Last month, I published an article in New York magazine about a secret Malaysian police report which included details of a simulated flight into the southern Indian Ocean. As Victor Iannello revealed in a comment earlier today, that information came from French journalist Florence de Changy, who had come into possession of the full police report but only shared a portion of it with me.
I have not seen the full report, but would very much like to, because I would like to form my own judgement of what they mean, and I think everyone who is interested in trying to figure out what happened to the missing plane, including the next of kin, are entitled to the same. Some people who have read the full reports have suggested that they give the impression that the recovered simulator files do not in context seem all that incriminating. Other people who have seen the full report have told me that the report contains material that makes it hard to doubt that Zaharie is the culprit. Of course, it’s impossible to rely on someone else’s say-so. We need to see the full report.
The reason I am writing this post now is that earlier today Florence published an article in Le Monde in which she describes having the full report as well as another, 65-page secret document on the same topic. Meanwhile, another French newspaper, Liberation, has also published an article indicating that they, too, have a copy of the report. And private correspondence between myself and a producer at the television network “France 2” indicates that he has as well.
Meanwhile, I know that independent investigators here in the US have the documents as well.
At this point, the secret documents are not very secret. Someone within the investigation has been leaking them like crazy, obviously with the intention that their contents reach the public. My understanding is that this source has placed no restrictions on their use. So journalists and independent investigators who have copies of these documents need to do their duty and release them — somehow, anyhow. Some people that I’ve begged and implored to do so have said that they fear legal ramifiations. Well, if it’s illegal for you to have these documents, then you’ve already broken the law. Use Wikileaks or another similar service to unburden yourself.
Free the data!
UPDATE 8/14/16: Apparently Blaine Alan Gibson has the document, too, according to a rant he post on Facebook. He reveals that the entire set of documents is 1,000 pages long.
@Dennis
One of the reasons I visit this blog is the maturity of the dualogue and the respect conveyed to others. Implying that other people need medication because you don’t agree with them is rude.
@PatM
Accepted. You are right.
@Dennis
As soon as personal insults substitute content, sure to be a sock puppet troll.
@Johan
“@Dennis
Being on the same page, I’d love to hear more about this:
“The suicide theory has never made it to the top of my list. I still advocate a diversion performed for a political motive that somehow went awry. I do not believe that Shah intended to physically harm anyone including himself.”
… In the morning.”
……….agree, to not wanting to harm anyone.
I spent a decade in Malaysia, the profile the “authorizers” of the rogue pilot theory, counting on the fact of the general population outside the region (aka The West) lack of local knowledge, of understanding of Malay people. They have him portrayed as something so counter to my experience of travel with MAS and Malay professionals, working with the airline. Too chilled out they are to fit the profiling being done regarding the pilot/s.
Westerners we have been Pavlovian trained to react in the negative to anything under a label of Islam but the reality is people of the educated class of the pilot are both worldly and calmed by their faith. Take him and the young co-pilot out of the negative profile scenario, the preferred patsies, who is responsible and if the plane did not ditch in the SIO where is it?
@David,
The APU inlet door position switch indicates closed when the door is 70% open; >70% it indicates open.
OZ
@Gysbreght, Ge Rijn, DennisW. I hope this helps get this subject off these pages.
This started at Ge Rijn’s question as to what would happen to fuel in an accelerating descent due to gravity. After approximations and scene setting I drew up and posted an indicative and simple equation addressing this. One of the approximations was that the fuselage axis was aligned to the direction of travel. This entailed the approximation of Cosine of a smallish angle being 1. Gysbreght reasonably pointed to a two speed horizontal steady speed example where this approximation would be inappropriate. It pointed out that 1 degree of pitch increasing to 4 altered the fuel tank angle, the fuel level remaining horizontal so becoming deeper to the rear. My response was to reassert the applicability of my equation in the direction of travel but did not address the diversion of the fuselage axis from that.
I agree that the tank angle changes, so no further explanation is needed by me. However what I remain focussed on is the consequence of an early dive, suggested by the second 7th arc BFO. The chances are that a gradual and small pitch change he describes would be subsumed in other pitch changes, autopiplot disconnected.
