In an earlier post I described research conducted at the GEOMAR-Helmholtz Institute for Ocean Research in Kiel which suggested that, based on reverse-drift analysis of the Rénion flaperon, its starting point most likely lay in the tropical latitudes of the southern Indian Ocean, far north of the current seabed search area.
Today the same scientists published an update of their research, with a press release available here and the full report here. The upshot can be seen in the chart above, which shows the probability distribution of where the piece likely began its journey to Réunion island. Once again the authors have concluded that the greater part of the probability (98.7 %) lies far north of the seabed search area, shown as a white rectangle. The study’s authors suggest that their results might justify a shift of the search area:
The Australian search authorities are aware of this report. “Whether or not these new results will be used to facilitate the last few months of the ongoing search for MH370 is not clear,” Arne Biastoch summarizes.
One of the refinements included in the new study is that while the authors continued to assume that there was no direct wind effect on the flaperon (it being presumed to be floating essentially flush with the surface), they have included for the first time an effect called Stokes Drift, which results from wind-generated waves:
“In our recent calculations we included more physical processes in order to simulate the drift more realistically,” Prof. Biastoch explains. “In particular the drift induced by wind generated ocean waves is now included,” Biastoch continues. “Even though we use state-of-the-art modelling systems, representing the ocean currents in the Indian Ocean quite well, all simulations naturally contain limitations. Our investigation is one important piece of the puzzle in finding MH370.”
As a result of the new calculations the possible source region of the flaperon was refined, and “While it is shifted a bit southward from the initial study done last September, our basic result that most particles originate from a region north of the current search area remains unchanged,” states Dr. Durgadoo.
So should Australian search officials call a halt to the current search and relocate its ships further north? Actually, I don’t think they should. If the GEOMAR scientists are correct and MH370 did crash into the ocean west of Exmouth, the plane must have been following a low and curving trajectory of the kind that is not supported by any simple autopilot mode. That is to say, the plane would have been either conscious control the entire time or flying along a series of arbitrary user-defined waypoints.
The latter seems extraordinarily unlikely. First, we would have to surmise that whoever was in control of the plane decided to fly a basically random path, and to choose a cumbersome way of doing so, entering by hand pairs of latitude-longitude coordinates. This would be bizarre behavior, to say the least. Furthermore, as explained in the DSTG report issued last December, it is extremely unlikely that a randomly chosen set of slow segments would happen to match the ping rings. Instead, random sequences are only likely to match if they conform to a fast-and-straight flight to the south: in other words, if they end up in the current search area.
The former is problematic for the same reasons, and for an additional one as well. If the plane was under conscious control until the bitter end, then we cannot assume that, as in the unpiloted scenario, it spiraled into the sea once its fuel ran out. Instead, the conscious pilot might have chose to hold it into a glide far beyond the seventh arc. We have no reasonable expectation, therefore, that a narrow search along the seventh arc would yield the wreckage.
Gysbreght,
FCOM does not seem to contain the details I am interested in. Otherwise I would not be asking.
@Oleksandr.
There are other examples offcourse. But they had human intervention. The Gimmy glider, Hudson landing, Azores glide and landing and even many more in the past.
I don’t know any except the Helios flight without human intervention. The Helios crash assumes systems adjusted to keep the plane level and the descent gradualy without human intervention.
The rudder would stay in position after first engine flame out until the APU kicks in after second I guess but this would only be for a minute or so.
After the APU stops I don’t know if the RAT and windmilling of the engines supply enough hydraulic pressure, AC current and the back up batteries to compensate.
I think redundancy wise they would (or at least should in those circumstances).
But without sufficient pressure and current I can imagine the rudder would be pressed by the air pressure in its neutral position.
The APU having an adverse impact on the situation after kicking in I hardly can imagine.
Getting most of the systems back on line it would urge them to correct any hazzardous situation first to controlable proportions I assume.
And another thing.
Considering a completly neutral plane without any steering surfaces deploid whatsoever everthing neutral.
It would be aerodynamicaly stable due to its basic inherant stability design.
