News and theories about the missing Malaysian plane

[Sailor Alan]

MH-370 Glider

Mr Efficiency, i hope i didn't claim to have designed the 777 (i helped with the wing tip), though i did help do the concept design for the Sonic Cruiser and 787. Perhaps thats whats wrong with the 787?

Imaginary number, without in any way trying to defend my creaky math, or opinions. I understand the Inmarsat satellites are geo-synchronous, i.e. stationary above a certain spot on the earths surface. Though traveling at very high speed, they have no relative motion compared to the earth receiving station, and hence no doppler shift. They probably have some ‘wobble’, all space craft do, and this certainly caused some signal interpretation issues.

I also know that timed ranging on a ‘working’ satellite transceiver in the plane is worse that useless, the handshake time is dependent on what other signals are being processed at the time. Perhaps ACARS was not using it at the time, but i'll bet ACARS was exchanging information with the satellite transceiver.

Regardless, the ACARS does not use the satellite when in VHF range, and though i do not know, i assume the satellite transceiver is turned off so the customer does not have to pay whilst it is not being used. ACARS would have used VHF until well out into the Gulf of Thailand.

As i mentioned in my diatribe, no one is obliged to release raw data, especially when it might contain militarily sensitive information, and it is also a useful vehicle to release information based on militarily sensitive information.

Knowing a little about Angus Houston, second hand from his ex service colleague, he is a very conservative and careful man, he made “Air Chief Marshal’ and head of the Australian armed forces, whilst my buddy went into industry. i doubt he would announce ‘pings’ when there were none.

I also still think the Mangos had something to do with it, and besides

https://au.news.yahoo.com/thewest/offbeat/a/23327395/one-in-ten-americans-think-aliens-stole-mh370/

 

[ancient kayaker]

"One in ten Americans think aliens were involved in the disappearance of the Malaysian Airlines flight MH370."

Of course, one in ten Americans has met aliens or is married to an alien, or maybe a mango. I read that someplace . . .

 

[Sailor Alan]

Mh-370

You were one of the 777 designers Alan ? I could not be trusted to design a paper plane to throw out the window, but that looks like schoolboy maths to me, the kind that gets marked with a cross !

Mr Efficiency, you are right, and i am wrong. In future i will get you to check my math before i publish it, and you are right to check the validity of your contributors.

I checked with my colleague at Boeing, “Engineer “X”, the aerodynamicist made famous by his development of the ‘Sonic Cruiser’ and incidentally the wing cross section of the 777. He and i still consult on Super Sonic Business Jets, and between us have several of the “Sonic Cruisers’ patents. He for aero, me for structure/manufacture. Most of the structure/manufacture developed for the Sonic Cruiser was used on the 787. For instance, http://www.google.com/patents/US7080805 for both, and http://www.google.com/patents/US7090167 for the Sonic Cruiser.

He roundly chastised me for my habit of doing such math in my head, and subsequently not showing my working. The ‘gliding’ speed of a trimmed 777 in sea water might be 8kts, and the Vne, or terminal velocity, might be 15-18kts in seawater. This limit will be affected by ‘cavitation’ in the rather severe hollow curves on the highly aft loaded wing cross sections, i.e. the rear half's of both upper and lower surfaces, though this depends on ‘trim’. The drag rises very rapidly with this effect. The drag coefficient is low at the best glide configuration, but lower still at Vne, i.e. a lower angle of attack. “Flat Plate’ frontal area is about 170sq/ft at its lowest trim drag, and empty weight about 160-175 tons with no gas left.

I discovered by checking the records at Boeing that i DID work on the 777, the horizontal empenage was the first major carbon composite structure, and i did quite a lot of work on its manufacturing processes. Sadly, i have no recollection of this at all.

After i finished work on the 787, lines ‘frozen’, spars, body, cab lines, frames, ribs and landing gear defined, engines, materials, manufacturing plan agreed, empenage, and control surfaces etc defined, i was assigned to other future projects.

http://www.google.com/patents/US8511608 Might possibly be used on the 797, as it allows the camber of the wing to be optimized for climb, top of climb and end of cruise, all different critical phases of a long flight, whilst also using the TE for control surfaces. The so called, “simplified trailing edge”.

http://www.google.com/patents/US20110056183 is the first practical, automatic, continuously variable cycle gas turbine, showing very significant improvements in specific fuel consumption over the climb, top of climb, and end of cruise phases. It will take some years to develop, i.e. not available for the 797, but will eventually make a dramatic improvement in fuel burn.

The Royal Aeronautical Society President awards just one ‘fellowship’ each year for “outstanding contributions to aerospace”, and i was the 2011 recipient.


For those of you still reading.

I spoke at length with a colleague, a civilian satellite communications expert working for the US Navy, who coincidentally uses the Inmarsat service. What he does is sensitive, but we could discuss some aspects of Inmarsat's service.

I thought the description of the ‘handshake’ in the released reports was a bit ‘odd’, the satellite does not care who it services, and would never usually send out an ‘invitation’ first. Certainly the FAA, at the other end of the connection has no such interest.