I stand by my simplified equation as indicative of what could be expected of the fuel in a gravity induced acceleration.
My equation, that is: Restraining Force needed on an internal object or substance in the direction of motion equals Object Weight X Aircraft Drag/Aircraft Weight is general, ‘Drag’ being a vector quantity representative of the net force opposing motion in the direction of travel. An example of its generality is interpretation of a ‘what if’. What if Drag/Weight was 1 in a shallow dive? How could that be explained? Answer would be that the aircraft would have high acceleration to the rear, under that “Drag”, ie this represents reverse thrust, such that the restraining fore on the object would be its weight.
Which leads me to Ge Rijn’s lorry C. His was accelerating under gravity but without thrust, this case referred to by Gysbreght as Lorry D (I think!). Gysbreght wrote, “Lorry D is accelerating, so the fuel moves rearwards until its surface is perpendicular to the direction of the sum of the accelerations of vehicle and gravity”. In my opinion that can be made more specific. The fuel would lie parallel with the truck bottom when drag is nil, moving forward to horizontal as drag increased to the Truck Weight X Sin(angle angle of descent; (the forward force then resisted by the truck front is the Sin(angle of descent) X fuel weight, the truck being at constant speed. More ‘drag’ (ie negative thrust) than that and the fuel goes forward more, the truck now accelerating uphill.
@Oz.”If the inlet was in the centre of Gysbreght’s lorry, how much fuel is usable”? The maximum proportion accessible would be when the fuel surface is parallel to the truck bottom, as above.
@Ge Rijn. I will be happy to look into the centre tank when I can.
@OZ. “…>70% it indicates open.” Thanks. Please let me know where you got this from. I am unsure which should carry the more weight, that or the “..must be fully open” I quoted.
A further quote, SmartCockpit Systems Summary (Engines and APU) p29 notes, “When the APU air inlet door reaches the full open position the starter engages.”
A graph I have of the engine start cycle does not carry times. However proportioning the opening time to the start length, assuming this is 60 secs, gives 35 secs, not that that is firm evidence.
If 70% of 30-40 secs it is 21-28 still, say 25 sec but worth knowing which.
@MH
How would you know when, where and how to hide?
@Ge Rijn
I have some doubts. In my example lorry C did not reffered to lorry D. Lorry D was accelerating downhill due to gravity and applied (engine)thrust. Lorry C without applied (engine)thrust.
On the lorry there is drag working from the air and the road. On the fuel there is no drag like this but only gravity and inertia working.
If so much thrust is applied downhill that the inertia of the fuel equels the forces of gravity (acceleration) the fuel surface will be horizontal related to the bottom of the lorry (as you say).
But if more (engine)thrust is applied this balance will shift and the fuel will move backwards because inertia of the fuel mass cann’t keep up with the acceleration anymore.
This were my thoughts on the matter and I thought it was settled. But maybe I misunderstood you both in some ways.
And I have doubts about your anwser to @Oz.
First I think it depends on where your fuel-inlet is; on the front, the back or in the middle of the tank.
Second; when downhill (or descent) only accelerating under gravity more fuel will be above the inlet if the inlet is on the front then when driving (flying) at constant speed horizontally.
I think depending on how high the inlet is from the tank-floor then more fuel will be available in a descent (if the inlet is at the front of the tank and less if it’s at the back).
Hope you don’t get a headache from this all..
I would be glad to hear your opinion on the center tank fuel scavenge system.
Just in case this 1300kg of fuel was not taken into account at the end of the flight when main tanks where running empty could mean a lot to the duration of that end flight as you understand ofcourse.
Thanks in advance.
@Gysbreght, Ge Rijn, DennisW. My above. beginning of paragraph 3. “My equation, ….in the direction of motion” add, “.. where the aircraft is accelerating in that direction under gravity…”
@David
Previous post was meant for you in the first place.. not for myself 😉
@David: If you want to take the subject off these pages, that’s OK. If laid out the physics for you. If you know better, that’s fine.
@Ge Rijn. As I remember it, Gysbreght’s lorry C was at a steady speed, your was accelerating under gravity. Gysbreght’s lorry D was accelerating. From your paragraphs 1-3 we agree as I see it.
