Sanity Check - 3/26/2014 - 03:40Z
Re-posting in the new thread since I ended up at the end of the last one.
There is (will be) a link to this post in my profile under "homepage".
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Formating notes.
New/changed lines will have this background color. All changes are relative to the previous Sanity Check. | Previous Sanity Check here. NOTE: this link will place the entry at the top of the screen, you will have to expand it.Previous Sanity Check. (by rcair1 Mar 21 2014 in Civil Aviation) | Minor wording/grammar/spelling changes are NOT highlighted. |
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Introductory comments:
This is the first updated Sanity Check for some days. This simply because there has been no news till the recent announcements from Malaysia and Inmarsat. I was loathe to spend too much time just addressing conspiracy theories for which we have no data.
To be clear - while I believe we know the plane has gone down in the South India Ocean, we have no better idea of why it flew there than we did on March 8.
Therefore the speculation, conspiracy theories, idle chatter, continues and will.
As before, this sanity check will focus on what we know more than what we think. |
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Changes in this edition.
• | Discussion and refinement of Inmarsat data. | • | Various sections simplified and clarified. | • | Doppler tutorial added. | • | I've shortened several sections- I have not highlighted those changes. The heading will say something like "Shortened". I did not hightlight them because I'm limited in formating. |
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First, I'm going to start with a restatement of what we know - right up front.
• | The aircraft departed KUL normally then secondary radar, voice and ACARS Contact was lost. | • | The aircraft turned west, then north west and primary radar contact was lost. | • | The aircraft continued to fly, or operate, for approximately 7 hrs. | • | We have not found the aircraft or wreckage and have not received any ELT transmissions. | • | The aircraft is lost (in the sense of crashed) with all souls on board. May they Rest in Peace. | • | The aircraft flew south into a remote part of the Indian Ocean. | • | Probable location of aircraft at last 'ping' place it 4-5 hours from major land with 30-45 minutes of fuel. | • | A final "partial ping" was received 8 minutes after the last one. Unknown reason - investigation underway (potential indication of power failure/flame-out). |
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Yes - I know:
• | There are those in this forum who will disagree that we "know" those last 3 items as we have not found debris or wreckage. | • | When (if) we find that wreckage, some of those will continue to deny the plane few there - they will postulate China or Malaysia or the US or "somebody" place the wreckage there. | • | I believe the data to be credible and factual if not 'proven'. It is beyond reasonable doubt. | • | I would be happy to be proven wrong - that the plane landed somewhere safely - and will gladly admit it. |
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First a synopsis
• | The ship took off normally and headed on course to Beijing | • | The last ACARS transmission was 01:07 local. | • | Reports that ACARS indicated new way-points were programed into the FMS before have been denied or have credible non-threatening explanations (see Way-points) | • | The last comms were "All right, good night" transmitted to Malaysia at hand-off to Vietnam control. Vietnam was not contacted. It has been reported it was the First Officer's voice. | • | NOTE: This sign-off is not atypical or unusual. If anything it tends to argue for normalcy (though deception cannot be excluded). | • | The transponder stopped transmitting at 1:21 - loss of secondary radar. | • | The discussion of climbs and descents seems to have changed. This matter is still unclear. | • | Inmarsat data is consistent with 30K cruise - no indication of fluctuating altitudes during majority of flight. | • | There are subsequent primary radar returns west over Malacca Strait and then north west. Since it is primarily radar - a reflection - it does NOT identify the a/c, however it has been correlated with SATCOM pings so confidence is high that the returns are from MH370 | • | SATCOM system pings continued for 7+ (last ping at 08:11 local) hrs after LOS (loss of signal) | • | Using newly developed analysis, the SATCOM data has been used to exclude the so called 'north' corridor. (See Advanced analysis of SATCOM Pings). | • | This new analysis has allowed us to dramatically reduce the search area. It has also, unfortunately, placed the aircraft in a location where safe landing at fuel exhaustion is not possible. | • | A last "partial ping" was received 8 minutes after the 8:11 ping. The meaning of this is unknown, but speculation is it may have been an indication of fuel starvation and shutdown. | • | Searching continues for debris in the South Indian Ocean, but the location, weather and conditions are poor |
