Malaysian Airlines MH370 contact lost

[USAF1956]

If the US or another country had a SOSUS (or similar) system near there, wouldn't it be possible to listen for an anomaly that could be the plane impacting the water. This would more or less confirm the plane crashed into the ocean.

[onetrack]

I am still amazed that no-one in authority appears to have mentioned checking seismic recording equipment. A couple of previous posters here have mentioned it.
Seismic equipment can throw up a record of the tiniest earth tremor - and 200+ tonnes of aircraft hitting land or water at 500, 600, or 800kmh must have produced a measurable shock wave (if it has crashed, as we must presume, is the more likely scenario).

Maybe the only way there would be little shock wave is if the aircraft stalled and flew into the water nearly level, a-la AF447, at just over 200kmh.
In which case, surely there would be a pile of floating debris? 10% of the B777 construction is composite, I've been informed, so would that style of composite float? Seating, bodies, carry-on luggage, a lot must float for days?

[Dress]

Malaysia ask for radar data from some neighboring countries.


http://i.imgur.com/TpbYREZ.jpg

[NamelessWonder]

@MartinM
This means that the Air Forces in the region are operating like Swiss Air Force these days. 8am in the morning to 6pm in the evening.

Minus 2 hours for lunch, of course . . . at least in the case of the Swiss ... but you know that already!

@Luke Sky Toddler
Still confusion about this so let's put it to bed, I was flying and on the same frequency at the time, Ho Chi Minh ATC started going mad trying to contact the MH370 on 121.5 at around 00.30 local Vietnam time. That is 01.30 Malaysia time, 1730 Z.

First-hand information - hallelujah! Many thanks

@Etudiant
Re the fuel load, it was stated very early in this event that the aircraft had 7 and a half hours of fuel loaded. So there was plenty of gas to go even further than the 4 hours post loss of contact.

No, it was stated that it most likely had around 7 and a half hours fuel - not the same thing at all!

Harping back to the point I made goodness knows how many pages ago, but last night my time, whilst I recognise the limitations of FR24 and the like, there are 3 transponder anomalies (as previously stated) that show up in the 90 minutes or so of interest and also in the local area.

They just happen to affect ONLY MAS370 and 2 of the aircraft nearest to it (though UA895 appears to be unaffected)

KAL672 as it passed 105.2 East at 16.55 UTC
CCA970 as it passed 105.25 East at 17.02 UTC
MAS370 as it passed 103.6 East at 17.21 UTC

This begs the question what else was in the area, perhaps travelling NW-ish at the time that had the capability to, and may have affected all 3 transponders AND ONLY THOSE THREE

Perhaps the illustrious Electronic Warfare ship that is now "assisting" with the search and whose Govt are not exactly fans of the Chinese (who themselves are in a very good position to sink the fiat dollar)?

Or should we only consider possibilities that point to Eastern and/or Muslim countries?

Perhaps nothing at all, perhaps not.

[Lost in Saigon]

Mode A/C only sends the numbers you set.
Mode S (and ADS-B) also has the airplane ID and AFAIK that is not readily changed in flight.

EDIT: maybe not. Apparently some CAN change the airplane ID from the cockpit.
Anyone know if the 777 can do this?



Of course you can change your aircraft ID (call sign) in the cockpit. The call sign is your flight number as in "MH 370". This changes for each flight and is not specific to any one aircraft.

I think this only applies to ADS B or CPDLC where the crew enters the flight number for the particular flight in the Flight Management Computer.

Non ADS B flights would have the Call Sign entered by ATC when they assign the transponder code for the flight.

(please correct me if this information is not correct)

[ploughman67]

I'm a current B777 pilot.

About a year ago, in response to a Boeing Flight Crew Ops Manual Bulletin (BAB-95) relating to a potential software glitch affecting the selected altitude on the MCP, the operator I fly for changed our procedures to comply. Before the change we used to leave the Altitude increment selector in the 1000s position, subsequent to the change it is now routinely left in the Auto position (i.e 100 foot increments).

Had the flight crew experienced a rapid decompression then following donning of oxygen masks, establishing comms between the two of them, checking for cabin altitude/rate and passenger oxygen as required the next checklist item calls for an emergency descent. In my company this is routinely taught as a double loop starting with selecting a lower altitude on the MCP altitude selector, optionally using HDG/TRK SEL to turn off the airway, pressing the FL CH switch (commence descent at current IAS), deploying the speedbrake and ensuring the thrust levers are closed. Once the descent is established a second sweep tidies up the altitude selected (MSA/10k'), refines the heading, increases speed if appropriate and checks again for speedbrake deployment and thrust lever closure.

If there had been an explosive decompression centred on the E&E bay that knocked out all comms equipment and the crew oxygen could it be that the initial actions of the emergency descent checklist, the first sweep, be accomplished then hypoxia set in before the second sweep could be completed?

Under the old 1000s position of the ALT SEL an anticlockwise spin would reduce the selected altitude by many thousands of feet, an anticlockwise spin of the heading could give a large heading change to the west, the aircraft would descend at current IAS (normally in the cruise at FL350 M.84 equates to 250-260Kts indicated). However if the ALT SEL was in the Auto position a quick spin would change the selected altitude by only several hundreds of feet, possibly by pure chance FL295?

This scenario could explain the lack of comms, the primary radar target tracked on a westerly routing and the fact that no debris has yet been found. At FL295 the pilots would succumb quickly to the effects of hypoxia, the passengers likewise once the passenger oxygen was depleted. The cabin crew may have transferred to portable oxygen and attempted to reach the flight deck (my company trains the cabin crew to do exactly that if the descent has not commenced within 80 seconds). However even had the cabin crew entered the flight deck would (could?) they attempt a radio call, once they removed their mask there wouldn't be much time of useful consciousness to get that call out even assuming they knew how to.

If I had access to satellite imagery I think I might extend the search out in the last presumed direction of flight to the fuel exhaustion point and see if anything was there.

Possible? Plausible?

[awblain]

I hope someone is doing a carefully controlled sonar survey of the area where contact was originally lost.

The problem is the sea between Thailand, Vietnam and Malaysia is like a puddle. It's extremely shallow, about 200 feet deep, and likely full of junk already. You can't easily use sonar. If no-one finds any debris soon, then the wreckage is probably going to be found accidentally in the end by being snagged by a fishing net.

It might also still have been moving fast enough on impact in shallow water that it embedded itself in the mud on the sea bed, muffling any pingers.

Without better inferred positions from radar and radio transmission records, the search for the wreckage may be a long one.

[awblain]

ploughman,

How would the cabin crew get into the flight deck to bring the oxygen if the occupants were unconscious as their oxygen was out. Is there no backup oxygen carried in the cockpit in case a crew mask fails?

Surely the whole point of new locked doors is that you're not able to break in, and so someone would have to admit the cabin crew with their bottle. A flaw in this back up plan?

[Surely]

You have to explain the total lack of any form of communication from the aircraft past the point of known contact.

Do these theories of total comms blackout but still flight capable aircraft hold any water.

[USAF1956]

There is an extensive SOSUS sytem in that area that would have detected a noise of that magnitude,

[WingNut60]

I offer my apologies if this has been mentioned before, but I may have missed one or two of the plethora of theories ..... but considering the phase of the flight, would a galley fire not be a possibility?

I know not the implications regarding loss of comms.
Maybe someone can tell me.

[Lonewolf_50]

USAF1956
1. If the US or another country had a SOSUS (or similar) system near there, wouldn't it be possible to listen for an anomaly that could be the plane impacting the water.
2. There is an extensive SOSUS sytem in that area that would have detected a noise of that magnitude, FWIW, SOSUS (https://www.fas.org/irp/program/collect/sosus.htm) was/is mostly a deep water system, not a good fit for the comparatively shallow water of the South China Sea. Beyond that, were there some hydrophone array in the area, a surface anomaly (short duration acoustic event) may or may not reach a given hydrophone due to the varied paths sound takes and the high ambient noise in that region. My estimate (very out of date, been some years since I did real ASW) is that there is no such hydrophone array in that region.

Hoping that SOSUS could give a datum for this search seems low to zero probability.

[OldDutchGuy]

Old Boeing Driver asks is there is anything else to add, past that the A/C took off and contact was lost. Yes, there is. We know it took off, we know it had a competent flight crew, we know it had lots of fuel, we know it climbed to altitude, and we know it was on its intended course.

We can reasonably conclude that the A/C was on autopilot. These guys are not likely to be hand-flying that thing in the gloom of night on a long-haul.

We also know that vast amounts of assets are out looking at the water surface. Plus, lots of small boats out there, fishermen, diesel-fuel tankers, junks, coastal freighters, all kinds of stuff. We know that an aircraft impacting water is going to bust up into a vast number of parts, and a lot of those will float around. Yet, nothing is found.

That tells us that it is not where everybody is looking. So: where is it? Getting past murky reports of radar contacts in other places at different altitudes, you do have to conclude that the more logical flight path is the one the autopilot has it set on. That A/C heads North - to land. From that inference, either the A/C continues onward on that autopilot until it runs out of fuel, then crashes, or the autopilot is interrupted and the A/C goes into an uncontrolled descent and impacts terrain. We have learned that an impact into terrain at high speed will leave a small crater - in the case of United 93, only 30 feet across. Are you going to spot an impact crater in the jungle of Southeast Asia? Or does the jungle simply swallow it up?

In which case, you may never find it. Ever. Hard for us to appreciate, with our fascination with technology, yet still quite plausible.

[The Ancient Geek]

Two comments -

RR engine data :
Given the vagaries of HF radio propagation it is entirely possible for Fort Meade to have received signals which did not arrive at RR. A simple issue of antennas in different locations. In any event I would not expect RR to make any public comment for contractual reasons.

Cockpit windshield failure :
This is a possible cause which we have not considered. Such events are rare but they have happened. This would cause explosive cockpit decompression and incapacitation of almost certainly at least one pilot.
With the captain incapacitated and the FO probably injured the shock and startle effect would leave a less experienced FO with a serious workload problem.

[Sober Lark]

@ Dai Farr 'I flew SAR on Air India 182 back in 1985'


The return on that aircraft vanished at 07.13GMT. An emergency was declared at 07.30GMT and SAR found floating debris at 09.13 GMT just over 120 miles off shore. The technology they had back then was primitive compared to today, yet wreckage location only took a matter of hours.


A mid air disintegration leaves sizable floating wreckage and later washed-up debris. From my involvement the problem with the smaller washed-up debris was the general public didn't recognise them as belonging to an aircraft.

[Dress]

NASA Joins Hunt for Missing Jetliner | Space.com (http://www.space.com/25046-nasa-missing-airliner-flight-370.html?cmpid=514648_20140313_19997324)

NASA Joins Hunt for Missing Malaysian Jetliner

[Force For Good]

It seems to me that while terrorism, unlawful interference, deliberate action or a government cover up of some kind are not confirmed as being completely impossible, they can’t be far off, especially given the time that has passed without any proper clues of that nature. I will admit that the Malaysia’s Command and Control of the incident so far has aroused suspicion as has the lack of a cargo report. But as many have said, the most obvious and logical causes are probably the most likely.

That gives us two scenarios.

Either the aircraft went down at the same time as comms was lost (01:21 ish) or it continued to fly for a duration (up to a maximum of 5-7 hours given fuel discussions) in a given direction.

That puts the aircraft in a number of possible locations.

In the vicinity of last comms, in the South China Sea between NE Malaysia (peninsula) and SW Vietnam. This becomes less likely every day, assuming that the search is being conducted effectively.

If it did make the possible turn back towards Malaysia, then it could therefore be on mountainous, densely forested land, or again out to sea in the Malacca Strait, Andaman Sea or even Indian Ocean.

It could also be further into the South China Sea than we think, if the turn back was radar error.

The lack of a debris field found to this point suggests that either it’s much smaller than we expect (high velocity impact in one piece, successful ditching followed by aircraft sinking, shallow dive after fuel supply exhausted) or it isn’t where we expect (flown a full 7 hours towards the un-searched Indian Ocean for example).

So far, I think the most logical explanations all include hypoxia in some form, which can easily reduce a highly functioning individual to utterly useless in 90 seconds.While I cling to the hope that at least some of those on board MH370 could still be floating on yellow rafts with a dwindling supply of airline food, I take some comfort in knowing that drifting away through the delirium and hilarity of hypoxia must be one of the most painless and peaceful ways to go, particularly in an aircraft accident.

This leaves me with questions still:

Why are land based searches not being conducted in remote and forested areas? :confused:

Why are more countries not being asked to support? Malaysia and China between them have plenty of allies with superior military capabilities which could be put to excellent effect in solving this mystery, or even locating some survivors! :ugh:

[clearedtocross]

AFAIK the aircraft identity is not coded into the transponder. ATC enters the aircraft ident into their system when they assign the transponder code. I would expect that if you select the same code it would cause problems with ATC.

Now if you were to coordinate with another known flight in the area and have them turn off their transponder as you turn yours on with the same code, that would be seamless with ATC.

That is not true (or inaccurate, as the guys in the pc would say). Each mode S transponder is set up before installation with a worldwide unique 24 bit adress obtained from a global registration. You cannot change this adress in flight. The adress is tied to the aircraft registration. The only codes that can be assigned or re-assigned is the call sign and the 4 digit octal transponder code.
Same 24-bit aircraft adress applies to 406 Mhz ELT broadcast.

[OleOle]

Thanks

What would happen in your scenario to the speedbrakes and thrust setting when the selected altitude is reached and the pilots already unconscious ?

I see the main problem with this hypotheses that only transponder and acars comm equipment would have to be knocked out but all other vital electronics still working. On the other hand what happened on MH370 surely wasn't an everyday event.

BTW:It doesn't really matter but as far as I understand the 29.5 k feet was derived from that unidentified primary radar contact. Precision of that height would depend very much on angular resolution of the primary radar, so I guess it is just a best estimate give or take some 1000? feet.

[gear lever]

Surely....

Exactly!

There are too many theories on here that just dont hold water.

Whatever people theorise happened i.e. O2 bottles exploding, decompression, skin failure, terrorists, onboard fire, bomb etc. etc. just does not fit with the lack of wreckage (small debris field/ straight down entry into water?), lack of comms, lack of transponder, aircraft did not continue flying on A/P etc.

It's staring us in the face and it is not pretty.

[LiveryMan]

Cockpit windshield failure :
This is a possible cause which we have not considered. Such events are rare but they have happened. This would cause explosive cockpit decompression and incapacitation of almost certainly at least one pilot.
With the captain incapacitated and the FO probably injured the shock and startle effect would leave a less experienced FO with a serious workload problem.

Doesn't explain the transponder ceasing all transmissions.

[Dress]

US Officials Believe Missing Plane Crashed in Indian Ocean

US Officials Believe Malaysia Airline Crashed into Indian Ocean - ABC News (http://abcnews.go.com/m/story?id=22894802&ref=http%3A%2F%2Ft.co%2FuPTMYNU5Z1)

[Uncle Fred]

Dia Farr - Very good info in your post--thanks for being one of those who keeping this thread worth reading. Rather good to see some wheat amonst the chaff. Awblain and Lonewolf also adding good ASW/SAR bits in as well.

Ploughman, I also fly the 777 and you made a point that I think most, if not all of us have missed--and that is problems with the MCP. How many times have we either done it ourselves or seen it happen when the altitude is spun incorrectly or the heading knob (or vice versa) is spun when it was meant to set a new altitude.

These errors are of course normally quickly caught and so no harm no foul...but add in hypoxia and and now we are talking about how this little bit of MCP confusion could lead to bigger problems.

My carrier still keeps the alt selector in auto unless flying a NPA but I can see why yours has changed the procedure.

One little knob, one little twist, one bit of confusion growing ever larger due to hypoxia and suddenly the MCP could be THE major player.

Glad to see the thread this morning with some good info being posted.

[island_airphoto]

RE Mode S:
It has a code you can enter for that flight, but also a code in the background unique to the airframe. It is - in computer terms - a MAC address and is used like that for data communications in the background.

There are 24 bits in the ICAO mode S address. The USA is assigned a block of codes starting with Axxxxx, where A is the first Hexadecimal digit and xxxxx are 5 Hexadecimal digits unique to the aircraft.

Does the 777 let the pilots change the tail number as well as the flight ID?

[captplaystation]

ploughman,

a very plausible scenario, the MCP is indeed a very obvious gotcha

awblain,

don't worry, if they need to the CC can get in, if no-one is awake to "deny" them.

[CodyBlade]

Some of the Qs and As are getting abit too detailed and specific and could/can be used by 'others' for sinister motives.

[Old Boeing Driver]

I flew with some older FMS's for awhile, and a controller asked about our tail number, which was being transmitted as another ID.

We looked in the FMS, and sure enough, the previous tail number was still in the box.

We were able to change it from the cockpit, although we were on the ground when we did it. I don't know if that would make a difference.

The FMS did talk to the transponder.

Also, ATC doesn't see the tail number for an airliner. Just flight number and airline code

[BlueConcorde]

Guys and gals, did the Indonesian Air Force make any announcements on the MH370??

I find extremely disturbing that a radar primary plot crossed the whole Malaysia heading west to Indonesia and Malaysia didn't send a fighter to check. And find even weirder that the plot disappears very close to the airspace boundary between Malaysia and Indonesia (Pulau Perak).

Digital Globe could release images of the region close to oil rig and debris field seen by CX crew, and also the Malacca Strait...

