at that time.
Maybe the pilot decided to isolate the left IDG electric again after this event to not be distracted emotionaly further by phone calls. Or the call reminded him the SDU was still on power after he put it on line again at 18:25 and forgot to isolate it again after that. So he did this again after the 23:13 call.
I think it is still important to investigate the possibility of right engine flame out on the 7th arc and a left IDG main bus isolation that triggered the APU to start and consequently the 0:19 log-on.
In that case the plane could have flown another ~120 miles under power of its left engine.
I read IDG electrical isolation can be easily done in the cockpit as also the IFE switch off.
Back up generators will not power the SDU but when the APU kicks in the SDU will get power again triggering a log-on request:
http://ads-b.ca/777/B777-Electrical.pdf
Ge Rijn
The phone call at 23:13 was unanswered, but acknowledged by the SDU, but so was the 18:40 phone call.
The ACARS interrogation of 18:03, did not receive a acknowledgement from the SDU, which means the SDU must have been de-energized at the time.
From the above we can deduce that the SDU was (deliberately, I believe) de-energized some time between 17:07 and 18:03. It’s not possible to pin down the time any closer that that, but it was probable de-energized at about the same time the transponder was switched off. The SDU was re-energized at 18:24, prompting the 18:25 log-on. The SDU remained powered up for most of the remainder of the flight, up until a point sometime between 00:11 and 00:18. All one can say for certain is that it was de-energized after 00:11, and re-energized at 00:18.
ACARS was deliberately de-activated some time between 17:07 and 17:37, and remained off for the rest of the flight.
No disrespect intended, but you appear to be searching for a complex and convoluted explanation, when a much simpler one exists. What’s the problem with a simple solution? Occam’s Razor can be your friend, so why not embrace it?
@Johan
I was serious. I have not heard that suggestion previously.
@ROB: “ACARS was deliberately de-activated some time between 17:07 and 17:37, and remained off for the rest of the flight.” It was off at 18:25. If the SDU was unpowered at 17:37, ACARS would not have been able to communicate. Is there more information than that?
@Gysbreght
I’m thinking that after sometime after 17:07:48.907 the ACARS may have been turned off because of this a handshake request (1hr) would have been just after 18:07, but didn’t happen because MAS tried to get ACARS info (5 requests) at 18:03:41 after ATC contacted (where’s your plane) them at 18:02. If the sat comm had never came on at 18:25 and 18:28 then the next handshake because of the 18:03 (5 requests) activity would have been just after 19:04. Then MAS make at call at 18:39 (unanswered) which would make the next handshake request be 19:41 then no other interrupting requests. 20:41 then 21:41 22:41. Then a call at 23:13 would reset the send out request again due for approx an hour later that did happen 00:10:59. Then sat comm comes back on 00:1929 for a partial handshake. Then 00:1937.
[Post deleted by JW. It was a piece of misinformation propogated by supertroll Sy Gunson.]
@ Joseph Coleman: I’m not sure what you are trying to say. Perhaps it is better to make sense of the communications that did take place and not inject communications that did not.
@Gysbreght
You are splitting hairs again. I said the SDU was de-energized sometime between 17:07 and 18:03, but probably at the same time as the transponder was switched off. Of course it had to be on for the 17:07 ACARS transmission itself.
@ROB
How are you so sure the SDU was de-energized after 00:11?
I know this is the current hypothesis of the second engine flame out occuring a ~minute or so before 0:19 forcing the APU to start and triggering that log-on request.
I question this hypothesis, for a de-energizing of the SDU happened once allready before 18:03 most probably deliberatly induced by a pilot.
And re-energizing the SDU also happened before at 18:25 most also most probably by human intervention.
That’s why I suggest this events could have been repeated by human intervention.
Why not?
A de-energizing again of the SDU after 23:13 and a re-energizing of the SDU after the first (right) engine flame out at ~0:18 due to a left engine IDG electric isolation triggering the APU to start and triggering the log-on. With the plane flying for another ~15 minutes on its left engine beyond the &TH arc.
De-energizing of the SDU was done before so why would it not be possible to do it again manualy after 23:13?
And I don’t mean making things more complicated but to look for other possibilities that could have brought the plane outside the current search area.