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Time-line
• | 1:07 am - Last ACARS transmission. | • | 1:19 am - Last verbal communication "All right, good night" from the plane; believed to be the co-pilot | • | 1:21 am - Transponder stopped transmitting (turned off or failed) | • | 1:30 am - Civilian (primary) radar lost contact | • | 1:37 am - Expected ACARS transmission; not received | • | 2:15 am - Last military primary radar contact | • | 8:11 am - Last (hourly) satellite handshake | • | 8:19 am (approx) A 'partial ping' was received - potentially and indication of power fluctuations at fuel starvation. |
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ACARS
• | ACARS is an automated aircraft communication system that transmits a/c information, including navigation, operations, maintenance, etc to ATC and maintenance facilities. | • | ACARS is NOT a flight system - it is not needed for safe flight. | • | ACARS is a subscription service and costs money. All indications are the MH370 was subscribed only to engine health monitoring and data from that is sent to Rolls Royce. | • | This last fact (only EHM) is somewhat questions because of 3/18 reports of new way-points being programmed. This would require ADS-C | • | ACARS communicates via VHF, HF or SATCOM. The communications channel depends on availability and is independent of the ACARS. | • | ACARS can be instructed not to use SATCOM, HF or VHF from the Cockpit. This would effectively stop ACARS from sending data. Access to the EE bay is not required. | • | The last ACARS transmission was at 1:07. The next was expected at 1:37 and was not received: This means ACARS communication was disabled between those times. This could be action by the flight-deck crew or system failure. |
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ACARS data from MH370
• | The ACARS system sent 2 engine health reports to Rolls Royce, both prior to the LOS event. | • | The Rolls Royce page indicates that a 'snapshot' of engine data would be sent at: takeoff, climb, cruise and landing. We know 2 ACARS Engine Health reports were received, consistent with the 1st two. | • | The last engine health report was received at 1:07am. The next was expected at 1:37 am and was not received. This indicates that the transmission of ACARS data was disabled between 1:07 and 1:37, but not when during that period. | • | The Engine Health report received prior to LOS had 'interesting' altitude data/fluctuations including 40K drop in a minute. That data is suspect. | • | There seems to be some indication that ADS-C data with changed way-point information was included in the last ACARS report. This has not been confirmed and has, in fact, been denied. | • | A recent report stated that is was "normal" for MH pilots to turn off ACARS for flights into China. This has not been verified and seems inconsistent with SATCOM coverage. |
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ADS-C Tutorial.
• | ADS-C stands for Aircraft Dependent Surveillance - Contract. | • | The "Dependent" is because it "depends" on the aircraft taking action - as opposed to "independent" like radar.. | • | Contract means there must be a "contract" or "agreement" set up by the controllers an/or crew to send information. | • | ADS-C is not required to be used. | • | ADS-C can be programed to report periodically, on demand, on event. It can be initiated by the crew in an emergency. | • | There have been reports - now denied - that the ship turned before LOS, or that that new way-points were programmed before LOS. | • | The only way this (later) item would be know is if the ACARS Predicted Route Group was sent. That includes ETA, altitude, lat/long at next way-point and next+1 way-point. | • | ADS-C is transmitted via ACARS which can use SATCOM, VHF or HF. | • | ADS-C does not transmit via transponder (thanks for that correction) | • | A good tutorial on ADS-C is available at http://prezi.com/pcuvxhcklsda/ads-c-overview/ |
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Way-point Entry Data.
• | I have deleted this section which dealt with reports of turns before LOS and insertion of new way-points before LOS as these reports continue to be postulated and denied. | • | I will add that information if it becomes factual. |
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Way-point Tracks.