Definitely the Malaysian military are hiding something, but not some info that would help out finding the aircraft right now, but their own incompetence on letting an unknown radar plot cross the country and do nothing about it.

[FE Hoppy]

MODE S and ADSB transmit as part of the extended squitter the airframes unique ICAO 24bit address.

It is hard coded and cannot be changed.

[brika]

Indonesian Air Force Boeing A7303 combed the Malaka Strait in search of the missing Malaysia Airlines (MAS) MH370 from Monday (March 10) to Tuesday, but in vain.

[Old Boeing Driver]

I still think the, "What was in the cargo", is a very valid question.

[Hornbill88]

I still think the, "What was in the cargo", is a very valid question.

If any journalists are reading this, perhaps you could raise it at tomorrow's press conference

[marconiphone]

The BBC has clearly lost the editorial plot.

They just had an interview on BBC World TV with some conspiracy theorist nutter spouting a mixture of inaccurate and discredited tosh, complaining about SAR incompetence and a lack of information. There must be pushing 100 multinational ships and aircraft out there searching, not to mention all the electronic scrutiny. Are they all incompetent? What sort of information does he want? Fabricated 'facts' just to keep him and the media happy?

The whole semi-frivolous tone of the interview, anchored by Lucy Hockings (promoting the 'someone's holding something back' line), was pretty distasteful in the circumstances.

[shawk]

If both pilots were unconscious due to hypoxia, does this mean that the flight deck oxygen masks were fed from a single, common source?

[Keef]

AFAIK the aircraft identity is not coded into the transponder. ATC enters the aircraft ident into their system when they assign the transponder code.

Wrong. The aircraft identity is coded into a Mode S transponder and cannot be changed. The Flight ID is separate and under the control of the crew, as is the squawk.

If you look at the registration record for any aircraft, you will see something like:
ICAO 24 bit aircraft address:Binary: 0100_00_000_000_01_0010110100
Hex: 4004B4
Octal: 20002264

Which will link back to the specific aircraft, whatever Flight ID or squawk is selected.

If you look at the full Mode S return on a screen, you will see the "4004B4" displayed.

Back to (bemused) watching brief.

[GlueBall]

Making a cell phone call in a jet flying over 8000 ft is virtually impossible...and data exchange impossible above 8000 ft.

Stormy Knight . . .
As for cell phones and aircraft (yet again), hands up all those who have flown between say western europe and the far east and never, ever found the likes of a "welcome to CIS telecom" ( or something similar) text on their phone on arrival in NRT....

Just for a factual record: My cellphone, unintentionally left ON, inside my luggage stowed in the forward section of B747 main deck, had recorded 3 "welcome messages" from a Bangladesh telecom, while traversing the country at FL330. :ooh:

[mixduptransistor]

My apologies if this has already been discussed, this thread is huge and moving fast.

What about the report in the WSJ this morning about the engines reporting back that they ran for four hours? How is that possible?

I'm curious as to all the various radios on the plane, their locations, and what they are talking to. Do the engines have a completely independent radio that would be located somewhere other than the main electronics bay? Is it possible for the aircraft to go completely radio silent but still report back engine telemetry? Does that system talk to a satellite?

I've heard that harped on all morning on the radio and TV news here in the US and no one is asking those very obvious questions....how that would continue to work but literally no other data is coming off of the plane.

[Kerosene Kraut]

The SecDef of Malaysia denied the engine data transmission story today. The US still seems to support some ongoing flight theory.

ABC news:
http://abcnews.go.com/International/us-officials-malaysia-airline-crashed-indian-ocean/story?id=22894802

[brika]

The theory of MH370 continuing to fly a further 4 to 5 hours after last point of contact appears to be weakening -

Malaysian authorities have said reports that the missing Malaysia Airlines flight MH370 may have flown for an additional four hours beyond its last sighting are inaccurate, and that the final information received from its engines indicated everything was operating normally.

"We have contacted both the possible sources of data – Rolls-Royce and Boeing – and both have said they did not receive data beyond 1.07am," Malaysia Airlines chief executive, Ahmad Jauhari Yahyain, told reporters on Thursday afternoon. "The last transmission at 1.07am stated that everything was operating normally."

Thursday 13 March 2014 12.30 GMT - The Guardian.com

[ex-EGLL]

Wrong. The aircraft identity is coded into a Mode S transponder and cannot be changed. The Flight ID is separate and under the control of the crew, as is the squawk.

If you look at the registration record for any aircraft, you will see something like:
ICAO 24 bit aircraft address:Binary: 0100_00_000_000_01_0010110100
Hex: 4004B4
Octal: 20002264

Which will link back to the specific aircraft, whatever Flight ID or squawk is selected.

If you look at the full Mode S return on a screen, you will see the "4004B4" displayed.

The use of the word transponder is causing confusion here. There is the Mode S transponder referred to above, there is also the Mode A/C transponder which is the 4 digit SSR transponder.

[1001001]

FNG here. Private Pilot and aircraft owner-PA-28. It is good to see that there are some real experienced folks here, adding good info and not just crazy conspiracy theories.

As for transponders, every aircraft registered, at least in the USA, has a unique transponder address assigned, whether a xpdr is installed or not. For instance, my PA28 has a Mode C transponder, which as far as I know does not broadcast any identifying info other than whatever code I have dialed into it. AFAIK the address code is reserved for future use. Of course in the airline and commercial world where more sophisticated xpdrs are required (and soon for GA too, with the impending ADS-B requirements), the address is coded in and transmitted on the extended squitter.

As far as simming goes, at least in the GA world I hear it is getting quite popular as a tool to maintain skills when one can't fly as often as one would like. My CFII has said he uses FSX as a tool to brush up on instrument procedures, and recommends it to his students. I personally fly XPlane 10 a lot to keep up when the weather keeps me grounded (still working on my inst rating and of course a PA-28 is not certified for flight into known icing). Simming is a tool that I would bet a lot of commercial and ATP pilots use for fun and informal training, nothing inherently suspicious there.

[OPENDOOR]

ex-EGLL;
The use of the word transponder is causing confusion here. There is the Mode S transponder referred to above, there is also the Mode A/C transponder which is the 4 digit SSR transponder.

Does the T7 have both?

[andrasz]

A number of posts suggested that all those dense jungles in SE Asia could easily hide a small smoking hole. Let me remind everyone that the romantic picture of dense jungles (with aeroplane wrecks overgrown with trees waiting for Indy) is a thing of the past. The region has one of the highest population densities of the world, and more than 90% of the original primary forest cover is gone, to be replaced by farmland, palm oil plantations, and second-growth forests after logging. Even in mountainous areas where the forest canopy appears continuous, there is a dense pattern of small farms and villages. I find it inconceivable that a T7 could have landed or crashed anywhere on any land within range (except small uninhabited islands in the Pacific and Indian Oceans, but those are not many) without being heard or seen by somebody.

[bono]

Kerosene Kraut:

The SecDef of Malaysia denied the engine data transmission story today. The US still seems to support some ongoing flight theory.

Its not that Malaysians are against the ongoing flight theory, till someone locates the debris field you have no option but to assume that the aircraft flew beyond that geographic area. Right now they are scouring Malacca strait and eastern Andaman Sea. In next couple of days they will move further west into the Bay of Bengal and Indian Ocean. Its pretty obvious by now that the debris field is not anywhere close to main shipping channels in the Indian ocean but perhaps further north in the Bay of Bengal.

[SaturnV]

According to ABC's chief Pentagon correspondent, the U.S. is sending the USS Kidd from the Andaman Sea west into the Indian Ocean, and it will take the ship 24 hours to get to the area where the U.S. thinks the plane might be.. Cruising speed could be 33 knots.

[snakepit]

For the rapid decompression theorists here are some facts from RAF AVMED.

Hypoxia (anoxia) occurs when the body is short of oxygen.

Amount of oxyhaemoglobin in the blood depends on the amount of oxygen in the lungs (not atmosphere).

Partial Pressure of Oxygen

At sea level the standard atmospheric pressure is 760 mmHg. 21% of 760 will be from Oxygen because amount of oxygen in the air is 21%. Thus partial pressure of oxygen in the atmosphere at sea level is 160 mmHg. The amount of oxygen in the air can be described as its partial pressure in mmHg. As altitude increases the partial pressure of oxygen in the atmosphere falls. The rate of change of pressure is greatest as we climb from sea level and decreases with altitude.

At sea level, percentage of oxygen in the lungs is only 14.5% (in atmosphere it is about 21%). Thus the partial pressure of O2 in the lungs is 100 mmHg.

As altitude increases the partial pressure of oxygen in the atmosphere falls but the proportion of oxygen in the atmosphere remains the same. Also as altitude increases the partial pressure of water vapour and to an extent carbon dioxide in the lungs remains the same reducing the partial pressure of oxygen in the lungs still further. Reduction in cabin pressure to an equivalent altitude of 8000 ft (65 mmHg partial pressure of O2 in lungs) produces a detectable impairment of mental performance. Healthy people are able to compensate for altitudes up to 10,000 to 12,000 ft. Above this, risks become serious. Short term memory is affected early on.

At 18,000 ft the partial pressure is 50 mmHG (half that at sea level).

Unconsciousness occurs at about 35 mmHg of oxygen in the lungs (equivalent to prolonged exposure to altitudes between 20,000 and 25,0000).

Air can be used up to 10,000 ft. After that it needs to be mixed with oxygen up to 33,700 ft. Above this 100% oxygen upto 40,000 ft.

Above 40,000 ft 100% oxygen alone is insufficient and it must be supplied under pressure to the oxygen mask. This is pressure breathing.

Hypoxia does not lead to shortage of breath. If the oxygen supply system fails the normal reaction to lack of oxygen, "Panting" does not appear because, there is no excess of carbon dioxide.

Onset of hypoxia is insidious (like CO poisoning) and can be recognised only by being very aware of the symptoms.

Symptoms of Hypoxia:

Concentration difficulties.
Impaired judgement, mood changes, euphoria (euphoria can be experienced above 10,000 ft).
Drowsiness and lethargy.
Light headedness, dizziness, nausea.
Loss of muscular co-ordination.
Pallor and cyanosis.
Failure of the basic senses, especially colour vision, which becomes affected by 8000 ft. Night vision affected above 8000 ft.
Unconsciousness, coma and death.

Following factors increase the onset of hypoxia:

Exercise
Cold
Illness/age
Fatigue
The use of drugs/alcohol
Smoking. It can raise the physiological altitude by 4-5 thousand feet above the actual cabin altitude as the ability to transfer oxygen is reduced by 4% to 10%.

Time of Useful Consciousness

It is the length of time during which an individual can act with both mental and physical efficiency and alertness. It is measured from the moment at which an individual is exposed to hypoxia. It varies with altitude and these are the relevant levels believed to apply in this case

Altitude in ft .......... Time

30,000 .................. 30 seconds to 1 minute

35,000 .................. 15 to 30 seconds


Time of useful consciousness for people doing light to moderate work (effective performance time) falls by 40%.

Time of useful consciousness for people already short of oxygen (flying at a cabin altitude of 8000 ft) are half of the above values.

Can any 777 pilots confirm the cabin px at cruise altitude of 35,000ft? I know from my time as an FE that in many aircraft it's in the order of 5000 to 8000 ft so even before a failure all occupants are partially suffering from hypoxia.

Not a theory just some facts to help the discussion along.

[paddylaz]

Pentagon have just told ABC News that they are of the opinion mh370 went down in the Indian Ocean.

They are so confident that they are repositioning USS Kidd to the area to start a search

[hefy_jefy]

I believe that in the case of Swissair 111 the range of the acoustic pinger was reduced due to being deeply embedded in the debris, the entire aircraft was in very small area.
BTW The idea of a check of local Seismic records sounds like a good one.

[JRBarrett]

Of course you can change your aircraft ID (call sign) in the cockpit. The call sign is your flight number as in "MH 370". This changes for each flight and is not specific to any one aircraft. I think this only applies to ADS B or CPDLC where the crew enters the flight number for the particular flight in the Flight Management Computer. Non ADS B flights would have the Call Sign entered by ATC when they assign the transponder code for the flight. (please correct me if this information is not correct)

The FlightID can be selected/changed in the cockpit via the radio management unit, FMS or by a dedicated control head - depending on the aircraft model. Part 121 operators typically set this to the flight number of the specific scheduled flight.

The mode S ID however can NOT be changed by the flight crew. This is a unique 24-bit number derived from the aircraft's registration number, and is hard-wired into the transponder mounting rack. Changing it (typically) involves moving wire jumpers on a programming plug, and can only be done on the ground by maintenance engineers.

The mode S ID is hard-wired in this way so that if the transponder has to be changed, the replacement unit will automatically assume the correct ID, merely by being slid into its mounting tray.

[Fly26]

Could I just ask if anyone knows or has any experience in what level of equipment is being used to sweep the seabed? I presume the search teams are scanning the sea floor for debris and not just concentrating on the surface? It's not the deepest water in the world. Can under water devices cover a large area or is it a slow process to search an area in detail enough to detect parts of aircraft? I'm starting to wonder if any things been missed, particularly in the vicinity of the last known position.

[LASJayhawk]

To answer a question posted earlier, No there is not a separate A/C transponder. The mode S boxes transmit A C and S.

There are 2 strapping modules in the avionics bay that hard code the aircrafts registration number for the transponders.

[OPENDOOR]

snakepit;

At sea level the standard atmospheric pressure is 760 mmHg.

Thank God altimeters are not calibrated in mmHg, I had enough trouble changing from 1013.25 to 29.92:O

[highflyer40]

Malaysian official said they contacted rolls Royce and Boeing and both said their data stopped at same time as Malaysians... that should put a stop to the 4 hour engine data saga, there is no way that both those companies would keep quiet if someone else was telling porkies about their companies!!

[PlainSailing1]

If you sift through the signals of the past 6 days, and discard the obvious chaff, you'll see hints of where in the haystack the needle is most likely to be found.
Yes but it would be a good idea if someone could first find the 'haystack'

[Sanibelsland]

What type of "indications" would they be referring to that no one else was able to obtain.


Reuters Top News ‏@Reuters (https://twitter.com/Reuters) 4m (https://twitter.com/Reuters/status/444156014141526016)
Satellites picked up electronic ping from Malaysian flight MH370 after it lost contact with ground control: source close to investigation


Was this not already discussed as not being a confirmed report?

[Greenlights]

A resume of the research :

"here
no there
it went eastbound
no no westbound
oh here some fuel trace
no no, it's from a boat
arfff
oh here some debris!
no no it's not
it was on its route
no no it flew off route
let's search on the west side
oh here a raft
no it's not
oh! here a debris 18/20m
no no it's a joke by chinese
arrff
let's go to Indonesia then."

:ugh::ugh::ugh:

[EEngr]

Fly26 (http://www.pprune.org/members/372021-fly26):
what level of equipment is being used to sweep the seabed?

Basically, two things. They are listening for the flight recorder sonar pinger and also using active sonar, including side scan.

One problem with sonar is that the coverage tends to be fan shaped. The deeper the water, the broader a path they can cover on the bottom. The waters where contact was lost aren't very deep. So the strips of bottom covered per pass won't be very wide. On the positive side, the nature of the sea in the search area rules out things like thermoclines and other phenomena that could blind sonar.

If by some chance MH370 made it East to the Philippines or West of Sumatra, there are some deep drenches and rougher bottom terrain to deal with.

[LASJayhawk]

406 ELTs send out a test message for 45 seconds before they go into the crash mode and trigger alarms. It IS possible that the ELT went off for a few seconds before it became separated from its antenna. That test signal might be logged somewhere

It's a hope anyway. At this point the only thing I know for sure is that it is not at KBVU.

[cynar]

This is a big scoop for ABC news. Author is Martha Raddatz, absolutely impeccable sources and credentials, great, seasoned reporter.

What's becoming clear to me is that the U.S. (Pentagon and NTSB at very least) have better intel than the Malaysians, and, to protect the extent and sources of such data for reasons of national security and international relations, have had to find back-channel ways (the NTSB radar "advisors," NASA, etc) to leak the correct location of the aircraft to the Malaysians so as to seem to have them organically find it.

Unfortunately, with Vietnam etc. making good-faith efforts and taxing resources in a humanitarian gesture, the U.S. can't wait, sources are leaking to hurry this up. You can bet that was okayed at the highest levels and we have been talking to China.

My current theory is that the plane was hijacked but that the pilot flew it out into the ocean rather than to the specified destination.

This also helps explain why Greg Feith, well-respected former NTSB investigator, was on air recently floating the turn-back/hijack scenario. At the time I thought he'd lost his bearings in all the media hype. Maybe more likely he had inside info.

http://www.nbcnews.com/storyline/missing-jet/crash-expert-malaysia-jet-probe-will-become-criminal-inquiry-n51036

[flt001]

US Officials Have 'Indication' Malaysia Airline Crashed into Indian Ocean - ABC News

Tom Costello, NBC, is saying USS Kidd is heading to the Strait of Malacca NOT the Indian Ocean.

So we have two main media sources saying different things...again. Perhaps everyone needs to just slow down a bit. Chaotic information releases.

[Lonewolf_50]

RG:
From what an airline source/Malaysia press conference previously released:

(1) They do not appear to have the sattelite option for ACARS, using the VHF option instead.
(2) They apparently did not exercise the "Boeing tracks our ACARS" option in their support contract with Boeing.