Oz specified a centre outlet, which was what I addressed. No headache but sometimes a muddle.
@Gysbreght. My first sentence expressed a hope not a wish.
@David @Jeff Wise @all
@David you are right that was a difference between my lorry C and @Gysbreght’s lorry C.
I think it’s all settled then.
On the data:
http://www.duncansteel.com/archives/2798
The IG statement ignores all anomalies in the data, presumably that is addressed in point 9: “Work continues within the IG to better understand and validate the data”.
It is a matter of opinion whether it is unduly suggestive to state in point 6 that : “the alignments of the points and the progressive depletion in fuel level, (…), suggest the coordinates may well be related to the same flight simulation.”
That alignment of points and progressive depletion of fuel exists only until the turn to heading 255.5°, which is not pointing towards McMurdo, and 20,000 kgs of fuel are not accounted for.
In fact there is absolutely nothing that suggests a connection between two coordinates the are separated by 3400 km and 64,372 kgs of fuel.
Incidentally, Jeff’s fuel quantity corresponds to 141,915 lbs. Why is the IG’s figure different?
Sorry, that should be 3,400 nautical miles.
@Brock McEwen
(From a posting 12th August)
I’m inclined to agree with the possibility that the ISAT data is a snow job (or fog) intended to obscure the real location of 9M-MRO.
That Captain Shah ‘did it’ will move up a notch in my mind when the phone transcripts to Prime Minister Najib Razak and trasnport minister Hishammuddin Hussein by Shah requesting a cover up are released. I await these keenly.
The only way to progress this are the forensic reports on the Pemba and Reunion wing fragments. Specifically;
(1) Separation by flutter prior to entry into the SIO (as per IG group).
(2) Crashed at high speed into the SIO with 9M-MRO (unlikely due to the well preserved nature of the pieces)
(3) Controlled ditching. This conflicts with the ISAT data assuming it’s not a snow job. Also the wing fragments from 9M-MRO are remarkably well preserved even compared to the Hudson Airbus ditching. Comments about possible wing damage to the later when removed from the Hudson river are noted.
(4) Landing, failed political plan with 9M-MRO and subsequent removal and planting of pieces to make it look like an accident (yes @DennisW the wacko hypothesis).
Surely forensic metallurgical analysis of the hinge/separation points will help tease out the differences.
@DennisW:
I thought as much. Personally I would hold a political hijack from Shah’s side as even less likely than a suicide. It actually slightly reinforces the possibility of a suicide, since a political hijack would not meet any success at all, only public disgrace for him and his family. If he didn’t plan on dropping leaflets on KL without anyone realizing it was him. He is a family guy by the way, and if he has a weak spot it is more likely there, not in politics. His protest would be mute, that much corresponds.
Speaking of which, the motive you stated a while back is (thus) not very likely to me (as a motive). Until much more turns up there. It is a motive for being late with the income tax reveneue, or littering, not mass murder.
I find your thought that he originally planned to use a flight to Europe for his abduction plausible (but doesn’t that affect your “political highjack” theory?) but perhaps it less likely that he would have abducted a plane at IGARI without much planning. He could have done that on paper overnight, if prepared in other regards, sure, but it still sounds pretty daring.
@Gloria:
Are you sure Malaysian authorities are behind the scapegoating of the pilot/s, or is it merely parts of the press who are trying to rub the backs of their intended (lower social class? / or morally impeccable middle class?) readers?
@Gloria:
… I mean the comments on the flight simulator from the Police have sounded pretty nuanced thus far.
@SteveBarrett
-‘Controlled ditching. This conflicts with ISAT data assuming it’s not a snow job’.
I suppose you mean this does NOT conflict with the ISAT data?
At least not neseccarrily IMO. It would only conflict the 0:19.37 BFO which was deamed unreliable by Inmarsat and the expected 0:21 IFE log-on. Which can easily be explained if the IFE was switched off before 0:19 as the ATSB stated.
@Trond – it would take knowledge far greater than what Shah could do by himself is my gut feeling.
@David @Oz
Just one more on the fuel.
I see 3 outlets for the fuel starting from the center in each main tank going to the back.
No one up the front.