• | A series of way-points reported that match the primary radar tracks in/near Malacca Strait. | • | These way-points line up with the direction indicated by the primary radar returns and Inmarsat data to the north. | • | While many believe the aircraft was under control - we cannot conclude if these way-point were used, or just coincidentally along the path. | • | A 777 can be programed to follow a series of way-point automatically - this is normal operating procedure and a 777 pilot would need no extra practice/training to do it. (Relevant to pilot flight simulator ownership) |
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SATCOM
• | SATCOM is a communications channel - Satellite Communications. It is a radio system that uses satellites to communicate various information. | • | SATCOM is not ACARS - it is one of the channels ACARS can use. | • | The Inmarsat Senior VP likened the Inmarsat box on MH370 to a 'handset' and the Satellites to the network. ACARS, Texting, etc are all "applications" that run on the 'handset' | • | The system pings the aircraft roughly hourly. | • | The SATCOM system on MH370 is a "Classic Aero" set and connects to Inmarsat 3 satellites. In the area covered, the only satellite with coverage is IOR. (Source Inmarsat) | • | The SATCOM system sends (or responds to) periodic 'pings' to/from the satellites (hourly). These 'pings' are a network communication that says "I am here." | • | SATCOM pings are not communicating a/c status, they are part of the communications channel. They are akin to registration pings on a cell system. | • | SATCOM pings provide no aircraft location, heading, speed or altitude information. | • | NOTE: There are versions of Inmarsat solutions that provide more location information than we have for MH370 (Inmarsat-4). | • | However, this a/c did not use this technology and the pings are handled over the low bandwidth, non-directional global antenna. | • | Claiming that it did (have newer versions or use directional antennas) is yet another unsubstantiated theory that would require massive conspiracy at Inmarsat. Why? I don't buy it | • | I have deleted the rest of this section in light of new Inmarsat analysis (see below) |
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Advanced analysis of SATCOM Pings
• | Over the past 24-48 hours we have learned that Inmarsat has developed new analysis techniques to improve their estimation of MH370's likely path. Inmarsat should be applauded for this work. | • | As I understand from information presented by Inmarsat, the analysis included: | - | A component of Time of Flight analysis - how long does it take the signal travel from the satellite to the a/c and back. | - | A component of frequency shift analysis (based on the well known Doppler effect - see below). | - | Inclusion of variation in position, with time, of the IOR satellite (wobble). | - | Specific correlation with other a/c (777 I believe) using the same type of equipment in the same relative routing. | - | Specific information about this a/c from previous flights and ground communications to understand the signature of this specific installation. | - | Assumptions for various airspeed and altitude (somewhat driven by a/c performance models.) | • | As a result of this analysis, Inmarsat has been able to eliminate the "north" corridor previously identified. | • | This graph shows how the correlation between north corridor and the MH370 data is poor, south corridor data and MH370 data is good. | • | Combining that information with other data - we can conclude with high confidence that MH370 flew south into the Indian Ocean where it crashed due to fuel starvation. | • | NOTE: I've simplified this dramatically | • | Other figures of interest. | | |
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Doppler Effect - a simple tutorial.
• | The Doppler effect (named after Austrian physicist Christian Doppler) is something we have probably all experienced. | • | The most common case we may be familiar with is how a train whistle will decrease in pitch as the train goes by. | • | It works like this (sound wave based). | - | The train whistle we hear is the result of pressure waves in the air causing motion of our ear drums. | - | Let's assume that the horn frequency is 200 Hz, the speed of sound is 340m/s and the train is coming at us at 100km/hr (27.7m/s). | - | This effectively adds to the speed of sound and decreases the 'effective wavelength' because the source is moving towards us. | - | The sound we will hear is about 220Hz - it is higher than the train tone. | - | When the train passes it is now moving at 27.7 m/s away from us and the tone drops to about 180Hz. | - | This is a big change and we can clearly hear it. | | | • | In the case of the Inmarsat satellites, the "ping" is carried on a radio wave operating at, I believe, about 1.6 GHz so the wavelength (use the speed of light, not speed of sound) is about 18.737028625cm | • | There is a reason I included so many digits | • | Ignoring satellite motion, if the aircraft was moving directly at the satellite at 450 knots (231.5m/s) - the sensed wavelength is 18.73701415625cm | • | Ignoring satellite motion, if the aircraft was moving directly way from the satellite at 450 knots (-231.5m/s) - the sensed wavelength is 18.73704309375cm | • | Now - if I've done my maths correctly (and I would encourage checking here), the percentage change is 0.00015% - on the order of 1 part per million. | • | And of course, this is the best case - the a/c moving directly toward (including climbing) the satellite and directly away (descending). | • | In the case of MH370 - the Doppler effect was much smaller because the aircraft is not climbing/descending and is moving at an angle to the satellite. | • | In addition, this is being measured by a device that is designed not to measure it. | • | Satellite motion will add/subtract from this as well and was key to the analysis | • | It should be clear from this that based on this you cannot take a simple single measurement from a single ping and calculate meaningful data. | • | What Inmarsat did was compare (correlate) data from MH370 with similar data from a/c traveling on similar routes. That correlation matches will with a southern route, not well with a northern route. | • | Authors note: I hesitated to provide this analysis because 1) it is pretty deep and 2) it will open the door for those who say "No way they can calculate that." | • | However, I believe it is better to discuss it openly than to 'hide it from the uneducated masses." | • | Face it - conspiracy theorists will dismiss anything. Those interested in learning and perhaps questioning logically (thus providing better insights/options) will do so. That may lead to better understanding." |
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Fire Theory (Was Cargo and Lithium Batteries).