Some pages back, a PPRuNer provided a map with a series of notional, overlapping VHF range circles (http://www.pprune.org/rumours-news/535538-malaysian-airlines-mh370-contact-lost-136.html#post8371554)and ground station locations to give an idea of where you would expect to see ACARS(VHF) be able to receive data from an aircraft in flight at cruise altitudes. You can see that there is a bit of a gap west of Thailand. IF, as also discussed in this thread, the RR data system only sends info when something changes, as opposed to "every x number of minutes," then it is very plausible that no message was sent until the plane was in that gap, IF that gap is where it ended up. As you can see, there is a lot of "IF" going on there.

Beyond that, no comment on why Uncle Sam thinks the bird went down in the IO.

[barrel_owl]

Malaysian official said they contacted rolls Royce and Boeing and both said their data stopped at same time as Malaysians... that should put a stop to the 4 hour engine data saga, there is no way that both those companies would keep quiet if someone else was telling porkies about their companies!!
Wait. Two questions.
First. Can you please provide a link for this information?

And second. Then why is the aircraft being searched on Indian Ocean? How can the ACARS datalink have stopped at the same time as the aircraft went off radar and the same aircraft have flown hundreds of miles West without transmitting any downlink?

Would someone please care to explain?

[mabuhay_2000]

There have been so many leaks, which have then been dismissed by the Malaysians, that it's easy to start taking a pinch of salt with every new tidbit that pops up. Even so-called reliable media sources have seen their sources dismissed.

So what, if anything, do the US know that led them to redeploy the Kidd at top speed?

[CogSim]

http://i.imgur.com/FVG3C69.jpg
Source: The Telegraph (http://www.telegraphindia.com/1140313/jsp/frontpage/story_18076946.jsp)

[Tfor2]

JMO, of course, but I think that high level politics is going on here. Civilian unrest meets DHS, whether of the USA, or China, or another sovereign state. Given the sophistication of modern military science, I think one or all know what happened, and where it is, and figure that high level security requirements take priority, and since they're all dead, they don't care. Let everybody run around like headless chickens, that's the price. JMO, as I said.

[Avionista]

If MH370 turned west from its last known position and, if it passed close to Pulau Perak as reported earlier by the Malaysian authorities, it would be on a track of 255 degrees (approx.). If it had enough fuel for 3000 nautical miles it could have come down about 200 miles south of the Seychelles.

A lot of "ifs", I know, but is this the scenario the Yanks are investigating?

[mabuhay_2000]

If, and it's a big IF, the US is onto something in the Indian Ocean, then a whole lot of questions suddenly pop up, don't they?

Like how come RR and Boeing apparently have no data supporting the theory?

Like why the heck they've wasted 5 days searching an area where they seem to think the aircraft didn't go down?

Like who is actually directing the SAR ops?

And many more...

[Sporky]

If it is found in the Indian Ocean, I along with quite a few others have stated that it might be there on this thread, obviously a hunch. Depressurisation would be the main candidate if it was found to be there I would have thought. The Malaysians might be in for an even rougher ride if MH370 flew straight back over their heads during the incident and rightly so.

[Fly26]

Thank you for the information, I was trying to figure out how accurate the search was, so in theory if it was there they would have come across it. If the decompression/hypoxia/reciprocal heading theory that many people suggest is anything to go by the MSAs around North Sumatra are high up to 13400, that terrain could hide an aircraft as well. It took a while to locate the sukhoi crash although weather did play a part hampering the search.

[OleOle]

The search area given by The Telegraph would make sense if it was established that the unidentified radar contact heading west was not picked up by Indian primary radar on the Andamans or Nicobars. The logical thing would be to comb that radar coverage gap in the middle with no primary radar coverage from either side.

If the "UFO" diverted to the SW (direction Diego Garcia) in that potential radar gap nobody would have noticed. Such a hypothetical diversion would bring into play the Pentagon. In Diego Garcia there must be some impressive surveillance equipment, AWACS and the like. Maybe something was picked up there ?

[mottie33]

I was about to ask the same thing.

Both Boeing and RR deny receiving any ACARS and either they are lying or telling the truth.
If they are telling the truth there is a third possibility: that ACARS was being sent but they didn't receive them.

Otherwise, why is this Destroyer being deployed at high speed to what should be the wrong position.

[grumpyoldgeek]

So what, if anything, do the US know that led them to redeploy the Kidd at top speed?

That one is easy. Either a US sub or a US sub killer picked up the ping.

[j.suarez]

To those who fly/work on 777s... How feasible is this?


1. Rapid decompression caused by exploding crew oxygen tank, or decompression aggravated by fault in cockpit oxygen tank/line;
2. Pilots don masks but there is no oxygen flowing and they aren't aware;
3. Pilots initiate descent and course reversal but mess up the interaction with the MCP and command FL295 instead of FL100 or similar;
4. Pilots become incapacitated within 30-60 seconds (time of useful consciousness as per source - http://www.casa.gov.au/wcmswr/_assets/main/fsa/2000/nov/20-23.pdf);
5. Incapacitated pilots inadvertently turn transponder to off or standby;
6. Pilots go unconscious as plane flies towards Andaman Islands/Bay of Bengal;
7. If spoilers had been deployed, A/T commands sufficient thrust to maintain (or attempt to maintain) MCP altitude and override effect of spoiler deployment;
8. Aircraft at near-max thrust runs out of fuel much more quickly than aircraft at cruise thrust, falls into the Bay of Bengal between Andamans and India/Sri Lanka.


What technical factors support or invalidate the above chain of events?


Thanks for all the input...

[mixduptransistor]

This is a big scoop for ABC news. Author is Martha Raddatz, absolutely impeccable sources and credentials, great, seasoned reporter.

What's becoming clear to me is that the U.S. (Pentagon and NTSB at very least) have better intel than the Malaysians, and, to protect the extent and sources of such data for reasons of national security and international relations, have had to find back-channel ways (the NTSB radar "advisors," NASA, etc) to leak the correct location of the aircraft to the Malaysians so as to seem to have them organically find it.

Unfortunately, with Vietnam etc. making good-faith efforts and taxing resources in a humanitarian gesture, the U.S. can't wait, sources are leaking to hurry this up. You can bet that was okayed at the highest levels and we have been talking to China.

My current theory is that the plane was hijacked but that the pilot flew it out into the ocean rather than to the specified destination.

This also helps explain why Douglas Feith, well-respected former NTSB investigator, was on air recently floating the turn-back/hijack scenario. At the time I thought he'd lost his bearings in all the media hype. Maybe more likely he had inside info.

Why would the US need to BS for a few days if they really knew where it was at? Does anyone really doubt the level of technology the US Government has available to them worldwide? Would it really be that damaging to the US intelligence community for them to say "we know where it's at, we'll tell you where, but we're not going to tell you how we know"?

Wait. Two questions.
First. Can you please provide a link for this information?

And second. Then why is the aircraft being searched on Indian Ocean? How can the ACARS datalink have stopped at the same time as the aircraft went off radar and the same aircraft have flown hundreds of miles West without transmitting any downlink?

Would someone please care to explain?

I don't have a link but I just heard audio on the top of the hour news break on NPR from the Malaysian government's press conference where they said they have spoken with Boeing and Rolls Royce and there was no data from the plane beyond when it dropped from radar.

[AA Milne]

If, and it's a big IF, the US is onto something in the Indian Ocean, then a whole lot of questions suddenly pop up, don't they?...

Yes and No.

The United States Navy has four Ohio class ballistic missile submarines on patrol at any given time, the United Kingdom has one Vanguard class ballistic missile submarine on patrol at any given time and France has one Le Triomphant class ballistic missile submarine on patrol at any given time, giving the US and its NATO allies potentially six submarines that could have detected wreckage.

Their patrols, routes etc are highly classified and none of the three nations would admit that one of their ballistic missile submarines was in the area, hence the way this might be being played out. There is even a possibility, especially in the case of the US, who are more likely to have one submarine in the area, they've sent one of their submarines to look in some deeper water, and they'll worry about explaining away any questions later.

[USAF1956]

They rarely are in that area and wouldn't be in an air defense role unless there were an active operation.

[bfd777]

New search area in Indian Ocean

It seems that the White House is better briefed than the Pentagon press office. Jay Carney, the White House spokesman, has just confirmed thata new search area*may be opened in the Indian Ocean, reports the Guardian’s Paul Lewis in Washington.“It is my understanding the one possible piece of information, or pieces of information, has led to the possibility that a new search area may be opened up over the Indian Ocean,” Carney said, without detailing the nature of the new information.He said discussions were ongoing with international partners to “deploy the appropriate assets” in any new search in the Indian Ocean. He added the new search would be based on “additional information” that was not yet “conclusive”.His comments appear to*confirm that earlier story*by ABC’s Martha Raddatz.

[the incivil beast]

I've always wondered how we get from 29.92 to a 1013.25 baseline myself.29.92 is inches of mercury, whereas 1013.25 is mbar (obsolete unit).

1 bar = pressure exerted by a force of 1 kilogram-force over a unit surface area of 1 square centimeter.

The official pressure unit is now the Pascal : 1 Newton over 1 square meter, hence 1 bar = 100 000 Pascal, 1mbar (millibar) = 100 Pascal aka 1 hPa (hectopascal)

[oriondt]

Missing Malaysia Airlines flight live: Satellites picked up 'electronic ping' from missing flight MH370 after it lost contact with ground control - Daily Record (http://www.dailyrecord.co.uk/news/uk-world-news/missing-malaysia-airlines-flight-live-3236617)

More details now on the 'electronic ping'.

A source close to the investigation said communications satellites picked up faint electronic pulses from Malaysian Airlines Flight 370 after it went missing on Saturday.

However, the signals gave no indication about where the stray jet was heading nor its technical condition.

The "pings" equated to an indication that the aircraft’s maintenance troubleshooting systems were ready to communicate with satellites if needed, but no links were opened because Malaysia Airlines and others had not subscribed to the full troubleshooting service, the source said.

[RatherBeFlying]

The US has some pretty impressive IR and visual surveillance satellites -- which may have picked up an airframe off route over the Indian Ocean along with several other airframes and surface craft on various civil and military missions.

[cynar]

In reply to mixeduptransistor ("Why would the US need to BS for a few days if they really knew where it was at? Does anyone really doubt the level of technology the US Government has available to them worldwide? Would it really be that damaging to the US intelligence community for them to say "we know where it's at, we'll tell you where, but we're not going to tell you how we know")

We didn't know instantly, obviously. Then, I'm sure, various agencies needed to both share intelligence and get a plan.

But if the Malaysians, in cooperation with neighboring countries, could find the plane, or be nudge-winked to the plane, that would yes be far preferable, for many geopolitical reasons.

And, in fact, that seems to be what's happening. In the NBC version, it is the *Malaysians* who have *asked the U.S.* to go a bit further west. And the U.S. "denies" we have specific intel. IMO exactly the reverse is true, and we are seeing a historical narrative being shaped.

U.S. Ship Moves to Strait of Malacca In Search of Missing Jet - NBC News (http://www.nbcnews.com/storyline/missing-jet/u-s-ship-moves-strait-malacca-search-missing-jet-n51931)

[TwoHeadedTroll]

A high calibre bullet fired into water gets about three feet. The idea that a 777 would have enough energy to get through 200 feet of water with enough energy to bury itself in the bottom seems surprising to me, especially as it is highly unlikely to be actually vertical at the moment of impact. Perhaps someone with a better understanding of fluid dynamics or, heaven forbid, some empirical data, could explain?

:bored:

[thcrozier]

Thank you, beast :) I've been scratching my head over that for forty years. Even spent a bit of time online trying to figure it out. Your explanation makes it clear.

[roving]

Having read the comments of the National Transportation Safety Board following its 'major investigation' into the loss of the Lear Jet in 1999, in which they opined that

"Investigations of other accidents in which flight crews attempted to diagnose a pressurization problem or initiate emergency pressurization instead of immediately donning oxygen masks following a cabin altitude alert have revealed that, even with a relatively gradual rate of depressurization, pilots have rapidly lost cognitive or motor abilities to effectively troubleshoot the problem or don their masks shortly thereafter. In this accident, the flight crew's failure to obtain supplemental oxygen in time to avoid incapacitation could be explained by a delay in donning oxygen masks of only a few seconds in the case of an explosive or rapid decompression or a slightly longer delay in the case of a gradual decompression. "

1999 South Dakota Learjet crash - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/1999_South_Dakota_Learjet_crash)

And the speculation here that the pilot's oxygen supply may have been compromised by airframe damage, am I to assume that there is no redundancy in the event that the primary oxygen supply is compromised?

[FMC]

I, as I'm sure many members on this forum have been totally astounded how a modern commercial airliner such as 777-2 could simply disappear without trace. We understand the limitations of radar coverage and that of SSR. Moreover the mystery of a final ACARS message at 1:07 and nothing from RR is worrying at best.

It is appreciated that all these systems fulfil separate and important functions pertaining to flight and health but there appears to be an apparent omission in terms of off radar tracking. It certainly appears that the 777 in question was certified for ETOPS 330 operation but that certification excluded the requirement for real time SATCOM tracking when out of radar coverage. (In reality such tracking would be continuous from TO to Land but legally required when out of radar coverage.

Such technology is readily available and deployed by law enforcement agency's and private firms. 3 separate SATCOM units fitted to the nose, mid-section and tail that feed continuous data on the A/C track, altitude, speed and fix in 30 second intervals. The SATCOM units retain battery backup so can transmit for up to 10 hours after power loss. In this situation even if the 777 had exploded in midair there would be likely data transmitted to alert SAR response.

The fact that this aircraft has been missing for nearly six days is an indictment and embarrassment to the regulations, manufacture, and the various agencies that control civil aviation. This is not dissimilar to the Titanic board of inquiry that focused on the actions of the crew rather than the fact that Titanic was certified to sail with only 50% lifeboat capacity. My point is how can you certify to 330 if you have no ability to find it in an emergency?

The cost to implement such tracking is too often traded off against the probability of such an incident. The hull loss in this case will prove to be insignificant against the civil actions . The wider issue is the perceive loss of confidence in the ETOPS system by pax who may vote with their feet on long oceanic routes such as ANZ1 NZAA - KLAX on 777-3ER where nearly the entire flight is out of coverage.

My point is that this incident has wide and powerful implications for the airline industry. NOTE: before you say it ( yes it also pertains to 4 holers)

[DaveReidUK]

Re Mode S:
It has a code you can enter for that flight, but also a code in the background unique to the airframe. It is - in computer terms - a MAC address and is used like that for data communications in the background.Yes, that's a pretty good analogy. The confusion in previous posts probably arises because "Aircraft ID" (ACID) is the term used in the ADS-B spec for the crew-configurable callsign/flight number, as distinct from the aircraft's hardwired 24-bit ICAO address.

Does the 777 let the pilots change the tail number as well as the flight ID?The tail number isn't transmitted via the transponder, except in cases where it's being used as the callsign for the flight. It can, of course, be ascertained from the 24-bit address, so it's not really necessary.

[ChicoG]

Why would the US need to BS for a few days if they really knew where it was at?

Perhaps they want to get to it first? To make sure that the cause of the crash is properly established?

Remember MS990.

[xcitation]

If, and it's a big IF, the US is onto something in the Indian Ocean, then a whole lot of questions suddenly pop up, don't they?

Like how come RR and Boeing apparently have no data supporting the theory?

Like why the heck they've wasted 5 days searching an area where they seem to think the aircraft didn't go down?

Like who is actually directing the SAR ops?

And many more...

When a radio transmission is attempted but fails because of no hand shake response from the ground station, it will retry at a set interval. If the a/c is out of range from ground receiver then other sensitive (surveillance) radio equipment might passively detect these pings without responding. The signal can then be decoded given the appropriate signals analysis equipment.

Think of your cell phone. When out of range it sends a ping periodically seeking a handshake back from the tower. A radio receiver can detect that ping passively without any response and the receiver could even decode it if they have the right equipment. This is one explanation of how the signal was detected yet not relayed to RR or Boeing. To clarify the ping is only a short high power signal giving some very basic ID and ready to send data. It is not the full data transmission. If you have more than one receiver it is possible to triangulate the transmit location.

This technology in WW2 gave British fighter command an early warning of the German bombers coming over for raids. Needless to say signals analysis has come a long way since then.

[brika]

Despite MAS and Boeing/RR saying no data was transmitted after 1:07 am, the US are proceeding to search the Indian Ocean:

Communications satellites picked up faint electronic pulses from Malaysia Airlines flight 370 after it went missing on Saturday, but the signals gave no indication about where the stray jet was heading nor its technical condition, a source close to the investigation said early today.

The "pings" equated to an indication that the aircraft's maintenance troubleshooting systems were ready to communicate with satellites if needed, but no links were opened because Malaysia Airlines and others had not subscribed to the full troubleshooting service, the source said.

Two sources familiar with the investigation into the disappearance of the jet five days ago also confirmed that manufacturers Boeing and Rolls-Royce did not receive any maintenance data from the jet after the point at which its pilots last made contact.

Only one engine maintenance update was received during the normal phase of flight, they said, speaking on condition on anonymity.

Boeing and Rolls-Royce declined comment. - Reuters, March 14, 2014.

In a statement released today, the US Navy announced that from March 15, a P-8A Poseidon will be commissioned to the Strait of Malacca to aid in search efforts.