IMO if it not gets found here every possibility (and maybe even former impossibilities) can be worth re-evaluating.
@Boris Tabaksplatt
What is statet in your post is not all correct IMO.
The back up generators do not supply power to the SDU. Batteries also won’t power the SDU according to this information:
http://ads-b.ca/777/B777-Electrical.pdf
@DennisW:
Thanks, then. I hope. I have not a chance right now to try to figure out what is factual about the reboot, or what corner of the plain it had to be executed from (but I know this has been discussed).
Or which competences that would have demanded.
But (with a little inspiration from Aaron I think), there is still, to me, the question whether the reboot and / or powerout could have been a message in itself. Either by a culprit or a passenger/crew member (locked out of cockpit or locked in/trapped in cockpit). And/or if it is by this or other circumstance should be viewed as directly connected to the FMT. (For one thing, if a pilot or culprit is busy with sorting out technical or other matters, and figure he will be that for a while, he may not want to give away his final turn / or, for that matter, fly by autopilot blackedout over Indonesia before he knows for sure he can turn unnoticed (or similar). And if he wants the triumph of people realizing that he is still in the air (and not gone down in SCS or hardlanded somewhere), he will want to send an anonymous but unmistaken message that he is in the air and heading somewhere (draw out a line towards Europe and check if the fuel takes him to Istanbul or Jerusalem or Burj Khalifa. this is after all after 9/11; and thus our culprit would have the time to go and disappear without a trace, as he must have believed).
If he could believe that something he did would be picked up and place him on a NW heading from KL.
This if the reboot is interpreted as a signal.
Do you have any thoughts yourself?
@ROB said:
@Middleton
@David
‘If he (the pilot) had simply switched them off by switching off the IFE/Seat power switch, he would also have disabled the video surveillance system, as this is also powered through the IFE switch. He needed to be able to monitor what was going on the other side of the cockpit door, while the depressurization was taking effect.’
If switching off the IFE also removes power to the video camera, how can you turn off power to the IFE (in whatever way) without also de-powering the video camera?
Also, why, once manually locked in the cockpit, would a hijacker need the cockpit door video surveillance system?
There’s a spyhole in the door if needed, which would give a better view of business class (and perhaps down the aisle into economy also) than a camera pointed downward just outside the cockpit door would, and after 40 minutes or so there would be no need.
Note very good vids, and for a 737 but likely similar, see 2.10 onwards – 3 cameras on the ceiling:
https://www.youtube.com/watch?v=tvWmzGvHP5I
And also – an idea of the field of view:
https://www.youtube.com/watch?v=L7v9ZtwA5_w
Here’s the 737 doors. Deadlock is top left – the circular knob with the two red dots:
https://forum.flightgear.org/viewtopic.php?t=24450&p=222431
The question is what items/systems would remain unpowered once the left bus and tie had been disabled. In the intentional scenario, once that is known it might provide more insight into what happened.
But it was likely not necessary to de-power the SDU in order to go dark (unless the cabin crew had satphone).
@Middleton
Maybe this is of help?
It tells what will not be power if both IDG’s or off by the back up system:
Backup AC Electrical System
The backup electrical system is designed to automatically provide power to
selected airplane systems.
The backup electrical system
automatically powers one
or both transfer busses when:
• only one main AC generator (includes APU) is available
• power to one or both of the main AC busses is lost
• approach (APP) mode is selected for autoland
• the system is automatically tested after engine starts.
The system transfers power without interruption.
Backup Generators
Backup power is provided by one variable speed, variable frequency generator
mounted on each engine. A frequency converter converts the generator frequency
to a constant 400 Hz. Only one backup
generator can power the converter at a
time.
Each backup generator contains two perm
anent magnet generators (PMGs) that
supply power to the flight control DC electrical system (refer to DC Electrical
System).
If both IDGs and the APU generator are
inoperative, a backup generator powers
essential airplane equipment. To re
duce electrical loading on the backup
generator, the following systems are inoperative:
•TCAS
•SATCOM
• Right HF radio
[HF Datalink installed]
• Right HF radio and associated datalink
• Center tank override/jettison pumps (center tank fuel is unusable and
cannot be jettisoned)
[777-200LR]
• Center tank override/jettison pumps (center tank and auxiliary fuel is
unusable and cannot be jettisoned)
• Position and other exterior lights (except nose gear landing lights)
• All non-essential cabin equipment (ga
lleys, entertainment systems, etc.)