• | I'm leaving this here because it continues to be discussed. However, until (and if) we get further data - this is just one of many speculations.
I would point out that most authorities are pointing at human action versus mechanical failure (of any sort). | • | One hypothesis that has been presented is that a fire broke out incapacitated the crew/passengers or caused hypoxia that did so. | • | The hypothesis is: | • | A fire broke out causing the crew to disable multiple systems (or disabled them itself) | • | The crew was successful in containing/extinguishing the fire - but then was disable due to smoke and/or hypoxia. | • | The a/c, either on autopilot or uncontrolled by stable due to advance FBW systems, remained in stable flight till fuel exhaustion. | • | The turns exhibited could have been a combination of programmed and random course changes. |
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Hypoxia and Pressurization
• | There has been lots of speculation about loss of pressurization in the aircraft and what that would do to passengers and crew. | • | IMPORTANT NOTE: all of this applies to cabin pressure - not the pressure outside.Just climbing to 45K would not exposed the passengers to that altitude - the aircraft would have to be depressurized. | • | In the case of loss of cabin pressure - O2 mask would deploy automatically. | • | Cockpit alarms would sound - comparison to Helios is not valid (777 and 737 are very different). | • | The 777 can be modified for operation at very high altitude airports w/o alarm - however, that just raises the alert altitude, it does not disable it. Further - there is no evidence this 777 has been so modified. | • | The pilots cannot disable this above 13,500 feet - they can release the masks. | • | Passengers masks would last 12-20 minutes. Portable crew (FA) bottles ~30minutes. Cockpit crew longer. | • | Time of useful consciousness (not to loss of consciousness) will range from 1-3 minutes at 30K to 9-15 seconds at 43K. (http://en.wikipedia.org/wiki/Time_of_useful_consciousness) | • | above 40,000 ft cabin altitude - positive pressure oxygen is required - passenger masks do not do this and would not be effective. | • | Because of this the a/c must be certified able to descend and pilots demonstrate an emergency descent to ~10,000 ft in 2 minutes. | • | The actual regulation is that passengers cannot be exposed to a cabin altitude of more than 25K for more than 2 minutes, or more than 40K for any time. (A380 got an exception to this rule.) |
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Cabin depressurizing by Pilots (shortened)
• | Pilots can depressurize the a/c by turning pressurization to manual, turning off bleed air and opening outflow valves. (I have no information on how quickly this would lower cabin pressure. | • | This would not disable either alarms or auto-deploy of passenger oxygen masks. | • | Let's investigate the sequence required. | • | 1) Pilots (or whomever is in control) switches to manual pressurization, turns off bleed, opens outflow valves. | • | 2) Cabin altitude climbs above 13,500 and passenger masks deploy - there is no way to prevent that. At that point passengers and cabin crew know. | • | 3) Presuming the pilots do not descend - passengers O2 will last 12-20 minutes. After that, depending on the cabin altitude they will loose effective consciousness (not loose consciousness, but effective consciousness). | • | 4) Cabin crew O2 will run out. | • | 5) During this time, the flight crew O2 will operate (and last longer) | • | 6) At some point - depending on cabin altitude - those not on O2 will become disabled or die. | • | NOTE: Above 40K cabin altitude passenger masks are ineffective - positive pressure O2 is required. | • | NOTE: The a/c itself is not impacted by depressurizing. |
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CRV/FDR Data