So when in a descent only accelerated by gravity with near empty main tanks the APU won’t get fuel anymore at a certain point.
But I also see there is an APU feed from the center tank. There is 1300kg fuel left there as the main tanks run empty.
So IMO the APU will only run out of fuel after the center tank fuel is scavenged to the main tanks and consumed.
A graphic picture of the fuel system:
https://www.dropbox.com/s/633wkdiin6m5if2/B777%20fuel_diagram.jpg?dl=0
@StefanG
I basically think something like that (and irrespective of whoever seems to have hijacked that plane) is a reasonable scenario. I have also pointed to inherent difficulties in the deliberate depressurisation scenario.
I guess we have to wait and see what comes out of the flap examination. If it can be conclusively shown that it was deployed, then the ghost flight necessarily is off the table. Other than that, the ATSB reports indicate, to me, it is possible that some final part of the flight (say, at some point before Christmas or Cocos Islands) was on autopilot with no further pilot inputs, even though the assumption of a ghost flight just after the FMT means the plane would be in the search area.
@David
I am not ignoring you or even forming an opinion on the fuel issue. The physics are as stated – surface of fuel orthogonal to the vector sum of accelerations acting on it. Translating flight dynamics into accelerations is outside my comfort zone.
Ge Rijn:
Re: “But I also see there is an APU feed from the center tank. There is 1300kg fuel left there as the main tanks run empty.”
Can you provide references for these two statements? How is it known that there was 1300kg in the center tank? Where was this reported?
Information from the Continental B777-200 training manual shows that the APU can only draw fuel from the left tank. ATSB reported the same thing…left tank only. The training manual includes a diagram showing a different topology from the diagram you posted. It shows the APU can draw fuel from the left tank only, and it also shows the backup DC powered pump not shown in the “simplified diagram” you provided by link.
https://goo.gl/S27BcK
Just to extend DennisW’s comfort zone:
The equation of motion in the direction of movement (i.e. along the flight path) is given by:
dV/dt = T – D – W*SIN(FPA)
Where V= true speed relative to earth
T = thrust component along flight path
W = weight = mass*g
FPA = flight path angle.
Pitch is the angle between the airplane longitudinal axis and the horizontal plane.
With wings level Pitch = FPA + AoA, where AoA is angle of attack.
Note that for the flight dynamics only (thrust minus drag) is important. Distinguishing between thrust and drag is immaterial and is in practice always somewhat arbitrary.
ICYMI…Complete section on APU fuel from Cont. Manual here:
https://goo.gl/LlSrGt
Correction: The left part of the equation should read m*dV/dt, where m = mass = W/g
and D = drag
g = acceleration of gravity
@Brian Anderson,
The equations and software needed to maintain any of the five possible lateral navigation modes are quite simple in principle, but I do not know what is actually implemented by Honeywell in the FMS.
What I do know can be found here on pages 149-150:
https://drive.google.com/file/d/0BzOIIFNlx2aUTDlfTUNTZDVxb3c/view?usp=sharing
The Honeywell FMS Pilot’s Guide says it “ . . . maintains its existing track.” That disagrees with what you were told. A second-source document from an airline says “heading”, and there are second-hand reports of B777 pilots also saying it is heading. Honeywell knows what it actually does. Boeing knows what it actually does. Maybe even the ATSB knows what it does. It’s too bad no one will answer the question definitively and publicly. I wonder why?
To complete my brief introduction to flight dynamics, the equation of motion can be rewritten as:
(T-D)/W = (dV/dt)/g + sin(FPA)
For lorry B FPA=0 so (dV/dt)/g = (T-D)/W
For lorry C dV/dt=0 so sin(FPA) = (T-D)/W
As Dennis W said: “the physics is actually very simple”.
“The ISAT data is a snow job (or fog) intended to obscure the real location of 9M-MRO.”
O yeah. Presumably the Earth is flat despite all evidence to the contrary, and that is why all calculations have been misleading. MH 370 just fell off.
@airlandseaman
This was my reference:
http://www.flight.org/the-boeing-777-eicas-fuel-scavenge-system
@airlandseaman
This was my other reference:
http://lessonslearned.faa.gov/ll_main.cfm?TabID=1&LLID=79&LLTypeID=2
@Johan: You can find my reply to you on page 2.