Like the gliding model aircarft you throw in the air it will correct itself and even land gradualy and wings level if there is not too much disturbance in the air.
Ge Rijn,
A long while ago RetiredF4 has mentioned the “Cornfield bomber” case – miracle landing without human intervention. You can Google on it. The case of MH370 is indeed different. What would happen if APU was on by the time of the flameout of the second engine? Would AP stay engaged and control gliding?
Re the rudder.
According to Mike’s simulations it looks like the rudder immediately returns back to the neutral position after the flameout of the second engine (zero turn rate). What does control it? What does stabilise yaw after the flameout of the second engine?
Re: “The APU having an adverse impact on the situation after kicking in I hardly can imagine.”
The things rapidly deteriorate after APU kicks in according to Mike’s simulations. At least it appears so.
Re : “Getting most of the systems back on line it would urge them to correct any hazzardous situation first to controlable proportions I assume.”
Again, it does not look like electronics makes any attempt to correct the situation.
Oleksandr. “What would happen if APU was on by the time of the flameout of the second engine? Would AP stay engaged and control gliding?” Yes.
The APU auto start after aircraft AC failure is incidental and not a saviour. It runs for a maximum of 13-14 mins on some residual fuel, enough time to get flaps down maybe, electrically if the crew is aware it is going amongst their troubles. The rudder single engine rudder trim ceases at AC failure. Subsequent APU start will have no effect on rudder trim. The RAT provides a little power to a DC converter for DC supply only. The aircraft is mildly unstable when without autopilot. It is not designed or released to be to fly without neither a pilot or autopilot. Fly by wire is different to the old inherent stability requirements.
@Ge Rijn: I gotta agree with David above. A 777 without AP and hands off the controls is not stable and will bank over and enter a spiral.
@Ge Rijn, This has all been well discussed at great length, I don’t know if there’s going to be a big appetite for going through it all again. As for Helios, there was someone at the controls at the end, a flight attendant who’d received some flight training
@Warren
@Dennis
@MartinD
@ByronB
Warren, perhaps the book could be titled “Tracking down MH370, or how I learned to love the SATCOM data”
@Oleksandr.
I’ll sure google this ‘Cornfield bomber’ incident. Quite interesting.
The immediate return to neutral position of the rudder after second flame out could be the temporary loss of hydraulic pressure caused by flame outs of the engines and then the air pressure on this rudder pushing it back to neutral at those speeds.
The plane falls back on its inherent stability first I think.
After this when the APU kicks in the situation gets analysed by the computers and those make nessesary adjustments to avoid more problems first, awaiting pilot actions.
If those computers could be possibly programmed to deterioriate situations like this (and engine flame outs are not the most uncommon things that could happen) it would be a major design flaw.
Hardly imaginable with such a expirianced designer like Boeing.
What else would be the use of redundancy by computers if those would allready fail in the case of an all engine flame out?
The goal you would aime for as a designer/manufaturer is to keep basic control in every sitution.
And one of the first would be control in case of all engine flame outs especialy in the two engine configuration which was the first certificated on the B777 with a three hours limit to airports.
@ Ge Rijn, Rob, Warrane Platts
Title: “Give it another 2 (wasted) years and then jump to next adjacent haystack”?
7 weeks to go and then what?
Wrong Field.
Jeff,
“This has all been well discussed at great length, I don’t know if there’s going to be a big appetite for going through it all again.”
Yes, there is a big appetite. It is probably the real meaning of the term “re-search”.
@ Oleksanr et all
“Re-search”? You betcha !! You “experts” have had +2 years at this and since seen spent +S200M for what ? – nothing. Zero.
The (likely planted) debris does not match the Malaysians preferred story.
Get off your high horse(s) and re-think – from day 1.
The clues are out there ….
@Jeff Wise.
Yes I know but again perspectives are chanching. Old thoughts and facts become relavant again. Old questions are in need of a new light I think.
With changing of the facts of the new confirmed debris, all the new drift modelling, the new assumptions of the ATSB on a possible glide and ditch, it’s allowed to ask and evaluate old and new questions.