• | The CVR (cockpit voice recorder) and FDR (flight data recorder) do not transmit data in flight. | • | They do emit sonic pings if immersed. These will last a minimum of 30 days. We can expect sonar is being used to listen for them. | • | The pinger operates at 37.5KHz 106.5dp re 1μPa. (thanks k83713) | • | Maximum depth of beacon detection in Normal Conditions: 1-2km | • | Maximum depth of beacon detection in Good Conditions: 4-5km | • | Localising a pinger from the surface in shallow water is relatively easy, as described above. In deep water, the detection equipment should be installed on a self-propelled underwater vehicle, presupposing that the position is already known to within the maximum 2-3km detection range. | • | The CVR reportedly is a 120 minute CVR so it would contain only the last 120 minutes of flight (presuming it did not fail or was turned off prior to that). | • | I don't have data form the recording time of the FDR, but it is typically much longer. |
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ELT
• | The ELT, or emergency locater transmitter is mounted in the rear of the aircraft - difficult to access in flight. | • | The ELT is battery powered - independent built in power source. It is this source that is suspect in causing the 787 fire at Heathrow. | • | The ELT will be trigged by G forces in a crash. It will not operate under water. | • | The ELT can be triggered from the cockpit - it is a hardwired switch not dependent on computer systems. | • | The ELT transmits on the guard frequency (VHF) and on 406MHz to satellites. If it had been triggered (above water), satellites would have heard it and been able to locate the a/c. | • | Clarification: there are additional manual ELT's in the cabin that can be activated by crew members, and on slide rafts, but they do not include g-force sensing. |
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Primary versus Secondary Radar (brief tutorial)
• | Primary radar is based on the original military usage. It sends out a strong (KW to MW) signal and looks for a reflection from something. | • | Primary radar provides distance and location. Comparing returns speed can be determined. Strength of return can indicate size. | • | Stealth a/c and ships are designed to absorb or miss-direct the reflection so primary radar cannot see them. | • | Primary radar does not depend on the transponder, so turning off a transponder will not make an a/c disappear from primary. | • | Primary radar is less prevalent than secondary - and more typically military tho ATC's do use it. | • | Secondary Radar is really not Radar in the defined sense. It is directional communication. | • | In secondary radar a directional signal is sent out (much less powerful than primary). Any a/c with a transponder that receives it will respond (the transponder responds) with information about the aircraft. | • | Combined with the direction of the outgoing beam, the time of flight information and returned information, the a/c location and identity (and other info depending on the mode) is returned. | • | Secondary radar is the primary method used by ATC. | • | If the transponder fails or is turned off - secondary radar will not see the a/c. | • | In the case of MH370 | • | The transponder was turned off - so the a/c disappeared from secondary (ATC) radar. | • | A target was tracked west, then northwest using primary radar. That target was correlated with SATCOM pings help determine it was MH370. |
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Airworthiness Directive
• | The airworthiness directive about corrosion near the SATCOM antenna does not apply to this ship. | • | The ship DOES have SATCOM - but uses a different antenna |
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Aircraft Type and Fuel State
• | The aircraft was a Boeing 777-200ER. MTOW 656,000 lbs, 301 3 class passengers (standard Boeing Config - does not reflect MH specific config.) | • | The aircraft could land in 6000 ft, or much less at high risk. As little as 3000ft has been stated, but it could not take off from there. | • | The aircraft would need a hard surface to land - this is heavier that has been done on steel matts. | • | It is reported the aircraft 45 to 60 minutes extra fuel. This would amount to about 7-7.5 hrs of fuel. This is a normal amount for this route. | • | The aircraft should have been able to fly about 30 minutes after the last SATCOM ping at 8:11. | • | The figure at this link show max range for the 777-200ER. NOTE: MH370 was not fueled for this range. http://www.boeing.com/assets/pdf/com.../777_range_singapore.pdf |
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Can a 777 fly 'by itself' for 7+ hours.