I assume you haven’t seen it due to its delayed release.
@All Re fuel tank level. This is more complex than just tilting the tank and fuel . Tank sloshing fluid dynamics is a subject on its own . Any change in acceleration on the fuel in an in closed tank can produce violent wave patterns which are hard to predict with out knowing the exact fuel to air ratio, internal dimensions and baffles .I am sure engineers at Boeing can shed some light on the subject ,but here is a link to a 3D software program as an example of Sloshing . https://www.youtube.com/watch?v=LlkzyV7j3GE
Bobby,
You wrote: “the five possible lateral navigation modes”.
What are these 5 modes? My understanding of FCOM is that there is a total of 9 roll modes, though only a few of them can be manually selected by a pilot.
Re “Honeywell knows what it actually does. Boeing knows what it actually does. Maybe even the ATSB knows what it does. It’s too bad no one will answer the question definitively and publicly. I wonder why?”
Presume the original cause was a technical failure. Now apply favorite Dennis’ approach – look for a possible motive. It is on the surface. Does it answer your question and explain why ATSB, Boeing, etc. are reluctant to share this sort of information?
@DrBobby,
I know what the manuals say, and I’m aware of the apparent conflict between the statements . . maintaining the current “heading”, vs maintaining hte current “track”.
However, you have to put aside the literal interpretation of these statements because they are written to explain the behaviour in normal circumstances, and in situations where the crew would be expected to be monitoring their flight path, and respond accordingly.
The fact is that both of these interpretations are accurate at the point that a discontinuity occurs, . . for a short period of time. They do not necessarily represent what the aircraft will do without further action by the crew.
The information I obtained from honeywell was very specific about one point. A “snapshot” of the current magnetic heading is taken at the discontinuity, that heading is maintained, and there is no Track Hold method associated with that scenario.
That still left some questions unanswered but Honeywell did not respond to my further questions.
Ge Rijn:
Your references do not apply to MH370/9M-MRO. Use the information (ACARS Fuel) in the FI. There was no fuel in the center tank.
The APU can only receive fuel from the left tank. The line that connects the left tank and the APU goes through the center tank (no connection), so maybe that is where you are getting confused.
Comments on Egyptair flight 804 investigation:
http://www.theaustralian.com.au/news/world/the-times/egypt-air-crash-coverup-fears-as-egyptians-go-silent-over-cause/news-story/a367f8550ccc936f0e324a1a8b498c91
Apologies. Paywall. The Australian article, ex The Times:
THE TIMES
Egypt Air crash: cover-up fears as Egyptians go silent over cause
An EgyptAir plane on the tarmac at Cairo international airport. Picture: AFP.
DOMINIC KENNEDYThe Times9:47AM August 15, 2016
Investigators have come under fresh pressure to break their silence about the mysterious crash of an Airbus passenger jet in the Mediterranean as victims’ groups demanded an explanation over an alleged mechanical fault.
A lawyer for families of the victims of EgyptAir Flight 804, which plummeted into the sea killing all 66 occupants in May, said yesterday that it had experienced fire warnings before taking off from Paris to Cairo.
The automatic data system on the aircraft transmitted smoke alarms to the Egyptian maintenance base en route to Paris, but it was allowed to take off again for the night flight home, Sebastien Busy, representing 19 families, told Le Journal du Dimanche newspaper.
The Egyptians have failed to respond to requests from the French transport police, who are assisting a judicial investigation into the deaths, to disclose maintenance records, amid suspicions that information was being withheld.
Flight 804 crashed in Egyptian air space in the early hours of May 19 with no mayday signal or distress calls from the flight deck.
The Egyptian civil aviation authority issued 25 bulletins in the first two months after the Airbus 320 crashed, but has said nothing for four weeks.
“The preliminary investigation has confirmed the existence on this aircraft of technical failures which preceded the May 19 Paris-Cairo flight and EgyptAir should have been aware,” Mr Busy, a lawyer with the French National Federation of Victims of Attacks and Collective Accidents, said.
Stephane Gicquel, the federation’s head, said: “This aircraft should never have taken off again from Roissy [Paris] without a repair.”