If there is no appetite to do this, progress becomes a lot more difficult imo.
David,
APU automatically starts when both IDGs (engines) are dead, but it can also be started manually any time.
If it was active on the moment of the flameout of the second engine, AP would stay engaged if I understood you correctly. Then upon APU flameout, it would attempt to restart again.
In other words, could the plane be gliding for some time before 00:17, so that the login 00:19 corresponds to one more APU restart?
At the risk of being howled down, I think it is time to go back to square one, to gate C1, at 16:00 utc, and re-do, meticulously, the Isat calibration at the gate. We can not do that without the full unredacted log. The “key” is there. We missed it the first time, or more correctly, it was “hidden” in the “redactions”. If Inmarsat is to have any credibility from here on, THEY have to release the FULL UNREDACTED LOG, regardless of what Malaysia says or wants.
@GortoZ
I know, it’s easy to get disheartened, who wouldn’t be in the circumstances. Truth is, the ATSB have been incredibly unlucky. But luck can change! They are now realizing what the rest of us have been trying to tell them since the year dot, ie. he deliberately set out to evade detection.
They have now entered the last chance saloon and musn’t mess up now. The message now is “go south young man”
@Oleksandr: The description I gave is all spelled out in the FCOM.
Transport airplanes are designed to be operated by competent pilots with the necessary qualifications. The pilot has the option to engage the autopilot and select appropriate modes, or to control the airplane without autopilot.
GortoZ,
The debris are consistent with SIO, but unlikely with the current search zone. You got it totally wrong.
Planting? That is nonsense in my opinion.
200M? Firstly, we are paid nothing. Secondly, 200M is a small budget in my opinion. It is even less than the cost of one B777. But to be fair, Australia, Malaysia, China and Boeing have to share the cost. Thirdly, Fugro collects a lot of data, so that the cost will be partially recovered.
@ Ge Rejin
” … with changing of the facts of the new confirmed debris, all the new drift modelling, the new assumptions of the ATSB on a possible glide and ditch, it’s allowed to ask and evaluate old and new questions
Changing facts? You’re still in the adjacent haystack but wrong field. Stop it – enough! Delusional.
At what date will you (and your camp) accede this? After +2 years you state, next door ? Glide / final steer will change everything? Wrong field chum. Had your chance – blown it!
Let us start over … without data your option is just that – an opinion – sorry.
@ROB@Warren
A problem I have with your conjectures (none of is has a scenario worthy of the theory label) is that flying at a more Westerly heading after the FMT (say at a course of ~220) he would have made the search even more difficult.
@Oleksandr
Ref Kate Tee; on the aircraft she saw, the cockpit windows were
visible, but there were no passenger windows. Given that 9M-MRO
had passenger windows, therefore it was not 9M-MRO.
Ref your “What is a chance for these cables to be simultaneously
cut by debris”?
Cables from the transmitter(s) to the antenna(s) are plural – but
why consider them? Cutting the cable(s) (or Cable, possibly
singular!) that carries the voice signal from the cockpit reduces
the problem to damage of a possible single cable (or single cable
run)
Incidently, I note your mention of the oxygen tanks – I assume you
are thinking along the lines of what happened to Qantas Flight 30…
Ref the “Cornfield bomber”, the Wiki states that aircraft was at
that time “trimmed for takeoff” – therefore trimmed for maximising
lift, and the engine set to idle. It’s probably fair to say that
the Delta Dart had a ‘dynamically stable’ airframe, in the sense
that it could settle into a stable glide in those given conditions.
(A paper airplane often glides and successfully lands itself without
human intervention also…)
A 777 obviously isn’t as ‘dynamically stable’ in unpowered flight.
@Ge Rijn
Also, as Jeff is probably too exasperated to point out, it has been
mentioned before that an individual 777 has a tendancy to be neutral
or have a (slight) tendancy to yaw left or yaw right, even with the
rudder in neutral position (even supposing the rudder WENT to neutral
position in unpowered flight). It is known that 9M-MRO had one of
the airframes that had a tendancy to slightly yaw even with rudder
in neutral position, therefore without inputs to correct that yaw,
it would begin to bank – the aircraft had no “inherent stability”
to fall back on…
Oleksanda et all
As an )occasional) Australian TAX payer I object to anyone spending that anoint of money on a “hunch”.