MARCH 13, 2014 - themalaysianinsider.com

[er340790]

One way or another this loss (and it is one) is going to trigger a MASSIVE insurance pay-out. There must be hordes of very nervous insurance underwriters and reinsurers currently scouring the small-print of the MAS policies.

Have there been any estimates as yet on the 'hull-loss' of a 2002 777-200ER?

It will also be interesting to see how the personal life-assurance 'relativities' for those pax from China and other ASEAN nations stack-up compared to those from other / developed nations.

Even the most conservative figures must already run into many hundreds of millions of $s. Factor in any possible negligence and the sky's the limit (excuse the pun). That is before S&R / recovery operations are factored in.

Did any 'final' figures ever get published for AF447?

[V-Jet]

There are multiple O2 bottles aside from the a/c built in supply.

None will work if you dont know you are incapacitated.

The question I still have is how long does it take to 'wake up' once the aircraft is below about 15,000'? I would have have thought that unless it was descending very fast there would be time to regain consciousness prior to impact.

Anyone know?

[quentinc]

Like how come RR and Boeing apparently have no data supporting the theory?

Maybe they didn't.... but perhaps those able to monitor at a lower level... could see something: MISSING MH370: Satellites picked up "pings" from Malaysia jet, source says - Latest - New Straits Times (http://www.nst.com.my/latest/font-color-red-missing-mh370-font-satellites-picked-up-pings-from-malaysia-jet-source-says-1.511912)

What is not said in the article is at what times/for how long these pings occurred... and if it was possible to work out the location of where the signal was....

[mixture]

The fact that this aircraft has been missing for nearly six days is an indictment and embarrassment to the regulations, manufacture, and the various agencies that control civil aviation. This is not dissimilar to the Titanic board of inquiry that focused on the actions of the crew rather than the fact that Titanic was certified to sail with only 50% lifeboat capacity. My point is how can you certify to 330 if you have no ability to find it in an emergency?


All well and good to bang your fists on the table and shout and scream, but allow me to remind you of one thing.

First flight of the 777 was (according to Wikipedia) June 12th 1994.

That means design, development etc. would have been occurring in the 5-10 years prior to 1994.

The world of technology was a vastly different place then.

Retrofiting onto an old design is probably a right pain from both a manufacturing and regulatory point of view.

That is probably why it is the way it is, and why, going forward we'll probably see developments. But the developments will be as result of technology making it easier / cheaper to do stuff than it was in 1994 ... rather than as a specific consequence of this incident.

What I am surprised at though, is given satellites and other secret squirrel monitoring systems out there, that the aircraft has not been located by the intelligence community by now..... (although I guess the conspiracy theorists might suggest they've been gagged by the big cheeses in the name of "national secewwity"!).

[LASJayhawk]

The ICAO code translates to the aircrafts registration number. It is part of the squitter message and is sent out about once a second if the transponder is on even if the transponder is not being interrogated by a ground station or a TCAS box.

[OldDutchGuy]

A high calibre bullet fired into water gets about three feet. The idea that a 777 would have enough energy to get through 200 feet of water with enough energy to bury itself in the bottom seems surprising to me, especially as it is highly unlikely to be actually vertical at the moment of impact. Perhaps someone with a better understanding of fluid dynamics or, heaven forbid, some empirical data, could explain?

The aircraft is not a solid object; it is a skeleton structure. Water, when impacted at speed, has the effective resistance of concrete. Water is an incompressible fluid; it has no "give." The aircraft will NOT penetrate through the water surface; instead, the skeleton will collapse and disintegrate (the point loads on the skeleton members are way above the points of deformation and failure). To understand this, look at photos of the re-assembled TWA 800 in that hangar on Long Island. Thousands of pieces.

You end up with a large debris field. The denser items will sink; structures where the density of the whole is less than water (which is conveniently calibrated as 1.00) will float. You might be surprised at how much of the aircraft components are less dense than water: all the plastics, the seats, carpeting, various thermoformed panels, clothing, most luggage, the fuel, and so forth. Even sections with aluminum may float if less dense items remain attached, or air becomes trapped in a pocket section. Also, invariably a large number of the bodies will be floating. In both TWA 800 and Iran Air shoot-down in the Persian Gulf by the USS Vincennes, large numbers of bodies floated and were recovered.

The suggestion is made that fishermen would not recognize aircraft parts as being from an aircraft. Perhaps. Yet, fishermen are not going to misunderstand that bodies floating about are from anything other than some disaster. That, at least, would be reported. It is because of these two aspects - large debris field and over 100 bodies, perhaps 200 floating bodies - that it is implausible to me that this aircraft, after six days of searching by over 100 units in calm seas, went down where the search is going on. And if the A/C did not go down on the water, then my conclusion is that it continued North on its flight path and crashed on land. And if on land, then assuredly not in a populated area; the further conclusion is that it bored a hole in the jungle, at a 70-degree (inverted?) angle, making a 30-ft diameter bore hole, and you don't find it. Gone.

Unless, it really did make that 90-degree turn to the West, and kept on flying, and .....

[olasek]

The world of technology was a vastly different place then.
If this was a 787 that disappeared I doubt it would be any easier to find it.

[Elephant and Castle]

how can you certify to 330 if you have no ability to find it in an emergency?

Because ETOPS 330 refers to the aircraft redundancy and resilience to cope with a significant failure and continue for fly for up to 330 minutes and land at a suitable airfield. It does not refer to your ability to find it.

[Old Boeing Driver]

One of the million or so scenarios that have been offered is that there was an explosive decompression, which involved the elctronics bay and crew O2 area beneath the cabin floor and just aft of the cockpit.

Whatever happened rendered the radios and transponder, as well as the crew O2 inop. Apparently it did not affect the A/P.

The crew had a enough useful consciousness to get a bit of a descent and a return heading set, possibly to an FMS waypoint before passing out.

The plane descended to the preset altitude and went west.

[FMC]

Elephant & Castle yes I know but a glaring omission in the certification. Clearly this aircraft was just out of coverage and no one has a clue after six days so time to change the certification as one can only imagine the SAR ability if this was 240 or 330 minutes over the pacific?

[brika]

It would probably be the first time that NASA's technology would be tested in Aircrash investigations:

"Activities under way include mining data archives of satellite data acquired earlier and using space-based assets, such as the Earth-Observing-1(EO-1) satellite and the ISERV camera on the International Space Station, to acquire new images of possible crash sites," NASA spokesman Allard Beutel told Space.com.

March 13, 2014 10:42 AM - ibtimes.co.uk

[averow]

Rest assured that American (and presumably Chinese and Russian) intelligence
assets have capabilities far in advance of what they are wiling to publicly advertise.

In the mid 1990s I was involved with a lengthy SAR effort with ground searchers
And Civil Air Patrol assets. We were running up quite a fuel tab with the CAP when it was discretely suggested by the Air Force liaison that we go to such and
Such a position, hundreds of miles away from the last known position and nowhere near what we had brainstormed as a possibility. The airplane and crew were found by us immediately albeit with no chance that the people on board had survived the crash. No information was ever given to us as to how they had ascertained this particular location.

I suspect that something similar is going on with the USN assets steaming to the
scene now.

[ZeBedie]

I tried to make the point that, in the past, it was common practice to select STBY on the transponder before selecting a new code, but my post disappeared into the ether!

So what if, TOC, one pilot goes back for a comfort break (likely time for it), explosive decompression, remaining pilot, stunned by events, starts a descending turn, put transponder to STBY, selects 7700 and then goes hypoxic, having failed to make donning the mask his first action?

[413X3]

Lost in Saigon has been a never ending stream of misinformation and lies. Can someone tell his mom he should stop pretending to be a pilot online?

[JayFor]

Please correct me if I'm wrong, but I can't find the exact quotes buried several days ago in the thread.

But haven't all of the statements from Malaysia denying ACARS messages been very cautiously worded, and stopped short of complete denials that there was any signal received by ANYONE, ANYWHERE?

The first statement, from several days ago, if I recall correctly, seemed to be "the last message MAS rec'd was at 1:07" and then the next sentence was worded a bit differently--"no distress signals were sent."

The wording the other day was that the US claims were "inaccurate," and that Boeing, RR and MAS did not receive any ACARS messages -- but that does not exclude the possibility that someone else DID receive this (or something).

And I thought Boeing and RR themselves did not directly comment.

I've just thought that these "denials" have stopped short of complete denials, and indeed, have been awkwardly worded in so doing.

[areobat]

What is the maximum recording time for the FDR and/or CVR on a 777? It occurred to me that if MH370 indeed flew on for several more hours after the incident (whatever it was) that the relevant portion of the data stream may have been over written by the later stages of the flight so we may never know precisely what transpired.

[Nik4Me]

The fact of transponder being off - it bothers me - such a simple thing,

-result of the unknown systems failure-all out?
-off accidentally by a disabled(smoke or O2 loss), stumbling, crew without ill intent?
-ill intent? What is the significance of transponder being off, if that is the case?
- coincidental malfunction like on AI127 at the time when a major event leading to the plane loss was occurring or just about to occur?

What do the 777-200 pilots think is most probable- how soon would you know that the transponder malfunctions, what are the remedial steps?

Apologies to mods, but it is not just about speculations- the transponder was off, it is the first known fact and undisputed fact

[GarageYears]

@ areobat

I believe the CVR recording duration before over-write is 120 mins. The FDR is 25 hours AFAIK.

[auv-ee]

OleOle,
I understand the "satelite ping" thing as the iridium/inmarsat equipment of MH370 logging in to the iridum/inmarsat network. So it seems the backlogs of the network have been evaluated. I don't know how precise the position of the iridium/inmarsat transceiver can be infered from those logs.I have no idea what satellite assets are used for the aircraft maintenance comms: Iridium, Inmarsat or something else. However, if Iridium is involved, then the satellites locate the terminal (modem) to within about 10km E-W and 1km N-S. The asymmetry has to do with orbits or antenna patterns or something. Iridium was once able to tell us to about this accuracy where to find one of our assets, and, sure enough, it was within or near to those parameters.

[Southernboy]

Forgive me if someone's already covered this, my search revealed nothing.

The FAA have issued an airworthiness directive for 777s regarding fatigue cracks around the SATCOM atenna adaptor which could lead to "rapid decompression and loss of structural integrity"

Effective April 2014

[brika]

The Decompression theory appears to have a lot of support in this discussion:

Last night it emerged that the US aviation watchdog warned airlines six months ago of a problem with cracks in Boeing 777s that could lead to a mid-air break up and a catastrophic drop in cabin pressure.

The Federal Aviation Administration issued an alert in September last year giving airlines until April 9 to detect and correct cracking in the fuselage skin on Boeing 777s.

The FAA warned that failure to do so would leave the aircraft vulnerable to ‘a rapid decompression and loss of structural integrity’.

The organisation issued a final directive just two days before the Malaysia Airlines plane took off and said one airline had found a 16-in crack in the fuselage skin of a 14-year-old plane.

However, Boeing said that the FAA alert did not apply to the missing jet because it did not have the same antenna as the rest of the Boeing 777s.

And Malaysian Airlines insisted that the missing Boeing was airworthy before taking off, but declined to reveal whether it had been inspected for a known potential problem with the fuselage.

During a sudden drop in cabin pressure, the crew and passengers can become unconscious, leaving nobody in control of the aircraft.

mirror.co.uk - Mar 13, 2014 00:13

Perhaps 777 pilots can shed some light about how true this is.

The question is, if this is true, then, at around TOC is this the prime time for this disaster to happen?

[CogSim]

Because ETOPS 330 refers to the aircraft redundancy and resilience to cope with a significant failure and continue for fly for up to 330 minutes and land at a suitable airfield. It does not refer to your ability to find it.

In other words, you can shut down one engine and extend the range by upto 330 minutes?

[EcamSurprise]

put the transponder to standby, select 7700

My points on this statement:

1) My understanding is that this isn't required on the 777 (albeit maybe something from the past).

2) If I was in an emergency situation, my first action would not be to set the transponder. Aviate, Navigate & Communicate and all that good stuff. I would be on 02 and getting the aircraft going down. If I am by myself in the cockpit, then the 'flow' of bits like belts, pax 02, transposer and coms would be secondary to getting the aircraft established in a descent or under control.

3) Isn't the purpose of going to SBY to avoid accidentally setting one of the 'major' squawks. I.E 7700, 7500 or 7600.
If I was in an emergency situation, and I wanted to set 7700 anyway, why would I care about going to SBY first?

This just seems like an explanation which conveniently fits a scenario, but just doesn't come across as realistic.

IF all sorts is hitting the fan, to the extent that I FORGET to put my 02 Mask on as my very first action, then it is probably because I am attempting to control the the aircraft NOT faffing around with setting a squawk.

Lastly, with emergency descent perhaps being the exception, does everyone always set 7700 before talking to ATC? I'd find it more instinctive to be getting out some form of Mayday rather than playing with a squawk as my primary action or at the very least doing it at the same time. Even if it were a "Mayday Mayday Mayday, XXXX, Emergency Descent / Fire / Etc, STANDBY."

Just my thoughts.
I just don't buy it that someone would be playing with a transponder BEFORE descending the aircraft (if needed) as seen by the fact no change of course / altitude was detected and BEFORE going on 02. These are professional crews and I'd suggest 02 is a instinctive action.

[snakepit]

Well, if we do find this aircraft in the Indian ocean, that really only leaves one of two most likely scenarios:

1. Hi-jack

2. Foul play amongst one of the crew members. All it would take would be one crew member goes to the bathroom and the guy on the flight deck locks him out.

Hypoxia is still a possibility, but less so than 1 and 2 above. One needs a really big hole to get a decompression, and that would have been followed by a rapid descent, which didn't happen here. And we know the pressurization was functioning correctly since they cruised for awhile, so you can reasonably rule out a improperly set pressurization control


Mmm not true at all. One only needs a hole bigger than the outflow valves diameter and they are not usually that big. The alternative would be loss of pressurisation due to loss of incoming air from the ac packs 1&2 (can any 777 drivers confirm if they fail closed with power loss?) which could have conceivably happened when/if everything else failed rendering comms and txponder in-op.

[wiggy]

Whatever happened rendered the radios and transponder, as well as the crew O2 inop. Apparently it did not affect the A/P.


" Apparently it did not affect the A/P."

and there to my mind is the problem with the theory of the crew O2 bottle exploding and causing the accident - you've got to come up with a way of explaining how a fire/explosion can disable significant comms components in the MEC but seemingly leave the A/P and all it's associated systems intact enough to "fly" the aircraft, according to some theories for several hours. Credible? One for our engineering colleagues to answer I think.

And while I'm at it if anyone has to be informed yet again that on the 777 you do not turn the transponder to standby to change the code, you just punch in the code.....and touching the transponder at all, even a teeny bit, is not part of the Boeing Rapid Descent procedure I'll..........cry:{

[dmba]

Boeing says Malaysia jet not subject to FAA inspection order | Reuters (http://www.reuters.com/article/2014/03/12/us-malaysia-airplane-faa-idUSBREA2B1YN20140312)

"Boeing said it worked closely with the FAA to monitor the fleet for potential safety issues and take appropriate actions. But it said the 777-200ER Malaysia Airlines aircraft did not have that antenna installed and was not subject to the FAA order.

An FAA spokesman on Wednesday also cautioned against linking the directive, one of hundreds issued annually by the agency, to the disappearance of Malaysia Airlines flight MH370."

[Ian W]

I, as I'm sure many members on this forum have been totally astounded how a modern commercial airliner such as 777-2 could simply disappear without trace. We understand the limitations of radar coverage and that of SSR. Moreover the mystery of a final ACARS message at 1:07 and nothing from RR is worrying at best.

It is appreciated that all these systems fulfil separate and important functions pertaining to flight and health but there appears to be an apparent omission in terms of off radar tracking. It certainly appears that the 777 in question was certified for ETOPS 330 operation but that certification excluded the requirement for real time SATCOM tracking when out of radar coverage. (In reality such tracking would be continuous from TO to Land but legally required when out of radar coverage.

Such technology is readily available and deployed by law enforcement agency's and private firms. 3 separate SATCOM units fitted to the nose, mid-section and tail that feed continuous data on the A/C track, altitude, speed and fix in 30 second intervals. The SATCOM units retain battery backup so can transmit for up to 10 hours after power loss. In this situation even if the 777 had exploded in midair there would be likely data transmitted to alert SAR response.

The fact that this aircraft has been missing for nearly six days is an indictment and embarrassment to the regulations, manufacture, and the various agencies that control civil aviation. This is not dissimilar to the Titanic board of inquiry that focused on the actions of the crew rather than the fact that Titanic was certified to sail with only 50% lifeboat capacity. My point is how can you certify to 330 if you have no ability to find it in an emergency?

The cost to implement such tracking is too often traded off against the probability of such an incident. The hull loss in this case will prove to be insignificant against the civil actions . The wider issue is the perceive loss of confidence in the ETOPS system by pax who may vote with their feet on long oceanic routes such as ANZ1 NZAA - KLAX on 777-3ER where nearly the entire flight is out of coverage.

My point is that this incident has wide and powerful implications for the airline industry. NOTE: before you say it ( yes it also pertains to 4 holers)


I fully agree with your points. The cost these days of a simple SATCOM device to ping its GPS position is peanuts even including the cost of certification (some are probably already certified).

Considering the astronomical cost of the current rescue that will almost certainly be borne by the insurance underwriters, it is not unlikely that insurers may withdraw insurance from any aircraft flying out of LOS of land unless it has some kind of standalone self-powered tamper proof SATCOM tracking. It doesn't matter what the beancounters in the airlines say, if their insurers will not cover them unless they are equipped; they will be equipped.