He criticised the lack of information from the Egyptians. “It’s a total blackout. The Egyptians undertook to keep the families informed before their official communiqués. That has not been the case.” The stonewalling is fuelling fears among relatives that there may be a cover-up of the causes of the disaster. The dead included 30 Egyptians, 15 French people, two Iraqis and a Briton.
The limited information released so far is consistent with an electrical arcing fire in the avionics bay, a risk that may be associated with maintenance problems. No evidence has been disclosed that supports terrorism or a mechanical fault as causes.
French and US investigators, who are assisting the Egyptians by providing information and data about the aircraft and its parts, are said to be exasperated by the lack of transparency in Cairo. “The expression is ‘beating your head against the wall’,” a source said.
The French air crash investigation office and the National Transportation Safety Board of the United States, where the aircraft’s engines were made, have accredited representatives to the investigation.
France has finally lost patience and gone public with its annoyance. Jean-Marc Ayrault, the French foreign minister, took the unusual step of announcing that he had reminded his Egyptian counterpart that the families of the dead were still waiting for answers.
The findings are especially important for France because Airbus, the European aircraft manufacturing consortium, is based in Toulouse. The doomed aircraft was built in 2003.
Wagdy Gerges, whose brother-in-law Medhat Misheel was killed, said: “We haven’t received the bodies to bury them and we don’t have any updates about what is happening and what is going on.” Another relative told The Times that the last message families received from EgyptAir was on July 25.
The airline said then that Egypt’s technical investigation committee “has not at this stage indicated when an interim report will be issued”. Families said they had heard nothing directly from the investigation committee since providing blood samples months ago.
The relative said: “This is taking infinitely more time, it’s so much longer than we would expect. There is a lack of transparency. It’s as if they want us to forget this ever happened.”
EgyptAir, the state-owned national flag carrier, has previously been the focus of intense international scrutiny.
When Flight 990 from Los Angeles to Cairo crashed into the Atlantic off Nantucket in October 1999, killing all 217 people on board, the American authorities suggested that the co-pilot had deliberately crashed it. The Egyptians rubbished the US findings and blamed mechanical failure. In 2011, fire broke out on an EgyptAir aircraft preparing to take off from Cairo. Prompt evacuation saved the 317 occupants.
The Egyptians have repeatedly expressed annoyance at independent media reports about the investigation, at one point telling journalists to “abide by the official news”.
EgyptAir declined to comment, saying it was in the hands of the investigations committee. The Egyptian Civil Aviation Authority said it could not comment on the investigation.
Theories Explored
Hidden fire
Automated messages, known as Acars, sent by the aircraft just before the crash indicated an electrical power fault in the cockpit windows followed by smoke in a lavatory and in the avionics bay, situated below the flight deck. Experts say that these all suggest a fire inside the bay on the right side of the aircraft.
On the cockpit voice recorder, the word “fire” is heard. The flight recorder, situated at the back of the aircraft, stopped recording at 37,000ft, when the incident happened.
No fire in an avionics bay has previously been recorded on an Airbus A320, one of the world’s most popular aircraft.
However, the Royal Aeronautical Society in 2014 published a study Smoke, Fire and Fumes in Transport Aircraft, demanding wiring improvements.
Terrorism
France and Egypt are both key targets for Islamic State, but nobody has claimed responsibility for an attack. The final seven minutes of recorded actions by the aircraft do not support the likelihood of an explosion. Radars show that the aircraft lurched 90 degrees to the left, which is highly unusual.
However, it then settled into a more normal flight path. One possible explanation for the flight data recorder ceasing to record at 37,000ft would be if the plane broke up midair because of a blast.
Lithium battery fire
Lithium batteries in mobile phones, tablets and digital cameras are a potential fire hazard because they can burst into flames. The Royal Aeronautical Society says that on a typical flight, 100 passengers could have 500 lithium batteries. In 2010 a UPS Airlines flight caught fire because of a large quantity of lithium batteries in the hold.
Sabotage
There has been speculation about a photograph posted on social media by one of Flight 804’s cabin crew before the disaster. It showed an air hostess emerging from the sea, pulling a bag, with a crashed aircraft in the background.