Frst principle of Aircraft crash analysis – 1) where was the last recording radar / voice) ? 2) where is the debris?
The current SIO meets neither requirement. The Malaysians sent you there and are pulling your proverbial.
These Principal Actors refused to fully release information around items 1 and 2 – why.? And you arm-chair analyst pontificate about desirable “glide paths” or waters gently flooding the aircraft!
Delusional.
@Dennis
At 220 deg he would have run out of fuel in darkness, and been much easier to spot.
He took a course at 186 deg.
Take a gun to those elephants.
@ROB
Good point.
@GordoZ
This is very rudimentary behavioral stuff “do onto others..”, “if you do not have something nice to say…”
We should have a unified goal here, reaching that goal has and will at times see a difference of opinion and that is fine, that is healthy and that is productive.
If your issues do not allow you to be present in a blog where your inout is generally respected and you in turn generally respect others, then there is no reason to be there.
We are adults, certainly knowing how to conduct ourselves, not a bunch of teenagers. As I alluded to before, it seems awfully cheap to continually denigrate someone with whom you disagree.
Anger and frustration have a most definite place in all of this, just not effective in this format.
When it is relegated to that level it becomes counter-productive and disruptive.
“input”
I suppose most people here would be aware of the fire on an Egyptair 777 in 2011. If you are not familiar with it, this summary illustrates how a sudden fire erupted in the cockpit without any obvious reason. The full investigation report is also linked to this:
https://aviation-safety.net/database/record.php?id=20110729-0
@ Suzie Crowe
Agreed and thank you for the opinion but aghast at the stance – people are not allowed to show divergence from the “apparent” norm”?
I worry that you are prepared to banish people who question the +2 year search – if that what you are saying?
Please publicly expand …. Astonished !!!
We are adults – so do not pontificate to others.
I accept your opinion – please reciprocate … and accept differing opinion.
https://issuu.com/homeworkping/docs/207745685-b-777-oral-study
XFR Buses power CTR Pitot heater, as well as CA / FO radios, and instrument & panel lights
RAT doesn’t power XFR buses
@ Suzie
To critique me to question the “current SIO guided / unguided” scenario that has taken +2 years and delivered nothing? Everyone is doing he same – can you hear ?
Stop criticising and get listening …7 weeks to go …..
https://www.faa.gov/regulations_policies/handbooks_manuals/aircraft/amt_airframe_handbook/media/ama_Ch15.pdf
L XFR bus powers Pitot Probe HTR L, and C / R are “similar”
@GortoZ
It is not my place to “banish” anyone. Please re-read my 3rd paragraph. IMO, it is effective if people are “allowed to show divergence from the apparent norm”.
@GortoZ
“2nd paragraph”. I am incapable of posting without error
@ Suzie
“If your issues do not allow you to be present in a blog where your input is generally respected and you in turn generally respect others, then there is no reason to be there.” ?
Really? Is what what Susie is saying ? Susses/s Blog? No Contention?
Let everyone know please ……..
Most people here are aware of it, but many discount it – Jeff for
instance, mainly because he believes the fact that the SDU on/off
was only possible by human intervention, some others perhaps ’cause
their ouija board or their tea leaves tell them it was all a
con-spir-acy.
But you say “without any obvious reason” – did you fail to read
that report(?), because it posits the reason as electrical arcing
causing the oxygen line to rupture.
(The report doesn’t mention that ‘ABO’ (Aviation Breathing Oxygen)
is mandated at >80% oxygen, and that that 777 oxygen line carries
that oxygen at approximately 70PSI.)
The report does state the base cause of the fault was “multiple wire clamps are missing or fractured or if wires are incorrectly installed”. Subsequent to the report, Boeing issued Service
Bulletin 777-35A0027 so 777 operators would be made aware of the
need to fix this fault.