[tdracer]

Like how come RR and Boeing apparently have no data supporting the theory?

I wouldn't read too much into the lack of response from Boeing or RR. During an accident investigation, the manufactures are effectively under a gag order. All official communications are to come from the investigating agency.
While I've never known an investigating agency to blatantly lie, I have stewed quietly a few times when they couldn't be bothered to officially dismiss speculation or theories that we'd already disproved. All that being said, I think the idea that a US intelligence agency has access to some data that no one else does is plausible, perhaps even likely.

BTW, most modern FDR are capable of recording the max capable flight length, so there is little risk of the relevant data being overwritten unless the plane landed somewhere, refueled, and took off again (at this point I'm not sure I'd rule out much of anything).
The voice recorder is a different story though.

[LASJayhawk]

A/P FCS can get power from any buss like the pilots windshield heat.

Lot of other wis bang stuff gets load shed if major busses go off line.

But one does wonder if it was jacked, if they though the plane was fully fueled and would have more range than it did.

[albatross]

Someone asked a question about ETOPS.
Here is a short Boeing Video explaining it on the 777

New ETOPS rule extends 777's performance - YouTube (http://youtu.be/W_azlwNlTgI)

Just FYI ETOPS planning takes into account both failure of an engine and / or decompression along with other criteria such as loss of electrical power.

[Old Boeing Driver]

I agree with your comments about the transponder. Not sure a radar sweeps are fast enough to catch code changes anyway.

I'm not familiar where all the components are located in that electronics bay either.

There is always the possibility that the transponder just happened to fail...I know not probable.

[hamster3null]

I am wondering:
-how many unidentified plots on a radar were seen at the time MH370 went missing. Not much I guess.
-how much effort does it take to analyze the recording to learn alt, speed, heading of the plot
-how much other radars other than the Malaysia military could have picked up this plot on radar? Phuket?

so why does it take so much time to either confirm or rule out this unidentified plot was MH370?

The "unidentified target" was tracked by the radar at RMAF Butterworth. It crossed Malay Peninsula over Thai territory, well north of the border.

MH370 went silent roughly 215 NM from Butterworth. If it turned towards Phuket, its route would have passed over the middle of Gulf of Thailand, likely never getting closer than 150 NM to the radar. If whoever was piloting it knew about the military installation, they could have stayed at 200 NM all the way. It would stay at the edge of radar range and they'd only have an intermittent track that did not extend far enough back to connect to last known position of MH370.

As far as I can tell, Thailand does not have any active air force bases on the peninsula. At best the "target" could have been tracked by a couple of civilian ATCs there. Neither does Vietnam have any bases close enough to catch the moment MH370 turned off course.

[Chronus]

The aircraft has now been missing for six days. Assuming a mid air break up or break up on impact with water, there must have been some floating debris. It would be reasonable to expect that had this ocurred over the Malacca Narrows, bye now some floatsam would have reached the shores of these straights.
On the basis of a 5kt surface current, the floating debris would have travelled 720nm. It would be reasonable to expect that the SAR
co-ordination team would have taken this into consideration and concentrate their efforts taking into account the direction of surface water movements. However even if the point of break up is currently based on best guess, it is only a matter of time before some debris is washed up on someone`s shores. It is then that the real hard work of finding the location of the main wreckage will commence.

[ildarin]

First item in your immediate action checklist is put your oxygen mask on when there's an excessive cabin altitude warning.

Didn't work so well for Helios 522...

[glendalegoon]

the helios crew did not recognize the BLARING HORN as cabin altitude warning, they thought it was the landing gear horn. same sound, different interval.

so they didn't put them on.

[hamster3null]

Assuming that explosive decompression renders the heating system ineffective resulting in a cabin temperature of -20C, the crew and passengers will freeze to death in a few minutes. NIH lists survival time as 8.5 minutes at -20C.

I think you badly misread your source. 8.5 _minutes_ survival time does not even pass the smell test. At -20C in room-temperature clothing and without complicating factors (e.g. wind chill or rain), survival time is going to be on the order of 12 hours.

However, if you combine -20C temperature with hypoxia, things are going to turn badly much faster.

[WillowRun 6-3]

Correction: Satellite, Not Engine, Data Drove Investigators’ Suspicions on Malaysia Jet Flying Time
U.S. investigators suspect that Malaysia Airlines Flight 370 stayed in the air for up to four hours past the time it reached its last confirmed location, according to two people familiar with the details, raising the possibility that the plane could have flown on for hundreds of additional miles under conditions that remain murky.

The investigators believe the plane flew for a total of up to five hours, according to these people, based on analysis of signals sent by the Boeing 777's satellite-communication link designed to automatically transmit the status of some onboard systems to the ground.

Corrections & Amplifications: An earlier version of this article incorrectly said investigators based their suspicions on signals from monitoring systems embedded in the plane’s Rolls-Royce PLC engines and described that process.

[OPENDOOR]

the helios crew did not recognize the BLARING HORN as cabin altitude warning, they thought it was the landing gear horn. same sound, different interval.

They also ignored an engineers question;

"Can you confirm that the pressurization panel is set to AUTO?":ugh:

[SaturnV]

PPRuNe gets a favorable review in the NY Times.

http://www.nytimes.com/2014/03/13/world/asia/online-and-onscreen-disappeared-malaysian-flight-draws-intense-speculation.html?action=click&contentCollection=Asia%20Pacific&region=Footer&module=MoreInSection&pgtype=article
________________________

The Wall Street Journal reporter who still stands by the core of his story, is one of the top, if not the top, aviation reporter at the Journal. Martha Raddatz, the defense reporter at ABC News, is very well connected with national security sources. IMO, the U.S. government is selectively leaking information.

Based on the Wall St. Journal reporter's accounts, the pinging lasted for four hours, at 30 minute intervals. So there was power and a functioning communication link during that interval. Depending on whether the U.S. can triangulate the location of each ping, that would give an approximate a location at the time of the last ping. That leaves up to a 30 minute flying distance from the point of the last ping.

According to the Journal reporter's radio interview, he mentioned several times that U.S. officials haven't ruled out the plane landing, or crash-landing on land.

[shawk]

I think you badly misread your source. 8.5 _minutes_ survival time does not even pass the smell test. At -20C in room-temperature clothing and without complicating factors (e.g. wind chill or rain), survival time is going to be on the order of 12 hours.

However, if you combine -20C temperature with hypoxia, things are going to turn badly much faster.

Yes, misread M for H in the abstract. The NIH number is 8.6 hours at -20C with two layers of loose clothing. Recovery time after several hours of -20C is fairly lengthly.

[VFR Only Please]

It would be reasonable to expect that (the crash) ocurred over the Malacca Narrows.

Really? Shouldn't that be the Gulf of Thailand, a much bigger body of water?

[CommanderCYYZ]

This is what Reuters had to say about the techies. Not sure that anyone said anything specific about the technology they were working on.

Loss of employees on Malaysia flight a blow, U.S. chipmaker says | Reuters (http://www.reuters.com/article/2014/03/09/us-malaysia-airlines-freescale-idUSBREA280T020140309)

[hamster3null]

Correction: Satellite, Not Engine, Data Drove Investigators’ Suspicions on Malaysia Jet Flying Time
U.S. investigators suspect that Malaysia Airlines Flight 370 stayed in the air for up to four hours past the time it reached its last confirmed location, according to two people familiar with the details, raising the possibility that the plane could have flown on for hundreds of additional miles under conditions that remain murky.

The investigators believe the plane flew for a total of up to five hours, according to these people, based on analysis of signals sent by the Boeing 777's satellite-communication link designed to automatically transmit the status of some onboard systems to the ground.

Corrections & Amplifications: An earlier version of this article incorrectly said investigators based their suspicions on signals from monitoring systems embedded in the plane’s Rolls-Royce PLC engines and described that process.

What's "Boeing 777's satellite-communication link designed to automatically transmit the status of some onboard systems to the ground"? Do they mean SATCOM? So, MH370 did have SATCOM hardware?

Also of interest:

"Throughout the roughly four hours after the jet dropped from civilian radar screens, these people said, the link operated in a kind of standby mode and sought to establish contact with a satellite or satellites. These transmissions did not include data, they said, but the periodic contacts indicate to investigators that the plane was still intact and believed to be flying."

[hamster3null]

Yes, misread M for H in the abstract. The NIH number is 8.6 hours at -20C with two layers of loose clothing. Recovery time after several hours of -20C is fairly lengthly.

Just to nitpick, that's for -30C.

[ZAZ]

Boeing did state that an airworthiness directive about possible fuselage cracks issued by US authorities in November regarding 777s, which had been linked in some theories to flight MH370, did not apply as the missing plane did not have the specific antenna installed.


However, the Malaysian authorities said reports that more data had been transmitted automatically by the plane after it went missing were inaccurate, adding that the final information received from its engines indicated everything was operating normally.
A report in the Wall Street Journal had claimed that US investigators believed the plane had flown for five hours (http://online.wsj.com/news/articles/SB10001424052702304914904579434653903086282), based on data allegedly transmitted to Rolls-Royce, the British engine manufacturers.
But Malaysia (http://www.theguardian.com/world/malaysia) Airlines chief executive, Ahmad Jauhari Yahyain, told reporters: "We have contacted both the possible sources of data – Rolls-Royce and Boeing – and both have said they did not receive data beyond 1.07am. The last transmission at 1.07am stated that everything was operating normally."
A Reuters report said sources close to the investigation claimed communications satellites picked up faint electronic pulses from the plane after it went missing, but the signals gave no indication where the jet was heading nor its technical condition. They said one engine maintenance update was received during the flight.
Neither Boeing nor Rolls-Royce would comment, citing international conventions on air accident investigations.

[Ian W]

There are multiple O2 bottles aside from the a/c built in supply.

None will work if you dont know you are incapacitated.

The question I still have is how long does it take to 'wake up' once the aircraft is below about 15,000'? I would have have thought that unless it was descending very fast there would be time to regain consciousness prior to impact.

Anyone know?

I can only quote from subjective experience way back when we were put in small groups into 'the chamber' to experience and watch each other get hypoxic. The chamber was 'climbed' to (I think) about 30,000ft equivalent.

We were given a simple maths test to work out - write down 500 now start subtracting 17 - then one in each pair had their oxygen switched off.

I became woozy and not with it relatively rapidly say 45 seconds or less but subjectively within 20 - 30 seconds was back up to speed when given 100% oxygen. My 'partner' seemed to be totally unaffected when his supply was shut off neatly writing sum after sum.... it was only when we looked after about 45 seconds we noted that although the writing was neat it was gibberish... he also recovered quite rapidly 20 - 30 seconds or so.

So what we learned was onset can be fast and obvious - or fast and not obvious, imagine the FO happily punching nonsense into the FMC. Recovery - on 100% oxygen was rapid. However, we had not spent a long time at height and were young and relatively fit. I expect as with all things biological YMMV.

[jehrler]

It could be, it seems to me, that the WSJ reporter still does not have it right.

As noted above and before, it seems that this T7 did not have SATCOM so how could it be transmitting pings to satellites?

What if what was actually pinging was the ACARS/RR monitoring radios but these transmissions were picked up by NSA satellites?

That seems more likely and could explain the confusion of the reporter and his source(s).

[captplaystation]

I am neither familiar to a great extent with the FBW architecture of the Bus , nor the 777. However, from what I understand it operates ( without Autopilot engaged ) in a form vaguely similar to CWS on my "steam driven" 737, I.E. the aircraft will more or less maintain the same angle of pitch/bank, and within certain limits , return to same if disturbed.

This being the case, given that they had already attained cruise altitude, unless whatever catastrophe that occurred interrupted electrical power such that power to the FBW was disabled, any discussion involving the autopilot is without value, as the aircraft would have continued in controlled flight anyhow until fuel exhaustion.


As a footnote, I think more is known than is being released (particularly radar data) & find it difficult to believe that Satellite data etc would not be available.

Having said that, it took from 5 days to 2 years between finding surface wreckage & anything useful in the Air France accident, so don't hold your breath.

[Chronus]

Please read it again, you will note that it says it would be reasonable.. had it ocurred ... it is a proposition that had it, then given this narrow channel of water it would be reasonable to expect that there would be some flotsam. So as no flotsam why are they still busy dreging this narrow water way.

[Johnny Albert]

Dear pro pilots and engineers,
This thread has over 4 million views... safe to say it's gone viral amongst non-professionals, regular folks just listening in on a fascination conversation.
So, first, thanks.

I realized I was missing half the conversation, not knowing what the many abbreviations and acronyms that are commonly referred to in these posts (SAR, NIH, PAX, UTC, ACARS etc.) So I thought I would provide a link to a wiki page which could help us amateurs follow along and possibly prevent us from asking dumb questions.

List of aviation abbreviations - Wikipedia (http://en.wikipedia.org/wiki/List_of_aviation,_aerospace_and_aeronautical_abbreviations)

Again, many thanks.

[VinRouge]

Interesting thing with hypoxia, and in pass this on to all who haven't done a chamber run, YOU FEEL MUCH WORSE POST HYPOXIC WHEN YOU GO BACK ON OXYGEN!

Effectively, your blood flushes the crud that has built up, meaning you get this god awful head rush, dizziness and nausea. Have done the training fairly recently experiencing rapid onset (easy to diagnose) and slow onset (difficult, even when my blood oxygen level dipped below 60%, and I was expecting it). The hazard is people have been known to rip off the mask trying to get rid of the sensation.

By far the worst most dangerous hypoxia was the slow onset, which is very subtle and why good CRM is essential.

Problem is, at 02:00, many of the signs and symptoms are very similar to heavy tiredness, meaning they can be missed.

With the advent of hypoxia simulators as opposed to old school chamber runs, there is NO REASON why airline pilots should not have to undergo this training on a 5 yearly basis, similar to the military requirement.

Did the jet have any form of sat based data comms, ie in flight entertainment or passenger telephone?

[FIRESYSOK]

I'd suspect, perhaps incorrectly, that a 777-200ER with an airline like MAS would more than likely be kitted with SATCOM.

Just because the airframe in question did not have a particular SATCOM antenna subject to an AD does not mean it didn't have one period.

I would also think the comm system would have to be "logged on" to ensure it was operational on demand.

How would an international airline maintain 'operational control' without SATCOM? VHF/HF voice-data only? Unlikely.

[awblain]

A successful ditching, with no distress beacons, on a moonless night? In an aircraft not able to continue on its way or head for an airfield?

Doesn't sound very likely.

While you'd want to aviate first, if you were going into the sea, having a word with someone might help, at least to let them know what time you were going into the sea, so they could use a piece of string and a ruler to come and find the debris afterwards.

[Chronus]

Rather than why the aircraft went down, I believe the real interest at present must be WHERE IS IT.

Given the total futility demonstrated by electronic means to locate any wreckage, it must follow that the search methods will have to be based on the hydrodynamics of the Andeman Sea and the Malacca Straight.

Those interested in the subject may refer to the American Journal of Environmental Science, 2012,8 (5), 479-488, General Circulation in the Malacca Straight and the Andaman Sea.

Here is a link to it.

https://www.google.co.uk/url?q=http://thescipub.com/pdf/10.3844/ajessp.2012.479.488&sa=U&ei=WQ8iU8_SM8mqhAemkIDYBQ&ved=0CCQQFjAB&usg=AFQjCNG246IxVHjWkdHjW1Bsn20njh-ifA

[wiggy]

capn p

I.E. the aircraft will more or less maintain the same angle of pitch/bank, and within certain limits , return to same if disturbed.

As an end user I reckon the T7 handles much the same as most other "normal" non FBW aircraft I've ever flown but with the addition of one or two knobs and whistles (like pitch/power couple taken out). If the aircraft is trimmed properly for the IAS at an attitude then disturbed from that datum attitude it'll eventually return to that datum (blimey, memories of CFS S&L 2) just like a Cessna or a JP - it doesn't do anything magic like pop straight back to the datum attitude if the stick is released with the aircraft close to datum ( if that's what CWS does?) - Interesting point and I guess we need someone with both 737 and 777 time to referee.

[GarageYears]

I believe that this particular T7 DID HAVE Satcom, just not the Satcom antenna per the recent Boeing AD. Not the same thing at all.

[cockpitvisit]

If you were seeking asylum, why would you use a stolen passport?

Because the airline will not let you onboard without a visa otherwise.

[Bill Macgillivray]

I am reluctant to post on this topic (being very old and retired!) but I have a reasonable amount of flying experience (civil & military) and have flown in that part of the world. My knowledge of the 777 is nil but I have a reasonable idea of what is available on equivalent modern airliners. No idea of the "revised" flight path of MH370 (like anyone else!) but it would appear possible that it did not impact (if it did) in the sea, but may have continued on a track that put it over some fairly inhospitable land terrain (Jungle/mountain). This would certainly pose more problems in the search. Just a thought! (As mine are with the NOK!)

[tvasquez]

As the days wear on, the issue of any debris drift does indeed become more and more of a factor. No one knows where the plane is, so I'm just putting this out there as a go-to reference in case something eventually turns up:

Real-time Navy model website for sea-surface temperature and currents:
HYCOM 1/12 degree page (http://www7320.nrlssc.navy.mil/GLBhycom1-12/INDIAN.html)

The Indonesian Flowthrough and Indian Ocean are the most relevant sectors. As a point of reference, 100 cm/s is equal to 1.9 knots, and 1.9 knots is 46 nm/day (EDIT: typo on 1.9, fixed, sorry). Most values are well below this.