• | There has been much debate on if the 777 could continue to fly without human intervention for 7+ hours. | • | Fundamentallywe know the aircraft did fly on - so any theory must support a potential for the aircraft to continue in flight. | • | Satcom data has eliminated the "stationary on the ground" theory | • | Without information on the conditions on the aircraft - we cannot make a determination of what the a/c could or could not do. | • | We can make some educated statements: | • | If under human control - obviously it could fly this long. | • | On full autopilot it could fly on - however, that would assume a course was programmed in. If a 777 is programed to a way-point and it reaches that point - it will continue on the last heading. | • | If in heading and speed hold mode - it could fly to fuel fuel exhaustion. | • | In a 777, unlike and Airbus a/c, upon flame out the 777 will pitch down to maintain speed. An airbus will pitch up to attempt to maintain altitude till alpha prots cause it to decent at just above stall, nose up. No argument about which is better please. It is irrelevant - both will descend. | • | In summary - there are multiple scenarios where the a/c would have continued in flight till fuel exhaustion. We have no data or basis to include or exclude any of them. |
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Search Areas
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Mobile phones
• | We continue to have lots of discussion on "mobile phones" - can the connect in flight, etc. | • | We don't have any reports or evidence of that any passenger or crew mobile phone has registered with any network. | • | Until we have that data or reports - I believe the mobile phone discussions are not getting us anywhere. | • | UPDATE: This subject continues to be discussed. But, we have had no reports of cell phones registering with towers - we are in a loop here. |
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Most Common Theories. Note - all have problems!
• | Successful hijacking either with crew complicity or not, followed by controlled flight somewhere. Argument against: most believe we would have found/tracked the aircraft or heard something from the hijackers. Also, actions by passengers. | • | Unsuccessful hijacking either with crew complicity or not, followed by automatic flight to fuel exhaustion. Argument against: Likely the passengers would know and some action would be taken. | • | Pilot homicide/suicide followed by controlled or automatic flight till fuel exhaustion. Arguments against: No evidence of motive. Why fly to remote area rather than immediate crash. May require hypoxia to disable cabin crew/passengers. | • | Mechanical failure that disabled all comms, disabled crew/passengers but left a/c flying in an automatic mode: Theory not in favor with investigators. |
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Less Common Theories and Conspiracy Theories (simplified)
• | Other theories that seem less likely or fully improbable - however most are versions of the above. | • | A fire broke out that incapacitated passengers and crew - but allowed to aircraft to fly on it's own till starvation. This is a form of the Mechanical failure theory based on fire. | • | The aircraft "shadowed" either a KLM or SIA aircraft to hide from radar then turned off the track and landed. | • | Freescale engineers have been hijacked for sensitive US data. | • | There was something in the Cargo worth stealing - which is why it was not screened. | • | The plane was full of undeclared gold.Gold is very heavy - what would you declare the cargo as? | • | The US hijacked the 777 using on board FBW technology to fly it like a drone to Diego Garcia (this one wins the insanity case). | • | There has been a claim by counter terrorist expert that this could be a "cyber hijack" - a malicious attack of a FBW a/c by somebody in the back with a smart phone. |
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Crew Related Theories
• | The crew and passengers are a focus of investigation. Particularly the crew, because of the difficulty of managing an external cockpit intrusion. | • | The pilot has received a lot of attention because: 1) He supports opposition politics, 2) He has a mongo flight simulator, 3) There are rumors of family problems (debunked???). |
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Dismissed or Confirmed not True
• | Chinese Satellite Debris - nothing found in area. | • | Oil worker report - nothing found in area. | • | Greek shipping debris - nothing found/not related. | • | Raft with "Boarding" found - not related | • | Original 'debris' reports (March 8/9) not related/nothing found. | • | Maldives low flying a/c - not related. | • | Cell phones ringing - artifact of the cellular system. | • | Aliens. |
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IN summary what we know is.
• | The aircraft departed KUL normally then secondary radar, voice and ACARS Contact was lost. | • | The aircraft turned west, then north west and primary radar contact was lost. | • | The aircraft continued to fly, or operate, for approximately 7 hrs. | • | We have not found the aircraft or wreckage and have not received any ELT transmissions. | • | The aircraft is lost (in the sense of crashed) with all souls on board. May they Rest in Peace. | • | The aircraft flew south into a remote part of the Indian Ocean. | • | Probable location of aircraft at last 'ping' place it 4-5 hours from major land with 30-45 minutes of fuel. |
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That is all.
Respectfully Submitted - rcair1
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