Unfortunate indeed, isn’t it, that the MAS maintenance record facility was damaged by a fire, so any records pertaining to
whether this fault was fixed by MAS may no longer exist…
Edit, my last post, replying to @ABN397
@Ge Rijn
“The immediate return to neutral position of the rudder after second flame out could be the temporary loss of hydraulic pressure caused by flame outs of the engines and then the air pressure on this rudder pushing it back to neutral at those speeds.”
Please excuse me if my question is stupid, I have never piloted an aircraft with hydraulic system. But would the rudder return to neutral position immediately after loss of hydraulic pressure, or will it be left in it’s position because of absence of hydraulic pressure to move it back in neutral position?
Normally in a hydraulic system, to move a part, hydraulic pressure must be applied either way, if the oil is not pumped in one direction or another, the moving part rests in his position unless and until leakages let external force applied to that part to gradually move back. For example a mechanical shovel, if the driver stops the engine while the shovel is high in the air, the shovel won’t immediately fall to the ground by its weight, but will descent slowly as the pump is not perfectly leak-tight at that pressure. For this reason, workers lower the shovel to the ground when then leave the site to avoid an accident happening later if someone goes under the shovel and the line breaks. Now if the hydraulic system in an aircraft works the same way, the rudder won’t immediately return to neutral position by the air pressure in the absence of hydraulic pressure, but this may happen slowly depending on air speed. It’s not the same thing as with a mechanical cable system where the pilot must maintain muscular force with his legs to maintain the rudder extended right or left. Or I miss something?
@buyerninety.
I question to doubt your statement about inherent stability.
Inherent stability is designed to level out instability to a certain degree. With no input on controling wings/tail surface areas and so those remaining or settling in neutral possitions the plane would be a self-stabilizing glider.
I think a slight yaw to the left or right would be levelled out also by this. If it banks right the left wing would loose lift tilting the plane back to horizontal by the increased lift of the right wing. Those wing angels are designed for this effect to produce inherent stability. A induced banking by a slightly yawing plane would be eliminated by its inherent stability charistics I assume.
Just like the paperplane you mention which won’t be perfectly symmetric also but still follows a straight line and is able to land level and straight also due to its inherent stability.
@Oleksandr – The TV program regarding China Airlines 006 was on again last night. This incident occurred on a B747 so it might not apply to a B777 but, they lost power to one of its engines. The correct response to this is to shut off AP and then manually adjust the rudder before turning AP back on. This sequence is required because on this B747, the AP does not control the rudder. It is also possible that the AP controlled surfaces alone cannot compensate for the asymmetrical thrust. The B777 has TAC but the FCOM states that “the TAC does not fully compensate for the failed engine” and goes on to say, “following engine failure, the pilot can trim the airplane using additional rudder trim, control wheel input, aileron trim, or autopilot engagement.”
All of this suggests that without pilot input, a B777 might deviate from its course after the failure of just the first engine.
Buyerninety,
Re: “Ref Kate Tee; on the aircraft she saw, the cockpit windows were
visible, but there were no passenger windows. Given that 9M-MRO
had passenger windows, therefore it was not 9M-MRO.”
This is a wrong conclusion. If I recall correctly the size of a window is 27×38 cm. Can you see it at the distance of 3 km? Can you see an object of 0.3 mm size at 3 m distance (same angular size)? I guess no, unless you are a sniper. Now add mist on top of it.
Re: “Cables from the transmitter(s) to the antenna(s)”.
As you may know the main issue with a technical failure scenario is the absence of communication. All other issues have plausible explanations.
Re: oxygen tanks
It was actually noticed by Bruce if I recall correctly.
@Lauren H
” The B777 has TAC but the FCOM states that “the TAC does not fully compensate for the failed engine” ”
I don’t know what they meant by “does not fully compensate”.
This is may be instructive regarding the TAC;
http://proaviation.com.au/2014/04/01/a-boeing-777s-last-descent/
but you have to wonder if the simulator behaviour is backed up
by actual testing of a 777 (I mean the two engine off scenario,
not the full ‘take it to the end’ ocean impact scenario).