• Passenger cabin lighting (except ni
ght, galley and cross-aisle lights)
• Cabin temperature control (remains
operative, but in degraded m
@all,
As to the disenabling of the SDU and it’s comeback at 18:25 UTC – no matter how it was done – I like the idea that it had to do with communication. Trying to prevent satphone calls by passengers from the phones in business class is certainly a very sensible guess. But maybe the SDU got re-enabled for the same purpose: the perp in the cockpit would’ve been certainly keen to know if someone tried to call him, who it was, and how often. That would be information he might’ve been very interested in.
I think it would be a great mistake to underestimate our perp now that some of us gave up the idea of a spoof 😉 . The hijack was still pretty sophisticated and meticulously planned in advance. Why shouldn’t the perp have tried to find out everything about such an important piece of equippment as the SDU? He could well have learned what it does, how to disable it and how to re-instate it. A perp who plans to go dark with his plane would certainly try to find out as much as he could about a piece of equippment designed for communication.
He would also try to find out what exactly happens if he starts to pull AC buses. Victor’s suggestion, that the perp might’ve pulled the left bus in order to stop the voice recorder from recording the ensuing mayhem after he locked himself in, might still have happened of course. But the comeback of the SDU might not be an indication for such an action. But what it might indicate is this: around 18:25 it was safe to re-enable the SDU because no one could make satphone calls anymore: the passengers and crew members were dead by then.
@Middleton @littlefoot
Maybe another reason to re-energize the left main AC bus again at 18:25 could be the following in the list posted above:
-Center tank override/jettison pumps (center tank fuel is unusable and cannot be jettisoned)
He would need all his fuel to reach so far into the SIO.
From the same source something on the IFE.
If switched off ALL components of the IFE are switched off. So if it was switched off before 0:19 I can imagine there would be no IFE log-on:
Cabin Systems and Utility Power
[IFE/PASS SEATS and CABIN/UTILITY switches basic with C/L 350]
Electrical power to various
cabin and utility systems can
be controlled from the
flight deck.
IFE and Passenger Seats
The IFE/PASS SEATS Power switch contro
ls power to the IFE and passenger
seats. Pushing the switch OFF removes power from the following:
• IFE (all components)
• passenger seats (including seat mo
tor power, personal computer power
outlets, and telephones)
@Ge Rijn,
If Nederland is right, then we have no indication whatsoever that the left AC bus has ever been pulled. It might’ve happened – but we can’t know for sure.
The only thing we know is that some ACARS messages didn’t go through which is a hint that at that time the SDU wasn’t working. And then we have the log-on request at 18:25 UTC which tells us that the SDU started functioning again.
We just assumed lately that this might’ve been an accidental by-product because someone pulled the left AC bus. We thought that this would be the simplest form of action because we assumed that ordinarily the flight crew and pilots don’t know how to de-activate and then re-instate the SDU deliberately.
But if Nederland is right it can’t have happened that way. The SDU’s comeback must’ve been produced by another chain of actions. And we should really contemplate that the disabling and the comeback of the SDU wasn’t just a by-product but the deliberate attempt to prevent communication through the satphones. And the comeback was also deliberately engineered because the perp might’ve been interested to know if someone would attempt to call the cockpit.
I think that is not an unreasonable scenario. The left bus might still have been disabled – maybe in order to stop the voice recorder – but there’s no indication that this really happened.
@ROB: Well, give or take 45 minutes doesn’t really matter, I suppose.
@Ge Rijn
As if per the suggestion of Rob the sdu was de-energized by switching to back up generator, the only available autopilot was the third with limited functionality (?), so another reason to re-energize could be to have the more advanced autopilot functions available? The centre tank was not needed straight away at 18:25, the advanced auto pilot might have?
Not to sure about this, just suggesting..
@littlefoot – Perhaps the perp wanted to re-pressurize the cabin/flight deck so he could remove his uncortable oxygen mask?
@Ge Rijn said:
‘@Middleton
Maybe this is of help?