The Times
@Ge Rijn. I think airlandseaman has answered your centretank query so I will leave it be.
@Gloria:
“But this narrative looks and smells too much like previous cover ups of major incidents.”
What previous cover ups are you referring to?
@airlandseaman
The first ‘Flight’ reference applies the B777. It says the center tank fuel pumps stop if there is still 1300kg fuel left in the center tank. This 1300kg will be scavenged to the main tanks if the main tanks run empty.
The second FAA-report reference applies a B777 200ER: BA flight 38.
9M-MRO is a B777 200ER.
What makes 9M-MRO so different?
Or do you mean this FAA-report and ‘Flight’ information is not correct?
In the FAA report fuel diagram you can clearly see the left center tank over-ride jettison pump is directly connected to the left main tank center fuel line which is directly connected to the APU fuel line.
What’s wrong with the information?
Hope you can provide a more detailed anwser.
@David
I believe you 1st mentioned the APU ‘air inlet opening time’ of
30-40 secs (without specifing that timeframes specific source).
That time is stated as “up to 40 seconds to deploy fully” in
training documents of the ‘Angle of Attack’ Flight Sim Training
and sim add-ons producer of that name;
https://www.scribd.com/document/271653768/777-GROUNDWORK-APU-TRANSCRIPT-pdf
I assume they quoted it from from a reliable source, but I
haven’t seen a mention of door timeframe elsewhere. I believe
it is reasonable to consider that other pre-start activities
of the APU startup (such as heating its oil) are within that
‘door opening’ timeframe, so perhaps the door opening is merely
the last (or merely the last notable) of those occuring
activities.
I would have thought that, in flight, the heating of the APU
“accessory gearbox and mid-frame bearings” (oil) is likely to
be the main impacting factor varying the starting timeframe.
OZ has stated (without noting source) that “APU start time is
approximately 60 seconds which is inclusive of the APU inlet
door opening”, and I also am inclined to regard that as the
current ‘working figure’, absent of any actual evidence as to
in-flight APU (from APU battery) startup time.
It’s worth noting that service testing of that APU model;
‘P-1342 Mini Pack.pdf’ (google)
gives a test result electric startup timeframe around 40 secs.
Given that the APU oil temperature in that test would be ground
temperature, time to heat its oil would be negliable.
_
(For in-flight starting, I have disregarded the ATS bleed air
start {from Main engine bleed air} as the {Main engine provided}
bleed air manifold may have some {slowly degrading} pressure in
it, but without any Main engine running to continuously
replenish the bleed air, it is questionable that a start via
ATS would be attempted, or be successful if it were attempted.)
“EgyptAir Flight 804”
So I was right. The Western MSM lied.
@David
Re EgyptAir crash: The Egyptian authorities’ attitude is worrying. They do appear to be engaged in a cover-up. If you remember, the Media was awash with conflicting information in the early days. Sounds familiar, doesn’t it. The Egyptians were behaving suspiciously, to my mind, right from the start, I mean the way they delayed downloading the recorders (ostensibly on the grounds of salt contamination!) And why did they insist on interpreting the recorders’ downloads themselves? I would have thought the French BEA or Airbus would have been better equipped for that task.
No, they have taken a leaf out of Malaysia’s book. Very convenient. And the ICAO’s obvious inability to enforce transparency on such issues will work in their favour, just as with MH370.
Don’t fly EgyptAir.
@Ge Rijn
Please don’t mix your terms. There is a ‘Centre tank’,
a ‘Left Main tank’ and a ‘Right Main tank’ on a 777-200ER.
(I think you may be typing your posts without fully checking/
considering them. I am guilty of this occaisionally, although
my sins are usually spelling and layout related.)
Also, you say;
“The first ‘Flight’ reference applies the B777. It says the center
tank fuel pumps stop if there is still 1300kg fuel left in the center
tank.”
I understand it means that when the Centre tank main pumps inlet can
no longer draw fuel, (because the fuel level is less than the level
of the main pumps inlet) that there is still 1300 kg of fuel actually
remaining in that tank. (From my reading elsewhere, I can state that
the Centre tank main pumps stop because it is sensed when those pumps
are no longer drawing fuel, so they are then automatically shut down
so as to ensure they are not damaged by attempting to pump {run} dry.)