@Ge Rijn
I thought my post covered this previously, and I am unsure of
these WING ANGELS of yours, I think James T. might have seen one “At 20,000 Feet”, but now I’m going to bed as I find upon
reading too many of the posts on this page that I am more and
more having to bite my tongue and UGhhnn Ugnnn Ugnnnnn…
@Oleksandr
I am going to sleep, but you need to wake up. Think!
If she can see the cockpit windows, she can certainly see the
passenger windows (if they were there), and she stated they were
NOT there – referring to the area where the passenger windows
should have been, she said the “whole hull just appeared to be one plain surface”.
Since painting over windows doesn’t occur, then it was an airframe
without passenger windows, QED.
Did she say anything else to you that cancels her verbatim
statement I have quoted?
Interesting discussion about flight stability. I have experience in powered and unpowered flight. E.g. Flight instructor. Have studied aerodynamics. Engineer in Preliminary design at Boeing on various exotic programs.
Flight stability depends on the vehicle configuration and its mission. Example: A primary glider used for training purposes will be very stable in level flight. (No trim wheels, nothing to control stick forces except the original design.) E.g. I had students who initially could not control the aircraft in level gliding flight. We were all over the place with them in control. Most two seat gliders fly tandem, one pilot behind the other, student in front, instructor in back, thus the student cannot see what you are doing. I would tell them that I had the aircraft. They would let go of the controls. I would not take control. We both watched as the glider returned to stable level descending flight all by itself. The student would thank me for getting us to stable flight. I would confess reality. Nice test of an inherently stable aircraft.
The dihedral angle of the main wings, the center of lift and center of gravity of the design along with the tail lift and the rudder lift provide stability of a typical modern airplane.
As designs push the flight envelope they tend to become unstable designs. The shuttle is an unstable design. It cannot be flown without the computer control of the surfaces. The computers make rapid adjustments to the flight surfaces that cannot be done by the pilots. If the computers fail the shuttle goes unstable.
Fly by wire, by itself, does not affect the flight dynamics of an aircraft. It is just a way to reduce the weight and cost of the airplane.
Hydraulic design can affect the way an aircraft will respond to loss of hydraulic power. The affect should be as minimal as possible. Hydraulic power loss should allow the system to return to neutral control surfaces; if designed properly. Note: There are cases where poor design of hydraulics caused accidents.
The 777 is designed for inherent stability. The Dihedral angle in both wings and horizontal stabilizers, rudder large enough to provide directional control. How stable in un-powered flight, I don’t know. I would guess very stable. Always used power in 777 flight simulator. I would think the aircraft would glide, engines out, at a relevantly high speed, 200 – 250 kts, when in cruise configuration with a tendency for a slow heading change one way or the other influenced by updrafts and down drafts on the left or right of the aircraft and the lack of heading stability, e.g. it will drift right or left. Without autopilot this would continue until impact with the ground. (An engine out should cause the aircraft to turn away from the active engine until fuel starvation. A loss of altitude should also occur with increased glide slope.)
@Oleksandr, 09:27.”Then upon APU flameout, it would attempt to restart again.
In other words, could the plane be gliding for some time before 00:17, so that the login 00:19 corresponds to one more APU restart?”
I understand your aim. The APU will not restart because there will be no more residual fuel. What would replicate the 00:19 log-on, other than switching, would be the likes of someone shutting down the engines with fuel left at altitude then restarting for a powered ditching at low level, in preference for some reason to gliding down at idle; or maybe windmilling engines in a dive generating AC; or the APU starting after a damage less ditching (ie if not selected off before) etc. Maybe this has been all been through the mill before too but I agree that any final scenario has to be consistent with the 7th arc log on. Also, no ELT signal.
Lauren H,
Re: “It is also possible that the AP controlled surfaces alone cannot compensate for the asymmetrical thrust.”
I think it is a design requirement for any commercial aircraft: the rudder must be able to compensate asymmetric thrust.
But my interest is why the turn speed remained zero even after the flameout of the second engine, while bank angle did not. I mean Mike’s simulations.