It tells what will not be power if both IDG’s or off by the back up system:’
Thanks, but I’ve already seen that.
The wording in that description would seem to assume that the bus tie was operative – that is, other sources of power could supply the left bus via the bus tie.
The question would be: If the left main generator, left backup generator *and* bus tie had been disabled, what (if anything) would supply power to the left bus?
Followed by: What would then be unpowered?
@Ge Rijn said: ‘Maybe another reason to re-energize the left main AC bus again at 18:25 could be the following in the list posted above:
-Center tank override/jettison pumps (center tank fuel is unusable and cannot be jettisoned)’
According to the FI, the aircraft was not using its centre tank, just the wing tanks.
@Ge Rijn said: ‘If switched off ALL components of the IFE are switched off. So if it was switched off before 0:19 I can imagine there would be no IFE log-on:’
But if you didn’t turn off the IFE switch, but just disabled the left bus and tie, the IFE switch would still be in the ‘ON’ position when the left bus and tie were re-enabled, hence the login. But (perhaps) no one alive by then to send any SMS or emails.
@Littlefoot said:
‘If Nederland is right, then we have no indication whatsoever that the left AC bus has ever been pulled. It might’ve happened – but we can’t know for sure.’
Not sure exactly who said this now (INMARSAT? ATSB?) but I seem to remember early on it was determined from the SATCOM log data specifics that the 18.25 logon was consistent with the SDU being re-powered.
@PHS said:
‘As if per the suggestion of Rob the sdu was de-energized by switching to back up generator, the only available autopilot was the third with limited functionality (?)’
All three autopilots are the same – there isn’t a ‘more advanced’ one.
@Middleton
Perhaps I didn’t explain sufficiently. As I see it, there is only one way you can switch off the IFE without switching off the video cameras, and that is by de-energizing the SDU (SATCOM). And there are only two ways you can de-energize the SDU from the cockpit, either isolate LH main AC bus, or switch to backup generator and force load shedding of the SATCOM. If isolating the LH main AC bus would also de-energize equipment that the pilot needed to keep operating, then he would have opted for the backup generator/load shedding option.
I don’t have a list of all the various items supplied from the LH main AC bus. I know the IG looked into this question. They might be able to help you on that. If my memory serves me, the SATCOM, TCAS, pitot heating and cockpit door lock are on that list.
With regard to the desirability of keeping the video cameras operating during the first hour, I can only say I would think that the video cameras would give a much better idea of what was happening the other side of the door than a spyhole. That is why the cameras are fitted, and they allow you to monitor the cabin without having to leave the pilot’s seat.
@littlefoot
I agree we cannot know for sure but if this was all planned the perpetrator especialy if he was a experienced pilot/instructor (like Zaharie) would probably have known the SDU was powered by the left main bus.
It seems to me the easiest way to cut power to the SDU is to push the left bus tie ‘isolate’ switch on the overhead panel in the cockpit or push the left generator control switch to ‘off’ on the same panel.
Wrt to the centre fuel ⛽ tank: On this flight, the centre tank would not have contained much fuel initially. This flight had 7.5 hours worth of fuel uploaded. The B777 ER has enough tank capacity for 11 hours, plus reserves. The wing tanks are filled first, followed by the centre tank. What’s more, the centre tank fuel is used up before fuel is taken from the wing tanks. All this means that the center tank was probably empty by the time the aircraft was commandeered, so the centre tank fuel transfer pump operability is not an issue, as I see it.
And then switch on the left back up generator which won’t allow power to the SDU by load shedding but will power the captain’s flight instruments.(switch also on the same overhead panel)
@Rob
I just read an earlier post from you and I guess you are right there.
To fall back on back up generators you have the swtch off both IDG’s and set the APU switch to ‘off’.
@Rob, thank you, but I wasn’t asking you to explain, I was posing a question generally in response to your posting.
@ROB said:
‘Perhaps I didn’t explain sufficiently. As I see it, there is only one way you can switch off the IFE without switching off the video cameras, and that is by de-energizing the SDU (SATCOM).
If, as you say, the IFE switch controls power to the video cameras, then switching off power to the IFE (however that is done) will also de-power the cameras.