Apparently this system uses a “triangle’, or ‘3 way’, handshake. The airplane, or any other source of data, starts the dialogue with a signal to the satellite saying, ‘This is MH-370, are you ready to receive data’. The satellite checks its resources, and as appropriate replies, ‘yes’. This signal, though date stamped, is synchronized with satellite time. Now this signal is received by the airplane (date stamped in airplane time), and the data in a packet, is ‘burst’, preceded by the aircrafts satellite transmitters unique identification, and followed by some check information etc. As bandwidth is expensive on the satellite, this transmission is only an update, or refresh, from the last message, not all the data at all.

http://en.wikipedia.org/wiki/Aircraft_Communications_Addressing_and_Reporting_System

This works rather similarly to the AIS system for ships, but with a few critical differences. The ACARS system collects and transmits aircraft position, speed, heading, and height information to pass on to the FAA/Air traffic control. The lack of this in the middle of a flight should have raised immediate alarm bells, but the ACARS was switched off during the hand off between two different countries air traffic controls, so understandable, if not excusable.

It uses cheap VHF for parsing information when in range, but automatically changes to HF (earley versions) or expensive Satellite when out of VHF range.

RR started using this system to collect data from their FADEC, (Full Authority Digital Engine Controls), to report back to RR, with RR picking up the tab. Boeing uses the system to collect data on the status of the systems on board, and sometimes an airline will pay for their information. Airlines with a good maintenance program hardly need it, and those with a poor maintenance record, will rarely pay for it.

It is this second ‘pair’ of handshakes that is critical to the time/distance calculation. I’m given to understand the satellite has only 2MEG of RAM, 1-1.2MEG of which is taken up with operating system. Though the messages are quite small in terms of digital space, this is still a restricted volume. Hence, the delay between the initial request from the airplane and the satellites reply is a variable, unable to be tested. It was discovered that the satellites reply was always processed on the airplane in the same way when the ACARS was switched off, and with a constant time delay, by experiment. This led to the ‘discovery’ that a definite distance could be assumed from the satellite to a position line (curve) on the earths surface

 

[Mr Efficiency]

I would reckon "brain fade" or "mission fatigue" would be setting in in the search for this plane, I can only imagine the boredom of it all, and the suspicion they are all just wasting their time.

 

[ancient kayaker]

If I understand the concept the path plots are based on round-trip signal time (hence the constant-time parabolic curves) which would at least eliminate the need for a phase-locked reference or accurate time reference. It would seem to demand repeatable response times at both ends or accurate time logs in the messages, not necessarily the things that computer-based systems do best. However the odd few microseconds wouldn't be a big deal given the relatively low accuracy claimed. Including a GPS reference would have made such a difference . . .

 

[thudpucker]

I'm impressed with all the Knowledge and Research people on this forum.

I'm guessing we'll all be very surprised when we DO find the answer to 370's demise.

 

[RHP]

Mr E, I agree. Searching for this plane is on the same page as the search for bin Laden. If they found him, they can find the plane though.

 

[Sailor Alan]

If I understand the concept the path plots are based on round-trip signal time (hence the constant-time parabolic curves) which would at least eliminate the need for a phase-locked reference or accurate time reference.

Ancient Kayaker, you are correct. It is the second and third ‘handshakes, both time stamped by the satellite that were crucial to finding the constant time curve. Then the Doppler derived relative velocities had a ‘point’, or in this case ‘line’ of reference.

I was party to some of the original discussions between Boeing and the FAA about the use of ACARS for airplane data transport. We were already recording the data, and had a Radio link set up at some termini. The FAA’s valid argument was that their required data, call sign, course, height, speed, position, was necessary for collision avoidance, and had priority. It was also subject to ‘back up’ and redundancy rules. They didn't want another, non ‘urgent’ data stream clogging the system. Nor did they want gate/parked airplanes reporting position constantly when they were in a gate. Note, most airplanes have power on all the time they are in a gate, and often when parked as well, just like a ship.

Compare the displays of “flight aware” to “live ships and weather’ to see the different issues.

I wonder how the coast guard would enjoy having a ship transmit its oil temperature, engine RPM, and hatch status whilst sailing?

A similar issue arises with airborne entertainment systems. When a pilot makes an announcement, it is designed for emergency and aircraft safety, his announcement system needs to override all other systems, including ear buds etc, anything plugged into the airplane. This means all entertainment systems in the plane must legally, and practically, be connected into a triple redundant audio system, complying to all fire, and damage rules for primary flight equipment! A real problem when an entertainment company wants to add an entertainment system to an airplane.

Note; Boeing/United (they were once one company) did this to themselves by pilots tuning a spare radio into a ball game, and directing the output to the cabin so the PAX, all 6 of them, could listen in. This was in the days when radio, and airplanes, were quite new.