Chart for the point roughly halfway between the crash and now, as a general reference since there is little day to day change:

http://www7320.nrlssc.navy.mil/GLBhycom1-12/navo/indianspdcur/nowcast/spdcur2014031018_2014031100_910_indianspdcur.001.gif

[mercurydancer]

BBC news are reporting that the Malaysians are stating that the Chinese satellite images are not related to the crash.

BBC News - Malaysia plane: China debris images 'not connected' (http://www.bbc.co.uk/news/world-asia-26559627)

Also interesting is that the Malaysians are joining with the Indian navy in searching the Andaman Sea, to the west of virtually all of the previous reference points.

Very interesting.

[jehrler]

GarageYears,

I believe that this particular T7 DID HAVE Satcom, just not the Satcom antenna per the recent Boeing AD. Not the same thing at all.

Could be but if so then, as hamster3null noted above, what is the

Boeing 777's satellite-communication link designed to automatically transmit the status of some onboard systems to the ground
??

Which systems would these have been since it seems that the RR one is not satellite based and earlier posts claimed neither was the ACARS?

If it did have such capability and these systems need to ping the satellites (even when not transmitting any data) ala a cell phone, then why has it taken this long for anyone to notice that these satellite signals lasted for 4 extra hours after the last communication?

[MG23]

If it did have such capability and these systems need to ping the satellites (even when not transmitting any data) ala a cell phone, then why has it taken this long for anyone to notice that these satellite signals lasted for 4 extra hours after the last communication?

I'm sure anyone who may have received a communication from the aircraft was checking their logs on Sunday, but any relevant information takes time to percolate through the investigation.

[Chronus]

Thanks Lonewolf 50. The reason why I posted this up was to show that the seasonal variation in the hydrodynamics of the region is such that by now the Malacca Straights would have revealed its dark secrets and that The Andeman Sea would have carried it well out into the Ocean.
But had I been a betting man I would put my money on the Indian Ocean.

[fox niner]

According to the RR engine ping communications, it stayed aloft for 4 hours. Not three, or five, but four. That is pretty exact information.
Actually, that is the most exact information I have seen for quite a while.

[Richard W]

An Iranian seeking asylum in Western Europe needs a visa in order to get to Western Europe. He's unlikely to get it if the Entry Clearance Officer suspects he will ask for asylum.

[wiggy]

if we ASSUME for a moment that, for example, racks E1-E4 at the MEC have been destroyed by a catastrophic event, with several electrical and other key system failures you'd have to be able to maintain trim and make pitch adjustments in a severely compromised cabin in terms pressurization.

Yep, that's why I'm struggling with the "MEC damaged,selectively and the aircraft flew for hours" scenario....

In fact I'm not really buying any mechanical/technical scenario I've heard so far ..I'm at a complete loss.

[clayne]

According to the RR engine ping communications, it stayed aloft for 4 hours. Not three, or five, but four. That is pretty exact information.
Actually, that is the most exact information I have seen for quite a while.

How about the exact information that shows the original WSJ reporter correcting their statement that it wasn't actually data related to RR engine monitoring?

[jehrler]

MG23,

I'm sure anyone who may have received a communication from the aircraft was checking their logs on Sunday, but any relevant information takes time to percolate through the investigation.

I understand but what seems to make this a bit of a long time to search is that, as noted in earlier posts, these communication devices have the equivalent of a MAC or IMEI address allocated based on the airframe.

This would, I imagine, make searching the logs much quicker as there would be an identifiable characteristic to a ping.

I also wonder if one can use triangulation or simply dead reckoning from the satellite(s) contacted to get a feel for where the aircraft went.

[flash8]

Would it be possible to bring an "all frequencies" jamming device on board powerfull enough to jam GPS/SAT/GSM/transponder etc.?

Yes, a commercial fairly easily available (although likely some flags would be raised) wideband RF Jammer with the sort of power needed would fit into a smallish suitcase, size in most cases here is proportional to power output and frequency range required.

[MG23]

I understand but what seems to make this a bit of a long time to search is that, as noted in earlier posts, these communication devices have the equivalent of a MAC or IMEI address allocated based on the airframe.

It still has to be validated, then passed on through the correct channels. That takes time.

Imagine if someone spoofed a signal, the people receiving the signal didn't validate it, announced it immediately, and that drew the SAR effort a thousand miles away from the real site. Not a good idea.

[V-Jet]

Interesting thing with hypoxia, and in pass this on to all who haven't done a chamber run, YOU FEEL MUCH WORSE POST HYPOXIC WHEN YOU GO BACK ON OXYGEN!

Thanks VR, and IW. All these years and I never knew! I can certainly attest to feeling like absolute crap at 0300 body clock time. You will not be performing well. Well enough, usually. But could easily part explain 'dumb' decisions/recognition at the start of procedure and the comment above lack of comprehension/ability if you regained consciousness prior to any impact.

IF there are 200+ pax sitting in liferafts somewhere they will be dying horrible deaths. I know ELT's etc should be activated but if not heard the results would be horrific. I would hope for the big bang/impact theory.

Decades of EP's training simply said 'no matter where you are you will only be in a raft for at most 48 hours' and the joke that (Qantas) the worst place to be would probably be just off SYD where you would be unlikely to get the worlds attention and would have to rely on local fishermen to get home is plainly a nonsense with some aircraft configurations.

[brika]

MAS/Boeing/RR all deny any engine maintenance data transmitted after 1:07 am, ie 1 hour after TO.

However, it appears that the a/c's maintenance troubleshooting systems continued to ping about once an hour - picked up by satellites - prompting US to head to the Indian Ocean to a position calculated at 5 hours flying time (no public data as to how many pings were transmitted).

Boeing/RR decline to comment.

Clearly, not every piece of data or a/c communication capability is in the public domain - for very good reasons.

WASHINGTON/PARIS, March 13 (Reuters)

Given that pings were detected upto 5 hours later, and given that these pings have to go through the antenna, it appears that the hull breach at the antenna site could not have happened.

[mseyfang]

As the days wear on, the issue of any debris drift does indeed become more and more of a factor. No one knows where the plane is, so I'm just putting this out there as a go-to reference in case something eventually turns up:


Real-time Navy model website for sea-surface temperature and currents:
HYCOM 1/12 degree page (http://www7320.nrlssc.navy.mil/GLBhycom1-12/INDIAN.html)

The Indonesian Flowthrough and Indian Ocean are the most relevant sectors. As a point of reference, 100 cm/s is equal to 1.9 knots, and 1 knot is 46 nm/day. Most values are well below this.

Chart for the point roughly halfway between the crash and now, as
a general reference since there is little day to day change:

Thanks for posting that. Most interesting. With respect to the part I bolded, I presume you meant to say 1.9 kts is 46 nm/day, correct?

[glitchy]

...why has it taken this long for anyone to notice that these satellite signals lasted for 4 extra hours after the last communication?This is engine-status VHF ACARS we're talking about, right? Satellite monitoring of VHF traffic is well within the realm of the possible, but the job is finding the relevant ACARS blocks in what's likely a mountain of noisy signals intelligence data, not to mention getting it approved for release.

I'm not at all sure the overall scenario hangs together, but if you want to speculate about a functional airplane, a deliberate transponder shutdown, and a quick descent to below ground-based VHF and primary radar coverage, having a satellite notice the engines trying to phone home makes some sense, and would also explain why RR never knew about it.

[answer=42]

@jehrler and others

If I understand correctly, the
Boeing 777's satellite-communication link designed to automatically transmit the status of some onboard systems to the ground
, presumed to be Satcom, pinged satellites for a duration of four hours, without actually transmitting any data.

Question:
Can you think of a scenario in which this satellite-communications link is severely damaged enough so that it does not transmit data but is not so severely damaged that it cannot ping?
Question:
Can you think of a scenario that produces the above outcome that does not involve manual intervention to cease data transmission, while not fully disabling the satellite communications link?

[Uncle Fred]

Indeed Ian.

For those of us who had to undergo periodic refresher training in the chamber, we realize that even though we were "taken" to altitude that it was all rather quick. It would be interesting to have a flight surgeon weigh in on what the recover would be if you were already at an 8000' cabin altitude for time (starting at 1 hour or so), the onset was insidious, fatigue, age, etc.

I agree in the chamber the recovery was quick. I just wonder if it would be so in the jet when it all came as a surprise and you then had to regain SA in short order to fly the jet.

Either way, thinking is quickly compromised.

[PlatinumFlyer]

"According to the RR engine ping communications, it stayed aloft for 4 hours. Not three, or five, but four. That is pretty exact information.
Actually, that is the most exact information I have seen for quite a while. "

I was under the impression that the pings lasted 4 hours, but that they only occurred every 30 minutes, so that the elapsed time could have been up to 4 hours and 29 minutes.

[tvasquez]

I just now saw my bonehead error. 100 cm/s = 1.9 kt = 46 nm/day. Fixed it.

[Coagie]

Jehrler: "If it did have such capability and these systems need to ping the satellites (even when not transmitting any data) ala a cell phone, then why has it taken this long for anyone to notice that these satellite signals lasted for 4 extra hours after the last communication?"


Jehrler, Even if an aircraft is equipped with satcom equipment to relay ACARS, it's a common mistake to assume, that it's communicating directly with a satellite. Instead, it communicates with a ground station, that relays it up to a satellite. Many areas don't have a ground station near enough to the aircraft, to get a good enough signal. Although technology exists, where commercial passenger planes could communicate directly with satellites, there's a lag in implementation, because it has to be tested to make sure it doesn't cause unexpected problems with other systems on the plane. Then standards have to be agreed upon, so it's usually a long time, between the time a technology comes into existence, and it's implementation on an airliner. Even changing the type of coffee maker in an airliner's galley takes years!

[Stuff]

MAS/Boeing/RR all deny any engine maintenance data transmitted after 1:07 am, ie 1 hour after TO.

Strictly speaking MAS/Boeing/RR deny that any data was received after 1:07am.

How about the situation where the aircraft was transmitting the engine data but no ground-station was available to hear it however the US surveillance satellites heard the aircraft trying to establish a link? Neither party is lying but it leads to the apparent conflict where one says nothing was received and the other says they heard a 'ping'.

[A33Zab]

But if we ASSUME for a moment that, for example, racks E1-E4 at the MEC have been destroyed by a catastrophic event, with several electrical and other key system failures you'd have to be able to maintain trim and make pitch adjustments in a severely compromised cabin in terms pressurization.

How much crippled will a T7 be when dual AIMS Cabinet fail?

It will loose communication (ALL?), displays (ALL?), navigation (ALL?).....and more.

[hamster3null]

I'd suspect, perhaps incorrectly, that a 777-200ER with an airline like MAS would more than likely be kitted with SATCOM.

Just because the airframe in question did not have a particular SATCOM antenna subject to an AD does not mean it didn't have one period.

I would also think the comm system would have to be "logged on" to ensure it was operational on demand.

How would an international airline maintain 'operational control' without SATCOM? VHF/HF voice-data only? Unlikely.

The best I could figure out, 777 has separate locations for SATCOM low-gain and high-gain antennas. MH370 did not have a high-gain antenna, which is why it was not subject to the "fuselage cracking" AD, but it could still have a low-gain antenna for the ultra-low-bandwidth Inmarsat Aero L protocol. It's totally possible that Inmarsat Aero L would involve exchanging periodic standby messages "in background", without anyone noticing. But this is all total speculation at this point and I can't find any concrete data on the exact hardware MH370 had onboard, or on the satellite protocol (that would most likely be proprietary anyway.)

[SaturnV]

The White House said the engines were still running four hours after contact was lost.

Obama administration officials later said the new information was that the plane’s engines remained running for approximately four hours after it vanished from radar early Saturday en route from Kuala Lumpur to Beijing
White House: Hunt for missing airliner may extend to Indian Ocean - The Washington Post (http://www.washingtonpost.com/world/china-satellite-spots-floating-objects/2014/03/13/72688034-aa68-11e3-b61e-8051b8b52d06_story.html)

[Una Due Tfc]

Coagie

Think you are wrong there. Full CPDLC coverage on the North Atlantic, most parts of which are well out of range of land based receivers. All done by satellite. Many carriers get re-dispatch messages etc out there

[jehrler]

glitchy

This is engine-status VHF ACARS we're talking about, right? Satellite monitoring of VHF traffic is well within the realm of the possible, but the job is finding the relevant ACARS blocks in what's likely a mountain of noisy signals intelligence data, not to mention getting it approved for release.

This scenario is the one that would seem to make the most sense for why it his taken so long to discover any pings past the loss of the transponder.

[narby]

Some things that I believe are "facts".

1) Engine/airframe data is sent via satellite, specifically the Iridium system
and 2) Iridium, being originally designed as a satellite "cell phone" system, would continually ping satellites, even if data wasn't being sent, or phone calls not made.

So even if Boeing, or the airline, or RR weren't getting data, that doesn't mean that the Iridium network doesn't have a good idea where the aircraft is, pretty much all the time. At least if the hardware was powered up. Even if they didn't have an active Iridium subscription, wouldn't the system keep track of the receiver, if only to be ready to give it a subscription code?

Cell phones ping towers almost constantly so as to maintain a connection in case a phone call is made. The system has to know what tower (or satellite) has the phone in view, so your phone can be made to ring within seconds of a phone call.

Lots of assumptions here, but some lights are coming on.

[bono]

SaturnV

Based on the Wall St. Journal reporter's accounts, the pinging lasted for four hours, at 30 minute intervals. So there was power and a functioning communication link during that interval. Depending on whether the U.S. can triangulate the location of each ping, that would give an approximate a location at the time of the last ping. That leaves up to a 30 minute flying distance from the point of the last ping.
According to the Journal reporter's radio interview, he mentioned several times that U.S. officials haven't ruled out the plane landing, or crash-landing on land.


This is beginning to look like either a sudden depressurization related pilot incapacitation or pilot initiated deliberate destructive action.

[jehrler]

Coagie,

Jehrler, Even if an aircraft is equipped with satcom equipment to relay ACARS, it's a common mistake to assume, that it's communicating directly with a satellite. Instead, it communicates with a ground station, that relays it up to a satellite. Many areas don't have a ground station near enough to the aircraft, to get a good enough signal. Although technology exists, where commercial passenger planes could communicate directly with satellites, there's a lag in implementation, because it has to be tested to make sure it doesn't cause unexpected problems with other systems on the plane. Then standards have to be agreed upon, so it's usually a long time, between the time a technology comes into existence, and it's implementation on an airliner. Even changing the type of coffee maker in an airliner's galley takes years!

If that is true that is very interesting as it means that calling these SATCOM is really a misnomer. It also makes me wonder why this would be a useful addition for ETOPS aircraft as they would seem to spend a fair amount of time over open and base station free areas?

I just assumed (yes, I know) that when someone discussed SATCOM they were discussing an iridium like service (with the attendant high high costs).

[tartare]

It is an entirely plausible scenario that US SIGINT satellites picked up ACARS data or any other electronic emission from the jet - and that they are only now working that out.
They can monitor signals as weak as a hand held walkie-talkie from orbit.

[Coagie]

Una Due Tfc:
"Coagie

Think you are wrong there. Full CPDLC coverage on the North Atlantic, most parts of which are well out of range of land based receivers. All done by satellite. Many carriers get re-dispatch messages etc out there"


Una Due Tfc, I Hope you are right. I checked into it how airliners used satcom 4 years ago, so my info is dated. Wow, has it been 4 years? Time passes quickly as you get older. 4 years used to seem to me like centuries! Now, 4 years ago seems like last weekend!

[dicks-airbus]

No cargo manifest yet... anyone something on it?

[Backseat Dane]

It's one thing that Amelia Earhart could vanish without a trace over the Pacific some 77 years ago - but a modern airliner carrying 239 souls in this day and age? (And no matter where, really)

Doesn't it raise the question of mandatory GPS tracking equipment on board all aircraft flying on routes where they will be travelling in airspace not covered by SSR? Or to keep it simple and stupid: All airliners certified for commercial operation?

The bandwidth needed for transmitting what would at the most be an SMS containing the A/C registration number, altitude, speed OTG and coordinates maybe every 2 minutes isn't prohibitively expensive. I'd suspect the cost of this one search for MH370 could pay for the whole shebang for quite some time.

This equipment would have to be somehow NOT connected to the rest of the aircraft's avionics and have an independent back up power supply so as to
be able to operate for ex 5 hours on its own.

It could be jammed of course but at least that would leave the world with a last known position and the knowledge that someone was actively working against being tracked.

[jehrler]

One further bit of "evidence" for the VHF engine monitoring signals being picked up by NSA satellites is that the reporting and the white house both specifically mention that the engines kept running.

If this was just normal satellite pinging being identified then why would they mention the engines running?

However, if the RR VHF transmissions were being picked up by the NSA then they could actually see that the engine diagnostics were the ones doing the pinging and, presumably, they only do that when powered up.

[Una Due Tfc]

Indeed, and depending how detailed the diagnostics RR received(ie what angle the variable rotors and stators are at) they would have a rough idea of what altitude the aircraft was at when the data was sent

[papershuffler]

(Apologies if already covered.) If the 'pings' were still regular, does that suggest that nothing had malfunctioned on board, i.e. it was reporting as per any normal flight? (That would indicate that conversely, irregular pings would signify an event such as AF447.)