@ROB said:
‘And there are only two ways you can de-energize the SDU from the cockpit, either isolate LH main AC bus, or switch to backup generator and force load shedding of the SATCOM.’
If you switch off the left IDG, isolate the left tie and use the left backup generator you would also likely (?) shed all non-essential loads on the left bus, not only the SDU but also the IFE since that uses a lot of power.
@ROB said:
‘That is why the cameras are fitted, and they allow you to monitor the cabin without having to leave the pilot’s seat.’
As you can see from the video I linked, the view from those cameras is likely limited to the area immediately outside of the cockpit door – not the cabin, which is what the perp(s) might be more interested in before they re-powered the bus, if that’s what happened.
There was an accident involving a Boeing 777-222, registration N786UA at London Heathrow Airport on 26 February 2007, as the plane was preparing for take off. The accident report published in 2009 identified the following as the main cause of the incident…
1. An internal failure of the Right Generator Circuit Breaker or Right Bus Tie Breaker contactor on the P200 power panel inside the Main Equipment Centre resulted in severe internal arcing and short-circuits which melted the contactor casings. The root cause of contactor failure could not be determined.
2. The open base of the P200 power panel allowed molten metal droplets from the failed contactors to drop down onto the insulation blankets and ignite them.
3. The aircraft’s electrical protection system was not designed to detect and
rapidly remove power from a contactor suffering from severe internal
arcing and short-circuits.
4. The contactors had internal design features that probably contributed to the uncontained failures.
Various safety recommendations were made in the report, and I wonder if Malaysian Airlines took the needed action?
Full report here, with a some interesting information about the B-777’s electrical power systems.
AIRCRAFT ACCIDENT REPORT 2/2009
https://assets.publishing.service.gov.uk/media/542303bced915d1374000bbb/AAR_2-2009_N786UA.pdf
I think it’s not unreasonable at all to assume that the perp did his homework and took out the SDU from the cockpit by design in order to stop people from making use of the satphones in business class. The possibility that someone would use the satphones must’ve been a legitimate concern. It might’ve seriously jeopardized his plans if a passenger or crew member had quickly alerted someone that the plane had been taken over and was in trouble. Depending on how the perp took out the SDU he might’ve also lost certain other functions he wanted or needed again after the danger that someone would make a satphone call was over. Therefore he might’ve undone whatever he had done earlier, and the result was that the SDU came back. So, the loss of the SDU might’ve been by design. But the comeback might’ve been a by-product. He either didn’t care because there was no one left who could make satphone calls or he even thought it might be useful to monitor incoming calls.
The perp might or might not have done all sorts of things which could possibly facilitate the takeover. But we have no way to know for sure what he might’ve done. All we know is that he did something which took out the SDU. And he also did something which brought the SDU back at 18:25 UTC.
And IMO a good case can be made that he knew how to take out the SDU from the cockpit.
@Gysbreght. “So what are you trying to prove?”
Ge Rijn’s question was, “Considering a descent with accelerating speed wouldn’t the fuel be pushed back in the tank and the fuel lines?
Like being pushed back in your car seat when accelerating?”
My answer addressed that…., “the pull forwards or to the rear of things in the aircraft (supposing no engine thrust) depends on their tendency to accelerate along the aircraft axis more or less than the aircraft. The difference between the two (the thing and the aircraft) will be the aircraft’s drag/divided by its weight (for small descent angles the inverse of lift/drag) multiplied by g.”
Your response was, “Actually, mr. Newton would disagree. The “things in the aircraft” are subject to the same acceleration as the aircraft itself, …”
So what then I found myself needing to prove was that my answer to Ge Rijn could stand and that you were misrepresenting Newton..
I would have thought that obvious.
@Middleton
@Middleton said “If you switch off the left IDG, isolate the left tie and use the left backup generator, you would also likely (?) shed all non essential load on the left bus, not only the SDU but also the IFE, since it uses a lot of power”
Putting a question mark after “likely” was appropriate, because it is not likely, in fact it wouldn’t happen. The Load shedding is controlled by the ELMS, which would shed SATCOM, TCAS, and the RH HF radio. The IFE would not be load shed, as I understand it.
And the pilot (perpetrator) would want to monitor the area outside the cockpit door, using the video cameras, to be alerted of any possible attempt to force entry to the cockpit. He would not need to be able to see down the cabin, he would be more interested in any activity taking place immediately behind the door.