You said; ” This 1300kg will be scavenged to the main tanks if the
main tanks run empty.”
Actually, precisely when it is scavenged is unknown, but your
flight.org referenced webpage said;
“Once sufficient fuel has been used from the mains (actually, once
LOTS of fuel has been used out of the mains) the scavenge system
kicks in” – this does not support your use of the word ’empty’.
_
HOWEVER, I believe this matter of 1300 kg, while worthy of being
brought to our notice by yourself, can be considered as unlikely to
apply to 9M-MRO. I base this on the FI stating that the flight deck
indications of 9M-MRO were that there was no fuel in the Centre tank.
Also (prior to the ‘disappearing’ flight) 9M-MRO flew a passenger
carrying flight KUL to PEK and then (presumably) a crew-only flight
PEK to KUL. Because the FI states that on its disappearing flight
that 9M-MRO took on no fuel to its Centre tank, it is reasonable to
me to consider it likely that 9M-MRO would also not need to take on
any fuel into its Centre tank when flying a previous PEK to KUL
flight with no passengers (and probably not carrying any cargo).
http://i.imgur.com/UUW6ReX.png
Ha, correction to the above post, should read;
‘Because the FI indicates that on its disappearing flight
that 9M-MRO took on fuel, such that the fuel quantity in
its Left and Right Main tanks increased – and as the total
fuel amount after refuelling equaled the amount in the
Left+Right Main tanks, this indicates that there was no
fuel in the Centre tank.’
@BuyerNinety. Thanks for the article: interesting.
I note it says, “When the inlet door reaches its full open position and the engine rpm is less than 12% the APU Controller commands either an electrical start, or a pneumatic start”. The referral to 12% I think applies to a run down. Hard to get there otherwise without starting.
My quote about the inlet door needing to be it being open (“the air inlet door sends a signal to the APUC and ELMS when the air inlet door gets to the open position”)and taking 30-40 secs is from the Training Manual, 49-10-00 p44. The second saying that it must be FULLY open before the start sequence starts is from the Training Manual 40-00-00 p124.
I followed that in a second post with a third quote, from Boeing 777 SmartCockpit Systems Summary (Engines and APU) p29, in which as I said it notes, “When the APU air inlet door reaches the full open position the starter engages.”
The diagram of the engine start cycle I mentioned (I called it a graph), which does not carry times is from the Maintenance Manual 49-00-00 p21. It carries a copyright notation. There is a segment of 23 secs (proportioning again) after the battery switch is turned on, before the 35 seconds portion I mentioned for inlet opening. This may be just nominal. I assume that the battery would be on already in the air and that oil etc heating would be as required but available continuously.
OZ has not responded about from whence his
70% open-at-start information came.
The only evidence I have for the 60 seconds from starter engaged to stable speed is what I said earlier. Loading is in fact available at 95% RPM plus 2 secs (the diagram p21) as your reference says. APU start is electric above 22,000 ft (TM 49-00-00 p124).
The starter cuts out at 49% RPM below 22,000 and 55% above that, presumably because self-sustaining speed becomes higher (TM 49-00-00 p124). I suppose the reason that no start times are quoted is because they vary a deal with conditions and engine acceleration times to and above starter cutout may vary. This MAY allow how the ATSB quotes a total one minute at altitude. The manufacturer will have a handbook but that is not publicly available so far as I know.
All this aside, were there no inlet opening time at all added, my reckoning as I have said is that the chances are high the APU would cut out before the log on was complete, that is if the second BFO is to be believed.
@DennisW. “Translating flight dynamics into accelerations is outside my comfort zone.”
Not so comfortable myself any more. I had 2 years post-graduate study at Cranfield in the UK and did the flight test there, twice. We would pursue out second order differential equations covering static and dynamic flight stability and margins and of course performance. If necessary we would integrate and transform the things, not with great pleasure or facility but necessarily.
These days my brain is a rust belt but still remembers enough physics to be able to stand steady in the morning, mostly. After dinner, well yes still though less frequently. So please rest comfortably in your comfort zone without a second thought.