Or is it that the aircraft only attempted to make contact/a report every half an hour?

[OleOle]

MH Experience - Fleet - Boeing 777-200 | Malaysia Airlines (http://malaysiaairlines.com/hq/en/mh-experience/our-fleet/boeing-777-200.html)

Business Class
...
Other features and facilities include a light preset 10 minutes massage, an in-seat power outlet for PC and other personal electronic devices, a 10.4-inch touch screen TV, satellite telephone and LED reading light.


This is a strong indicator Malaysa has SATCOMM on board its 772. Their ACARS just doesn't seem to be configured to use it. Whatever equipment they use (inmarsat iridium thuraya etc...) normaly there would be some kind of keep alive protocol between airborne transceiver and the communication satellite. With iridium there is also a cell phone like handover between the satellites.

[krakenC2]

Claybird

For a practical example of "cause and effect" and to offer some professional example to illustrate the effect of both explosive decompression, the resultant hypoxic cabin atmosphere, with measured internal systems damage, and a resultant rapid depletion or remaining flight crew oxygen reserve.

You only have to consider a simple 10 litre oxygen flight crew reserve cylinder at 150 bar pressure exiting through the aircraft skin with the equal and opposite reaction of the cylinder valve exiting up into the passenger cabin causing additional damage and the required decompression leak path.

If in addition the oxygen release were to act with an ignition event, the "fire triangle" of adiabatic heat with a fuel source (metal material etc ) together with the oxygen acting as a fuel you have the basics of an oxygen plasma fire.

The photos below illustrate this with Boeing 747-482 (VH-OJK) Manila Philippines 25 July 2008 just the mechanical explosive damage without a resultant fire of one of the high pressure oxygen reserve cylinders in the forward hold section of the B747

If of interest detail and engineering can be discussed in detail but it does illustrate clearly causation effect.


http://i1311.photobucket.com/albums/s664/fowke1/fig_17_zps04a4df7d.jpg (http://s1311.photobucket.com/user/fowke1/media/fig_17_zps04a4df7d.jpg.html)

http://i1311.photobucket.com/albums/s664/fowke1/fig_10_zpse0d6eec1.jpg (http://s1311.photobucket.com/user/fowke1/media/fig_10_zpse0d6eec1.jpg.html)

http://i1311.photobucket.com/albums/s664/fowke1/fig_09_zps6df7a4a2.jpg (http://s1311.photobucket.com/user/fowke1/media/fig_09_zps6df7a4a2.jpg.html)

http://i1311.photobucket.com/albums/s664/fowke1/fig_01_zps9a75b361.jpg (http://s1311.photobucket.com/user/fowke1/media/fig_01_zps9a75b361.jpg.html)

[jehrler]

So does the monitoring system actually send current status between engine status changes?

The impression I got from earlier posts here was no...that the only time they actually report data is when the engines have significant mode changes and/or there is some parameter that goes beyond a critical threshold.

If my impression is correct, then it again would be consistent with the original WSJ reporting. They know the engines were running and stayed running but don't know anything about their condition or power status, etc. That then gives them the 4-5 hours of continuous flying at some speed, altitude and direction.

[wdowell]

Thanks to all contributing in a meaningful way to this incredible situation!

It would seem to me inconceivable, after 911, with all the money thrown at trying to mitigate risks etc, that NRO/NSA etc don't have programmes to monitor aircraft movements around the world (and I don't mean through fr23!) - they mandated secure cockpit doors against threats of hijacking but didn't have policies on place to know the whereabouts of an aircraft with it's comms switched off?

I suspect we are now in a phase of the US and others quietly leaking/pushing the Malaysians and others into finding this thing with hints , clues etc as they replay and analyse their satellite swoops (hint the indications today). Completely agree that the likes of china and the us won't be in a rush to reveal their abilities but you get to a point that this starts looking so bad it's unreal!

If this plane did somehow land all in tact what in earth could be the point? To fly it somewhere into something? In which case you could just do that in the first plane on a scheduled route.

If the plane was intended to crash, why turn off comms? Surely a terrorist attack is only "effective" if it's publicised. Or is this the ultimate riddle to show how things aren't in control?

Is this a hijacking gone wrong? They turned off stuff then the pilots created hypoxia to trh and incapacitate the jackers, but then crash into the sea (North) 4 hours later?

First change that will happen after this calms down: live, "tamper proof" blackbox feedback. And I suspect those passport databases will be getting checked a bit more too (even if in his case they they turn out to be irrelevant)

[VinRouge]

What system are other non essential transmitting systems powered off (radalt etc) Guessing not the emergency and battery busses.... If your engines are running, your idg's obviously have to be running. Acars isn't the only way of determining engines on/off status I suspect.

[flash8]

How is the engine data transmitted?

Does the Engine send data via one of the ARINC buses to a RR decoder/transmitter device in the bay and then to an existing antenna for onward dissemination?

[James7]

flash8 How is the engine data transmitted?

Does the Engine send data via one of the ARINC buses to a RR decoder/transmitter device in the bay and then to an existing antenna for onward dissemination?


Usually it is through ACARS either via Sat, VHF Data, or HF Data. Maybe this aircraft had its own antenna.

[SaturnV]

If the new search area is now to the northwest of the Strait of Malacca, into the Andaman Sea, the plane had to change its heading.

The Malaysian authorities stated it was last observed on their radar near Palau Perak a small island, at the top and middle of the Strait, located west northwest of Georgetown on the west coast of Malaysia. Palau Perak is west southwest of the position when the transponder signal was lost. If it did not change its heading, the plane would overfly northern Indonesia, the province of Aceh, devastated by the tsunami.

So if you have engines running, communication link still functioning, and a change in heading.....

[1a sound asleep]

White House: Hunt for missing airliner may extend to Indian Ocean - The Washington Post (http://www.washingtonpost.com/world/china-satellite-spots-floating-objects/2014/03/13/72688034-aa68-11e3-b61e-8051b8b52d06_story.html?tid=pm_pop)

One senior administration official said the data showing the plane engines running hours after contact was lost came from the Aircraft Communications Addressing and Reporting System, or ACARS, a way that planes maintain contact with ground stations through radio or satellite signals. The official said Malaysian authorities shared the flight data with the administration.

[Ngineer]

One senior administration official said the data showing the plane engines running hours after contact was lost came from the Aircraft Communications Addressing and Reporting System, or ACARS,

Are they suggesting ACARS was operational but the only thing transmitted was engine data? Strange that the airline did not report this.

[NavyDude]

If the a/c flew to Pulau Perak, then it flew right above Langwaki International Airport. No detection by radar ?

[Rain dog]

How many runway options are there for a B777 on the Andaman and Nicobar Islands?

[rigbyrigz]

re: "And you go to Car Nicobar????"

not at all likely, since India is deploying SAR assets from that airport, Washington Post quote below:

"Indian coast guard and navy aircraft were also pressed into service from a base on the Andaman and Nicobar Islands. A senior Indian official said late Thursday that a total of three ships, two planes and a helicopter have now been dispatched in the growing search effort."

[redmin888]

Re-post 2968

There is no access to E&E bay from the flight deck. Two-Thirds of CBs are located in the E&E bay including the Sat Com CBs

But then different airlines different configurations as to location of sat com cbs

[tdracer]

How is the engine data transmitted?

No FADEC (at least on Boeing) has it's own downlink capability. Engine data is sent to the airplane over ARINC 429 (in the case of the 777) where other systems (e.g. ACARS) downlink and/or store the data.
Assuming Engine Condition Monitoring reports were actually transmitted, I'd expect them to include altitude, airspeed, and total temp in addition to the actual relevant engine data. Lat and Long would not typically be included in ECM downlink.
Useful data as to the location of the aircraft when the report was transmitted probably not be in the data set itself, but might be obtained from the downlink path (e.g. what station or satellite received the data).

[VinRouge]

Already stated, there are other ways of determining engine running status other than via acars....

[oncemorealoft]

There is so much utter tosh being spouted about what data was sent from this aircraft I'm not surprised that most truly professional pilots have packed their bags and left this thread long ago!

As an ex-employee of an airline that actually used this facility let me try and explain how this generation (mid to late 90s) actually works. I'm not an engineer so fine detail may need some correction from genuine experts.

Data snapshots of engine parameters are sent, depending on how the airline has set up its support package, either directly to Rolls Royce or via the airline. This is done via ACARS using, typically, VHF radio link, though via satellite if specified. which for this generation of aircraft is unlikely.

Usually, these snapshots are taken and transmitted in near real time for Take-off climb and cruise. If the aircraft is out of range, the information is stored and transmitted once a suitable ACARS link is re-established. There was a New Scientist article being referenced yesterday by many media that stated that Rolls received two such data bursts: Take off and climb before ACARS link was routinely lost. Comments by the Malaysian defence minister and Malaysia Airlines CEO at Thursday's media briefing would fit into this stating that the last data was received just after 0100 local - well before contact was officially lost and less than 30 mins after take off.

All the airline and engine manufacturer expects from this generation of engine is time-stamped data on temps, pressures, shaft speeds, fuel flow, mach number etc.. Not where the engine is.

Such data would routinely be passed on to investigators and involved parties in the event of a serious incident or accident. If an official investigation was underway or anticipated, then this info could only be made public via the investigating authority.

[Xeptu]

"perspective people" What should be glaringly obvious by now is that Malaysia have no dedicated maritime search and rescue capability. A situation I'm sure will change after this event.

MH370 has crashed, probably due to a fire or some other catastrophic event. It will be located within 300 miles of it's last known position, the closer it is to that position the more embarrassing it will be. The debris field should be washing up on coastal beaches in the next couple of days.

Patience, it will be found, That is a certainty.

[rigbyrigz]

ABC News now reporting; systems were shut down at different times, indicating not a catastrophic or mechanical failure as much as a human being decision.

[Bloxin]

I noted your original post saying that the crew O2 bottle fittings were on the aft side of the bottle and thought that the the wind was blown out of my hypothetical sail.

However. I have done some more research on the QF30 incident and found in the Australian Transport Safety Bureau report that the bottle was propelled upward through the cabin floor where it damaged a door handle and some trim, then dove back through the hole in the floor and exited the aircraft via the hole in the fuselage... RUBBISH??? Thats what I thought.

However. There is a photo tab on the web page. The last photo of the set is of an O2 bottle sized hole in the floor panel directly above the hole in the fuselage.

The Pax O2 bottles in the 747 fwd cargo sidewall stand vertically, plumbing on top, so the base end must have failed.

The missing bottle was not found onboard.

Ref: Australian Transport Safety Bureau website

Side Menu: Aviation safety investigations and reports

Search: July 2008 and QF30 is top of the list

All... My hypothetical structure of events is purely speculative, as most here are, until we get some real facts to work with.

Thank you. Blox in.

[BARKINGMAD]

It's really quite amazing to see all this idle speculation and contemptuous remarks about the perceived inability of the local radar facilities to track this one (assumed) primary track with any degree of success.

Your memories are obviously too short to recall that the 9/11 Commission concluded that the worlds richest and most technologically advanced country was unable to track and intercept FOUR allegedly primary returns over the US mainland on that fateful occasion.

Can we stop this racist and arrogant discussion right now and, with a little humility, accept that such tracking capability is most unlikely to be operating/available in the affected region?!

And the idea that a T7 will impact the ocean and hide itself in the sand/silt like a stingray is indicative of the febrile imagination of some of our posters and leaves me in despair about our profession, if indeed these fantasists are Pro pilots??!!

[CommanderCYYZ]

Perhaps I've missed something,please forgive me if I have. However, my understanding of ACARS TX'd from MAS 370 is that there was none. So why are so many people postulating what can be inferred from the TX'd data?

My understanding:

Malaysian Airlines said there was no communication from the AC after contact was lost.

Boeing said that no data was received from the AC after contact was lost.

RR has said the no data was received after contact was lost.

US sources have said that the AC may have flown for 4 hours after contact was lost. They suggested that this was because satellites received "faint pings" from the AC's monitoring system after contact was lost. However, they also clearly stated that "no data was received from the AC."

So again, I ask; Am I missing something?

[EcamSurprise]

Maybe the plane did experience technical difficulties, Turned around to return to KL and was shot down....maybe the technical problem meant it lost comms and it was unable to relay that it was a civilian plane with problems...not good pr for the Malaysians

There are a large number of loss of comms incidents all around the world everyday and there are procedures that are followed in these cases.
Sometimes this could escalate to aircraft being intercepted.

However, there are guidelines for being intercepted and it doesn't result in an aircraft being shot down with no special reason.. (unless someone is very trigger happy).. YouTube the video of a Vueling being escorted into Ams (I think) after being intercepted. Yes, he got escorted but he didn't get shot down as he complied with the instructions of the interceptors whether that be via radio or via lights / wing signals.

So sorry.. but that just doesn't make sense.

[c52]

What benefit is it to the investigators to publish what the cargo was? - None, so they won't publish it.

[saffi]

"no data was received" does not mean there was no contact.... There could have been a "handshake", but no data received. Semantics...

[just Mal]

just tried google's gps tracker and got a response including coordinates>
I am not sure what this is showing, - just the last known position or something More?

I APRS object MH370 - show graphs
Map loading...
Source callsign: K7GPS-3
Comment: Initial last ctc of B-777. Where is it?
Location: 7°33.55' N 103°42.63' E - locator OJ17UN54GE - show map - static map
Last position: 2014-03-13 23:00:11 UTC (11m19s ago)
Last path: K7GPS-3>APU25N via TCPIP*,qAC,T2QUEBEC
Positions stored: 1
Others sourced by K7GPS-3: Balloon IRLP-7844

[OlaM]

Are there any good ideas as to why this misunderstanding about 4 hours of ACARS data could arise? Is there some system in the middle, such as the airline's server or the satellite account logs or anything like that, which could show what looked like activity from the aircraft even though the aircraft did not send data?

Very trivial example: I can die at 4 o'clock and two hours later someone can see an ad on Facebook with my name being listed as "OlaM likes Boeing 777s" time stamped 6 o'clock- it seems like an act done by me after death, but it's really done by a computer.

Less trivial example: You purchase something on your credit card March 8. You die on March 9. Your statement says you paid for it March 10. Bought by a ghost? No, March 10 was the first business day after Saturday the 8th.

It seems this case is plagued by random statements made by ill-informed or misunderstanding personnel to crazed reporters and the hurtful conspiracy effects will linger for a long time. So what about ACARS can be misunderstood in a way that makes you think the plane flew 4 hours longer than it did?

[Lonewolf_50]

So what about ACARS can be misunderstood in a way that makes you think the plane flew 4 hours longer than it did? The answer to that is best posed to whomever in the US of A released that info to the media. I suspect they not wish to tell you, citing "methods and sources" but a brief explanation has already been provided in this very thread. Less than ten pages back.

We don't have to buy it, nor believe it, but it's there.

[GlobalNav]

@CommanderCYYZ

Others have addressed your question a few times, but to recap: the satellite radio system "pings" the satellites to maintain contact even without sending otherwise useful data. So, by saying in effect "Here I am, are you there?" repeatedly, the system is ready, the satellite is known, etc., for when real data communication is needed.

So the reports that no additional engine data was sent can be true, along with the 4-5 hours of "pings".

[CommanderCYYZ]

The thing is, there was no data TX'd. What appears to be the case, according to reports, was that ACARS system on the AC was sending RTS pings periodically but never connected. The reason given was that MAS don't pay for that level of monitoring, so it was reported. However, the "pings" would seem to suggest that the AC was still alive 4 hrs after contact was lost.

[tdracer]

Boeing said that no data was received from the AC after contact was lost.

RR has said the no data was received after contact was lost.

Correction - Boeing and RR declined to comment on the reports that no data was received. Which is per process - Boeing and RR are effectively under a gag order and will not comment on the investigation.

BTW, passenger oxygen is good for ~15 minutes. Crew oxygen somewhat longer than that.

[jugofpropwash]

What benefit is it to the investigators to publish what the cargo was? - None, so they won't publish it.

As I recall, cargo information has come out quite quickly on some occasions in the past. I distinctly remember it coming out that Ft 800 was carrying a large quantity of glitter, of all things.

[jimjim1]

Here are what now seem to be almost facts.

The ACARS system for the airframe did not have a satellite subscription.
The ACARS system for the engines did have a satellite subscription.

The satellite path is used when there is no VHF path available.

The engine ACARS only sends when a significant event takes place. There was no event after the top of climb and so no further messages were sent.

The Engine ACARS satellite coms system "pings" the satellite every 30 mins.

Therefore:- Since about 8 pings were received and logged the engines ran for a further 4 hours after last message at top of climb since a shutdown would have resulted in an ACARS message. The exact time is not known of course.

By the way. I am far from satisfied that the satellite system used is Iridium. Due to the low earth orbit and rapidly changing overhead satellites I would have thought that the ping might need to be more frequent.

[PilotsResearch]

General aviation aircraft have been doing this for years. I know of at least 3 vendors who offer such service at modest cost: Spidertracks, Spot, and InReach.

Basically, a unit on the a/c sends its GPS coordinates every 10 minutes or to so a satellite which relays it to the tracking company's servers.

The airborne unit often goes on the glareshield, and it includes its own battery that lasts for a few hours if power is lost.

[opsmarco]

Well, since a lot of people here doesn't seem to understand what's going on regarding the ACARS/SATCOM stories in the press, let's recap what's going on regarding the new information from the US.