Flyht Aerospace has the answer:
https://www.youtube.com/watch?v=fkeqgXNbLvo
So is it possible to execute all power isolations cleanly at around IGARI and done before BITOD in such a way that the aircraft disappears from all RADAR signatures and stopping satcoms. To me it seems a lot to accomplolish in tight timelines and do it successfully.
Just to add to my last post … With the consideration that there are multiple buses and backups with aux power generator and batteries.
@Littlefoot:
If a perpetrator switched off the SDU to stop the voice recorder, then he had to switch it on again, wouldn’t he?
Might be difficullt to isolate that from other benefits but you need not hesitate much on that it had to be turned on again. And there you have half (a quarter?) a perpetrator profile. And it is not a jihadist.
Could he have chosen to turn on and off the voice recorder without going through the SDU?
And it seems pretty obviuos, doesn’t it, that if this is an extended suicide then the communications have to go. For as long…
How did the passengers die? Can a pilot effectively depressurise the aircraft through the push of a button or pulling a fuse?
@ROB said:
‘Putting a question mark after “likely” was appropriate, because it is not likely, in fact it wouldn’t happen. The Load shedding is controlled by the ELMS, which would shed SATCOM, TCAS, and the RH HF radio. The IFE would not be load shed, as I understand it.’
Do you have a source for that?
The IFE is either shed or it isn’t – that needs checking, hence my question if anyone reading has access to a 777 AAM.
I said ‘likely’ because non-essential loads would be the first thing to be dropped – IFE is a high-power load and, as the abbreviation denotes, is only for entertainment.
Why would IFE be kept when other, more important, things such as SATCOM, TCAS and HF radio are being shed?
@Johan
“How did the passengers die? Can a pilot effectively depressurise the aircraft through the push of a button or pulling a fuse?”
The pilot can depressurize by switching the by pass oxygen..Which is located upper panel behind Captains seat by memory..
Questions in regards to latitude,longitude decimals found on Zaharie flight Sim..
I had a look at FSX waypoint info..FSX ONLY display’s first 4 decimals for example..
LatitudeN22*.09.62 Longitude E114*.03.57
*I need to open a drop box so and attach the screen shot for all to see.
Did the investigators add on all the decimals on the Data retrieved..
@VictorI,
I will comment on the possibilities you mentioned insofar as they might offer some reduced fuel consumption for 180 degree True Track routes through BEDAX:
“1) The exact route flown before 19:41. For instance, it is possible that after 18:28 the plane flew at low speeds on N571 until 93.8E longitude and turned directly south. The low speed would reduce fuel flow, making more fuel available later in the flight.”
The problem with this suggestion is that the 18:40 phone call would have occurred during the northwest leg at reduced speed. In order to match the 18:40 BFO with a northwest bearing a significant descent rate is needed. That means that at the FMT the altitude is reduced. If no restorative climb occurs after FMT, the southbound leg is then flown at an inefficient, low altitude, and the savings from the slow-down and descent are offset by the higher consumption on the southbound legs. If a climb also occurred after 18:40, that climb more than offsets the fuel savings due to the previous slow-down and descent. The net positive impact of this scenario will be fairly small – far too small to bring the PDA up to an acceptable level.
“2) The possibility of changing altitude to maximize fuel efficiency.”
Actually, this is not an additional degree of freedom, since matching the satellite data determines the average speed, and the optimized altitude is based on the FCOM table to match that speed. Thus efficient flight, which is built into the FCOM tables, is already taken into account. In other words, the altitude is varied so that the FCOM speed at that altitude matches the satellite data.
“3) Uncertainties in temperature and wind fields.”
These uncertainties are fairly small and cannot produce significant fuel savings compared to the ~3-4% shortfall.
“4) The possibility of a (low thrust) descent in the later portion of the flight, which would reduce fuel consumption.”
This is unlikely to produce significant fuel savings, simply because going into 00:11 at low altitude appears incompatible with remaining in the air at 00:19 and with the 00:19 BFOs indicating a very rapid descent. Descending well before 00:11 is also incompatible with achieving the relatively high average speed required between 22:41 and 00:11 without burning extra fuel to maintain the matching speed after the descent while at low altitude and therefore offsetting the benefit of the descent.