@Oleksandr wrote “What is a chance for these cables to be simultaneously cut by debris or damaged in case of a blast/fire around EE-Bay area (I mean nose landing gear tire blast, oxygen tanks blast, flash fire, etc)? It appears that the area behind the cockpit is the most vulnerable.”
Always a chance.
The cockpit area and E/E bay area has many systems close together and thus is always an area of concern. Reducing the chance of multiple failures is part of the design requirements. Note: the area just below the tail at the aft of the fuselage is a pinch point for systems, similar to the cockpit / E/E bay area.
There is a lot of room in the overhead fuselage especially in twin aisle airplanes as compared to single aisle. So, many of the systems are routed in this area especially antenna cables because they will terminate on top of the fuselage; in general. For backup systems or secondary redundant systems they will take a similar path but be removed from the main systems path. Might separate systems by running on left and right side of overhead for redundancy. Belly makes sense for systems terminating at the bottom of the fuselage.
@BuyerNinety said:
“Subsequent to the report, Boeing issued Service Bulletin 777-35A0027 so 777 operators would be made aware of the need to fix this fault.
Unfortunate indeed, isn’t it, that the MAS maintenance record facility was damaged by a fire, so any records pertaining to whether this fault was fixed by MAS may no longer exist”
The FI states that this service bulletin was carried out on the aircraft:
“1.6.3.5 Airworthiness Directives
Maintenance and Inspection records provided by MAS indicate that at the time the aircraft 9M-MRO went missing, the aircraft and engines were fully compliant with all applicable Airworthiness Directives (AD). The most recent AD, which was accomplished on 17 Jan 2014, was FAA AD 2012-13-05 (Replacement of Low Pressure Oxygen hose).”
The workshop ‘fire’ was in the *avionics* workshop – a small internal (office-type) room where the avionics equipment was serviced / repaired – technicians sitting at desks.
It’s unlikely that this room would contain records of maintenance work carried out on other parts of the aircraft, and MAS is reported to have a centralised (computer-based) maintenance system.
The fire was very small (see pics on the web) and likely (?) a few pieces of paper or a piece of equipment that developed a fault. The after-the-fire pics available show office workers walking around the room with fire extinguishers – some smoke in the air but (as MAS stated) little/no damage to the room.
Oleksandr. In my 1.33 between damage less and ditching insert “powered”.
I hate to bring this up but I just can’t get my mind around this suicide scenario.
Suicide itself – OK, plenty of examples of that – but this method. Steal an airplane, murder hundreds of people, cut communications and fly for hours into the night, carefully land the plane at sea so as to ‘hide’ it (at best a very risky objective) and after all that where is he – possibly still alive and still must end his own life. How? He should have taken cues from Silk Air, German Wings or Egypt Air – take control of the plane and dive.
The motivations to hide the plane and for this protracted process escape me. Who needs 7 hours alone to contemplate a self inflicted fate? As we know it is always convenient to blame the dead pilot in the case of an air crash – but this???
Probably this has been addressed somewhere in the annals of this blog – but I could not find it. Perhaps I am the only one confused.
Some reasons that the TAC does not fully compensate for the failed engine:
The thrust asymmetry compensation system operates automatically if a thrust asymmetry condition is detected. It continually determines the thrust of both engines from a look-up table that presents engine thrust as a function of engine parameters and flight conditions (e.g. EPR, altitude, outside air temperature, and airspeed). When the thrust asymmetry exceeds a certain amount (10% IIRC), it calculates the rudder trim required to balance it. Since the actual thrust may differ slightly from that resulting from the look-up table, the compensation is approximate. The compensation is not limited to the failure of an engine, but is adjusted to the calculated momentary asymmetry between the two engines, based on the measured engine parameters. So if the thrust of the second engine reduces, the compensation reduces also.
The TAC operates only on the rudder trim. Application of rudder to balance a thrust asymmetry also requires application of ailerons, but that is not provided by the TAC.
When the autopilot is engaged, it will supply any rudder and aileron that is not provided by the TAC.