- MAS ACARS comms only work thru VHF since they chose not to pay for the extra fee for ACARS SATCOM link
- That 777-200 is SATCOM equipped
- What was found by US Government services (NSA, or maybe they asked Iridium directly to check the logs) is that, since the a/c ACARS system was out of VHF coverage, the system tried to connect thru SATCOM. But since MAS doesn't have a contract for that, connection was rejected, but remains a trace in their logs.
- That means that what they actually found is the log indicating every time the aircraft ACARS system tried to log in thru SATCOM and failed due to the lack of contract for that. Since the ACARS system onboard that specific aircraft tried for 4 hours after its disappearance to connect via SATCOM to the ACARS network, it means the aircraft was, at least, powered on and, since not found anywhere yet, probably flying.

Sorry if I wasn't clear enough, I tried to write everything down ASAP...

I have an IT background, and according to all the available sources, this is my interpretation of what's going on.

[Golf-Mike-Mike]

Correction - Boeing and RR declined to comment on the reports that no data was received. Which is per process - Boeing and RR are effectively under a gag order and will not comment on the investigation.


Agreed, and I believe the official line at today's press conference was to say that reports to the contrary were "inaccurate", not that they were wholly wrong. Hence (my deduction) the interest now in the Indian Ocean.

[nike]

Malaysia Airliner Communications Shut Down Separately: US Officials Say - ABC News (http://abcnews.go.com/m/story?id=22894802&ref=http%3A%2F%2Ft.co%2FuPTMYNU5Z1)


"We have an indication the plane went down in the Indian Ocean," the senior Pentagon official said.


The above statement would normally be taken as fact. But to date, almost every similar (definitive) statement has been discounted.

Enough of the secret squirrel stuff. We seem to have several statements from sources that usually are reliable being refuted everytime by the Malaysians leading to this never ending merry-go-round.

Now, if the Malaysians are correct, why are these sources intent on providing mis-information?
Again, sources that you would normally associate with being reputable.

[jehrler]

Well, since a lot of people here doesn't seem to understand what's going on regarding the ACARS/SATCOM stories in the press, let's recap what's going on regarding the new information from the US.

- MAS ACARS comms only work thru VHF since they chose not to pay for the extra fee for ACARS SATCOM link
- That 777-200 is SATCOM equipped
- What was found by US Government services (NSA, or maybe they asked Iridium directly to check the logs) is that, since the a/c ACARS system was out of VHF coverage, the system tried to connect thru SATCOM. But since MAS doesn't have a contract for that, connection was rejected, but remains a trace in their logs.
- That means that what they actually found is the log indicating every time the aircraft ACARS system tried to log in thru SATCOM and failed due to the lack of contract for that. Since the ACARS system onboard that specific aircraft tried for 4 hours after its disappearance to connect via SATCOM to the ACARS network, it means the aircraft was, at least, powered on and, since not found anywhere yet, probably flying.

I think that is reasonably accurate but for one item.

It is possible that NSA satellites detected the VHF pings by the ACARS/RR systems, not any attempted satellite pings.

Your summary assumes the pings were for satellites rather than VHF ground stations.

You may be right, but it seems to make more sense for it to have taken this long because NSA needed to sort through many, many radio events rather than just look at satellite logs.

YMMV.

[JanetFlight]

What really puzzles me its the Myanmar Theory...i've been there, as well some friends presently working based there, and its not anymore the typical "007" country movie with vast jungles full of places where u can build a new rwy, or already use an old one constructed, without being noticed. Even if we can land and stop it in 1300 mts, the handling to support it and after that hidding it among the jungle its not a so easy task, more naive and "Hollywoodesque" than all the rest, me thinks.

[Wantion]

"since the a/c ACARS system was out of VHF coverage, the system tried to connect thru SATCOM"


Are you sure it only tries to ping/connect if out of VHF Range ..?


...I thought I had read that it pings the SATCOM all the time.

[OlaM]

Thanks opsmarco! I trust that is based on practical experience with how ACARS hardware and satcom accounts are handled. If so, it begs another question, how much hardware can survive an ocean impact and still transmit?

[UnderDriven]

- What was found by US Government services (NSA, or maybe they asked Iridium directly to check the logs) is that, since the a/c ACARS system was out of VHF coverage, the system tried to connect thru SATCOM. But since MAS doesn't have a contract for that, connection was rejected, but remains a trace in their logs.
Would the VHF system broadcast to try to establish a connection before trying SATCOM, or is the VHF system somehow aware of being out of range without having to broadcast?

[deadheader]

Civil Aviation Chief Azharuddin “There are some things that I can tell you and some things that I can’t.”


Federal CID director Comm Datuk Hadi Ho Abdullah "The police will divulge the latest development in the case at the right time"


Minister in the Prime Minister’s Department Datuk Seri Shahidan Kassim confirmed that he will be flying to an undisclosed location “You will have to wait for the official announcement”


Unnamed Chinese govt official "Malaysian authorities are deliberately concealing information"


>


Given evidence emerging of at least two changes of heading after the comms black out and engines running for sometime, it is too early to rule out darker explanations IMV...

[mm43]

@CommanderCYYZ
What appears to be the case, according to reports, was that ACARS system on the AC was sending RTS pingsOn the balance of probabilities, the ACARS had been disabled, but the SatCom system was alive and handshaking periodically with a selected satellite.

[opsmarco]

Not that strange : the same happens if you place an old, inactive sim card in a mobile phone. Your phone will keep trying again and again to connect to the network, despite previous rejections. Same with a router at home, once you resigned your internet connection : machines will try again and again to connect, since the error can be due to a temporary problem in the network.

Regarding specifically the ACARS system, I suppose there's a way, thru maintenance pages, to change that, but only a certified 777 engineer will be able to confirm that.

[FIRESYSOK]

I find it very hard to believe that the ACARS system on Malaysia aircraft do not have SAT connectivity.

What is most likely is that MAS does not subscribe (pay) for airframe status monitoring. That requires a lot of bandwidth that they've determined are not worth the extra cost.

OOOI/weather/free text are probably all available to the pilots when the ACARS is using the VHF *and* SAT medium. Additionally, the RR health monitoring is probably paid for by RR and/or MAS as part of the purchase/warranty programme and does transmit via satellite, but only when programmed or demanded.

Snapshots of engine parameters are taken and sent at pre-programmed intervals or whenever something is out of tolerance. What that programming is is known to the engineers.

What the WSJ got wrong was that the Inmarsat network detected "pinging" from the Satcom system itself, not the RR trend monitoring data.

[OPENDOOR]

Many posts ago somebody stated that their cell phone had received three texts welcoming them to a country that the aircraft they were in had transited at FL330

If this occurred it would have required a “handshake” signal exchange between the phone and mobile network operator.

I can’t help wondering if those coordinating the SAR effort have considered cross referencing the mobile phone numbers of all on board with every cellular network that flight MH370 could conceivably have over flown?

[opsmarco]

MAS officials said that since the question was asked during a press conference (don't remember which one), and that info has been quoted here also (maybe 80-100 pages(!!!) ago...) : They only have ACARS access thru VHF, not thru SATCOM.

[Heli-phile]

Has there been any disclosure of the fuel uplift on this flight (Max endurance possible)
Assuming centre tanks were selected first, at what point would centre tanks have to have been deselected (before contact was lost or after?)

[FIRESYSOK]

How do MAS pilots get weather, etc. enroute when over oceans? Wait for VHF? I find that hard to believe- it's a global airline. If true, it says a lot about the operation in general.

[redmin888]

Re: post 2957 Dual AIMS failure

Systems affected are
CMCS(maint computre, faults reporting etc),
ACMS & ACMF(processes all engine, air and adiru data, etc and feeds relevant data to their relevant systems ),
EICAS and EFIS displays (Left with only basic Standy-by) ,
24bit aircraft address,
FMCS (Flight management etc)
TMCF(thrust management)

[opsmarco]

I find it hard to believe too, but I assure you I remember perfectly that info since I thought it was very surprising for such an airline.

And Radio ears, e-mails and internet connection go thru a different system (such as On Air, or the former Connexion by Boeing).

[xcitation]

Seems like a strange way to go about it. Possibly 1000's of plane pining a satellite for no reason & being denied due to lack of contract. Surely it would just be disabled onboard to save wasting resources.

Strange to who? Others have use for that data. It is well documented that cell phones continue to send pings, printers print microscopic dot codes on every page, photos include dot codes on every image so apparently someone involved with the manufacturers has a use for this information. The power required to send a few bytes of ping data an hour is negligible given the power available on aircraft.

[kaikohe76]

It's easy to sit back & be critical of all the various agencies presently involved with the search for the B777, but to me it does appear, the Malaysian Authorities are well out of their depth. There appears to be a division of action & responsibility between both the Military & Civilian sections. Each agency is giving out conflicting information & both seem to be more interested in saving face, I would suggest. We have some senior Malaysian Military Officer totally adorned with ribbons & various insignia, standing up & saying very little indeed, this may well be just waving the Military flag. Civilian spokesmen, of which there are many, also seem to be there, just in order to make their presence know. At this stage, all of the local authorities appear to be running about , but doing little & achieving less. All this demonstrates, that the local agencies in Malayisia, have absolutely no idea of what happened to the missing 777 & where it is. Why not just come out & say this?

[simon43]

How do MAS pilots get weather, etc. enroute when over oceans? Wait for VHF? I find that hard to believe- it's a global airline. If true, it says a lot about the operation in general.
They would use HF ACARS (link to a list of HF ACARS ground stations is here:

HF ACARS (http://www.blackcatsystems.com/radio/hfACARS.html)

As posted earlier, the nearest F ground station is at Hat Yai (south Thailand).

They would also use HF voice comms for weather reports etc.

A link to a list of HF aeronautical stations is here:

http://www.canairradio.com/hf.html (http://www.canairradio.com/hf.htmlhttp://)

For the region of interest, there are HF ground stations at KL, Singapore, Bangkok etc.

[flt001]

Strange to who?

My understanding on satellite technology is that anything you do is incredibly expensive. You don't do anything unless there is a reason for it.

Pinging a satellite which then logs and downlinks this data (again x1000's planes 100's times a day). A satellite which will not respond under any circumstances has no point. A simple off switch in the software onboard would be the most logical way to perform this rather than a credential check via satellite using up bandwidth from the plane to the ground base to the satellite back to a ground base and then onto IT HQ and back again.

Now maybe this pinging leads to results but that isn't by design.

[FIRESYSOK]

Simon43,

Thanks. Had no idea HF ACARS would be used by an airline such as this.

[PilotsResearch]

Your understanding has gone out of date. Smartphone plans over satellite now have costs similar to what we paid for cellphones a decade ago.

I'm told by a friend in the business that the satellite industry has surplus capacity, and companies are out beating the bushes to find new users.

[Evey_Hammond]

Even more to the already-long tale. The question is: deliberate or not?

"KUALA LUMPUR, Malaysia -- Two communications systems on board the missing Malaysian Airlines plane were shut down separately, CBS News confirmed Thursday, a development that suggests the systems were deliberately turned off.

CBS News correspondent Bob Orr reported the two systems used to track Flight 370 were shut down sequentially, just before the Boeing 777 apparently changed course and turned west.

While that could suggest a deliberate act, CBS News aviation and safety expert Capt. Chesley "Sully" Sullenberger cautioned that it is "conceivable" that the communications systems could shut down sequentially on their own in the event of a catastrophic electrical failure. He said the systems in a plane are so compartmentalized that things could shut down in a cascading, domino fashion instead of all at once."

Full story here (http://www.cbsnews.com/news/communications-systems-aboard-malaysian-jet-were-shut-down-separately/)

[Ollie Onion]

I was just reading a report on CNN that states that MAL 'DOES NOT' subscribe to the ACARS aircraft monitoring so no data was uploaded during the 4 hour period. But it did also say that even if the airline does not subscribe to the ACAR's Satcom service the aircraft will still ping the satellites and establish contact because that is how the 777 system is designed, the fact that MAS doesn't subscribe does not effect that. It is these 'pings' that they have now found to have carried on for 4 hours after last contact and they apparently will only happen whilst the aircraft is powered with engines running. The report also said that the aircraft could be airborne on land or indeed just flying around in circles.

[Communicator]

There seem to be three separate issues in connection with ACARS that MAS senior management has been unclear about:

1. Human Messaging through ACARS

When MAS talks about ACARS, they are probably viewing it from a layperson's perspective: No HUMAN OPERATOR received/sent any messages through ACARS.

2. Automatic Messaging through ACARS

It seems that some system status information was successfully sent to Rolls Royce and to Boeing, presumably through ACARS. These transmissions occur only when triggered by specific conditions (e.g. engine start/take off). It is not clear when the last transmission from MH370 was received.

3. ACARS Link Establishment

Apparently, the ACARS Satcom "pings" a satellite at regular intervals (hourly?) to establish contact and download incoming messages (if any). Unless messages are actually sent or received, this link establishment or "ping" information would only be available to the ACARS system operator, NOT to MAS, Rolls Royce or Boeing.

Ollie Onion's post above indicates that Satcom "pinging" would occur even though MAS may not have subscribed to the Satcom options for ACARS.

It seems that U.S. Government statements were referring to these Satcom pings, NOT to full messages. (Of course, anyone familiar with the detailed workings of the system would have tried to ascertain the ping log on Day 1.)

NOTE: Similarly, there has been no official recognition of the potential that cell phones left active established contact with ground-based cell towers if/when the plane crossed peninsular Malaysia (and Sumatra). Also, ADS-B messages may have been received by ground-based stations in those areas beyond those evaluated by FR24. All this would be of a piece with the apparent failure to check primary radar recordings at an early stage.

[TheShadow]

If there had been, you might conclude that a well thought out cockpit-driven "total disappearance event" may have given a disabling of that non-essential bus feeding the rear areas a high priority. They'd not want the pax emailing their concerns to anybody (such as a locked cockpit door). But if MAS were too cheap to maintain a satellite ACARS contract, they'd likely also not offer their pax inflight internet access. Organic IFE is much cheaper.

Why would a "total disappearance" be a priority to someone? You have to conclude that the eventual lessons of Silkair and Egyptair's MS990 was that any relocatable wreckage would always give up the facts of the accident. A solution to that would be to place the aircraft beyond the search parameters and in water too deep for recovery of DFDR/CVR. That's the Indian Ocean, not the South China Sea/Gulf of Thailand.

But the additional puzzle might be that there should be no in-cockpit or avionics bay methodology for disabling an Emergency Locator Transmitter (E.L.T.) or stop it transmitting to a SAR satellite on 406MHZ. This jigsaw is missing a few pieces.

[grumpyoldgeek]

"There is probably a significant likelihood" that Malaysia Airlines Flight 370 is on the bottom of the Indian Ocean, a senior U.S. official told CNN's Barbara Starr Thursday, citing information Malaysia has shared with the United States."

And I submit that there is a significant likelihood that US subs or subhunters have picked up the underwater ping from the emergency locator transmitter.

If so, expect a breakthrough in the next 12-24 hours.

[slats11]

Many posts ago somebody stated that their cell phone had received three texts welcoming them to a country that the aircraft they were in had transited at FL330

If this occurred it would have required a “handshake” signal exchange between the phone and mobile network operator.

I can’t help wondering if those coordinating the SAR effort have considered cross referencing the mobile phone numbers of all on board with every cellular network that flight MH370 could conceivably have over flown?

I wil guarantee you this has been checked very early on.

If we find this plane, more than likely it is due to some device that has been detected pinging away. Could be passenger mobile phones. Could be ACARS. Could be engine telemetry. These signals may have been received by various means other than the intended network.

Note that RR aren't saying there was no transmission. Just that they didn't receive any transmission. That seems to tie in with the WSJ clarification.


White House: Hunt for missing airliner may extend to Indian Ocean - The Washington Post

One senior administration official said the data showing the plane engines running hours after contact was lost came from the Aircraft Communications Addressing and Reporting System, or ACARS, a way that planes maintain contact with ground stations through radio or satellite signals. The official said Malaysian authorities shared the flight data with the administration.

Interestingly, this doesn't state in which direction the information was shared. Words can be chosen very carefully and used very specifically at times.

[mickjoebill]

Damage caused by a bomb, missile, un-contained engine failure or mid air collision does not necessarily mean a catastrophic in flight disintegration, with a significant amount of wreckage that would float.

So those who theorise since no wreckage has been found at sea level around the point of loss of contact that none of the above could have happened, should be more equivocal.:ok:

Nor do we know that any of the above events could have been reliably picked up by a surveillance satellite tuned to monitor "flashes", especially a brief flash from a small bomb that could be shadowed by the body of the fuselage.

The US say they have monitored some faint electrical/RF activity on the plane which they say was connected with engines running.
We do not know why contact with this signal was lost, the plane may either have crashed, landed and shut down or travelled out of reception range and so it could have continued on its way for a further hour or more.

They say they couldn't derive the heading of the plane from this signal so it may have turned again.

[Evey_Hammond]

Just found this link (https://www.mapbox.com/blog/flight-MH370-search-efforts-from-space/), unsure of how accurate it is but if there is truth to it then it's very interesting as it shows where satellites are being focused.

If you hover your mouse pointer over a coloured area it tells you the date the satellite was looking. It's interesting to see how many satellites have taken a look at Malacca (which has a runway) since MH370 disappeared.

http://i58.tinypic.com/35338yq.jpg