My contention is that a shorter route, with a lower average speed, must have been flown in order to match the known endurance with expected PDA values. True Heading and Magnetic Track routes are several hundred air miles shorter than the True Track route, even the 180 degree one through BEDAX. That shorter distance produces enough fuel savings to move the PDAs from about -1% to +2-4%, in line with expected values, even with a descent down to FL100 and a climb back to cruising altitude.
@DrBobbyUlich
you said:
“The problem with this suggestion is that the 18:40 phone call would have occurred during the northwest leg at reduced speed. In order to match the 18:40 BFO with a northwest bearing a significant descent rate is needed. That means that at the FMT the altitude is reduced. If no restorative climb occurs after FMT, the southbound leg is then flown at an inefficient, low altitude, and the savings from the slow-down and descent are offset by the higher consumption on the southbound legs. If a climb also occurred after 18:40, that climb more than offsets the fuel savings due to the previous slow-down and descent. The net positive impact of this scenario will be fairly small – far too small to bring the PDA up to an acceptable level.”
What is the reason, that you rigouroisly have to assume a prolonged descent with the consequences you describe? The BFO at 1840 is just the tad of a second, where this descent rate to match the BFO has to exist. Even if we assume a descent rate over a full minute, the change in total altitude and the following correction back up to this altitude is negligable comcerning fuel. Before that FMT the aircraft could have been maneuvered manually, and to assume an straight and level flight without deviations like being flown on autopilot fails my reality check.
@Johan. ” Is it established if the infamous inflight system reboot happened directly before or after the FMT?”
The ATSB has said (P16, December 15 2015 update), the “turn south was modelled at 18:28 – this is the earliest that the turn could be achieved based on the analysis of the satellite data and also provides the maximum southerly range.”
The SDU reboot started at (“approximate time”) 18:24:27, the log on request a minute later. IFE SATCOM SMS/email was set up at 18:27:03 and BITE followed at 18:28:05.
The two very proximate if the “earliest” was the actual.
@Dave: The part of your post that I found objectionable was this:
If the path is uphill, masses in the aircraft still “fall to the nose” (uphill relative to the aircraft) when thrust is less than drag.
@littlefot
“The possibility that someone would use the satphones must’ve been a legitimate concern. It might’ve seriously jeopardized his plans”
And the thought of jets would be scrambled were not??
@MH
“So is it possible to execute all power isolations cleanly at around IGARI and done before BITOD in such a way that the aircraft disappears from all RADAR signatures and stopping satcoms. To me it seems a lot to accomplolish in tight timelines and do it successfully”
It’s weird isn’t it. Almost too good to be true that one man could have done this.
The airplane disappears from ATC radar when the transponder is switched off.
SATCOM stopped at some time between 17:07:49 and 18:03:41
ACARS communication stopped at some time between 17:07:49 and 18:25:35
@Trond
As far as I can see it seems not difficult at all to do by one man.
There is one rather small overhead ‘electric’ panel with all the switches necessary grouped logically above the captain seat.
I think in a matter of seconds those switches are pushed by someone in the captains seat.
A picture of the panel:
https://www.dropbox.com/s/3jp9o8imb06fzw9/b777%20electric.jpg?dl=0
@ Gysbreght. I agree that I should have stuck to down hill. But if that was your only objection there would have been no problem. However I do not think from your posts that you have cottoned on to the difference between thrust induced acceleration and that of gravity. One example:
Ge Rijn, “So if thrust and drag are carefully controlled in a steep accelerating descent I can conclude fuel in the tanks will not move forward or backwards?”
Your answer, “Yes, that is correct.”
If you agree now that in an ACCELERATING descent induced by gravity, forgetting thrust but with some drag, fuel (including that in the APU fuel line) will move forward or tend to, we will have no reason to discuss this further.
@Trond, the scrambling of fighter jets would’ve indeed been a major concern – and it would’ve happened with certainty and fast if someone had informed about the hijack by using the satphones. That’s why I said they might’ve been a legitimate concern.
I may have expressed this thought twice, since my first answer to you got lost in cyber space somehow. Sorry in advance if it turns up later.