 

[ancient kayaker]

I agree planes need not send status data on the ground but their computers know they're on the ground so it can be turned off automatically. I would have thought that Boeing and others have something already planned to do this in their latest planes, it sounds like 95% of the requirements are already in place.

I can't agree with FAA arguments against implementing a 21st century satellite-based system to replace or supplement the half-century old recorder method. We're speaking of an automated report to a database that nobody needs to look at if the plane makes it to the airport so there should be no loss of pilot privacy and no extra work for anybody. The only possible objection I can see would be shortage of system capacity, but just adding the GPS location to existing reports would have made an incredible difference to the Malaysian plane situation.

I was under the impresssion that bulk carriers, tankers and cruise ships were already in continual communication with their operators and owners . . . ?

Like Thudpucker, I too would like to compliment and thank the experts like yourself who have provided the information missing from repetitive and over-simplified media reports.

 

[Mr Efficiency]

Even truck drivers are in constant communication with the company, in case they turn into roadhouse cowboys !

 

[ancient kayaker]

Even truck drivers are in constant communication with the company, in case they turn into roadhouse cowboys !

Much better chance of being found after a crash too! Come to think of it, if I were to crash my car it would phone for emergency services; I wonder if someone someplace knows every move I make in it . . .? Creepy thought!

 

[Sailor Alan]

Thank you, its been fun. The disappearance of flight MH-370 has exercised the aviation community like few before it. Changes will be made, and i hope they will be sensible.

Ancient Kayaker, according to some fictional TV Cop programs, someone can trace your car, and even you, through your cell phone, at all times. I suspect they trace digital watches, pacemakers, and corolla implants too, but that is another conspiracy.

Mr Efficiency, a colleague, who owned a trucking company, told me the tracking on his trucks was to tell which strip bar they had gone into, so he could extract them if/when necessary. I know a tanker full of petrol might be worth millions, so tracking them must be an issue. i am amazed no one has stolen one that i know of.

To be honest, commercial flight is safer than driving, and apparently safer than a ferry as well. The real cure is going to be better crew screening, not more automation. Even if someone on the ground had noticed its departure from the planed flight path, no airplane in Malaysia, or Indonesia's, military could have scrambled, and caught the plane with enough range left to do much except a single pass shoot down. No boat, helicopter, or anything else could have ‘met’ the aircraft at virtually any part of its assumed flight path in time, and picked up the passengers, even with the plane ditched successfully. In fact all Indonesia's helicopter force together could barely lift the passenger list, and Malaysia has far lower helicopter lift capacity.

I don't now remember why exactly, but i was one who favored having the pilot being able to turn the ACARS on and off. I like the pilot to ‘manage’ things, rather than have everything ‘automatic’, like switching from VHF to satellite link at range. We do have a landing gear “squat” switch, weight on the landing gear, though called a microswitch by virtually everybody, it is in fact a ‘hall effect’ device. There is also a parking brake ‘on’ switch too, though not every airline uses the brake, some like to use old fashioned ‘chocks’. Either could be used to ‘start’ data from the ACARS, but places like China, which does not accept current ACARS traffic, dumps the ACARS data to a very short range RF link triggered by the planes presence in the gate.

When we designed the ‘dream lifter’, the chief pilot and i managed to convince the team that we didn't need cockpit indicator lights on the rear swing door/tail, mechanical tell tales would be best. The co-pilot checks such things with a flashlight before each flight, and having a warning light coming on during flight was not only usually a false indication, the crew could do nothing about it anyway.

Were we to propose a sea-born ACARS, can you imagine finding a reliable “hatch closed’ indication device that would withstand the rigors of container port loading and unloading, salt air, and be more reliable than an officers eyes.

Finding this wreckage will be a long hard slog, perhaps never successful. Bin Larden was apparently found by a female operatives dogged, some say obsessive, follow up, especially of possible couriers. A ‘cheap’ one or two people effort, so nearly invisible to an administration, but sooo! successful. In the case of MH-370, no such indicators exist that i know off, though floating wreckage may eventually turn up, perhaps after bits of the plane decay, but that will be a while too. i don't know if seat cushions etc retain their ‘buoyancy’ under 6,000+ psi. I doubt we tested them.

 

[RHP]

I'm currently in Bangladesh where it's common knowledge there were 122 Chinese workers enroute home from an Iranian nuclear facility and they were 'taken out'. There is no shortage of imagination here.

 

[Mr Efficiency]

I am sure there is a lot to the story we have yet to hear, and likely never will, too many sensitivities involved.

 

[ImaginaryNumber]

Malaysia to Release Satellite Data on Missing Jet MH370 | NBCNEWS

Malaysia has bowed to pressure from the from the families of passengers on missing flight MH370 and will publicly release the Inmarsat satellite data used to narrow down the search area...

In an open letter sent earlier this month to the leaders of Malaysia, China and Australia, the relatives questioned how authorities could be certain the Boeing 777 had crashed into the Indian Ocean after vanishing without a trace on March 8. No wreckage has been found...

It did not say when the data will be released...