All you need to know about MH370: facts, timelines, systems, findings, theories

Let’s try to summarize all what is known to date about the mysterious MH370 flight.

This post contains a complete review of all the Malaysia Airlines 370 story, with new and revised details, update data and findings.


1) MH370 took off normally and headed on course to Beijing as planned. Just before Loss of Contact (LOS) the aircraft turned right to HDG040°. At the time the transponder stopped transmitting, based on ADS-B data, the aircraft was flying at FL350.

2) MH370 was following the usual route to Beijing.

3) Based on reports, the weather in the area was good.

4) The last ACARS transmission was 01:07AM local.

5) Reports surfaced yesterday that the aircraft either: turned westwards before the last voice transmission – or- entered two new waypoints in the FMS (see ADS-C section).

6) The last radio comms were “All right, good night” transmitted to Malaysia Air Traffic Control at hand-off to Vietnam control. Vietnam was not contacted. It has been reported it was the First Officer’s voice. Although it is not a standard phraseology reply, the “good night”, “ciao”, “au revoir” etc way to greet ATC at hand-off is quite common and, per se, it does not constitute any evidence of something wrong in the cockpit.

7) The transponder stopped transmitting at 1:21AM LT.

8) There are reports of a climb to 45,000 ft, uneven descent and some changes in altitude. However, this changes are based on primary radar, and altitude data is uncertain at that distance from radar.

9) According to the Malaysian authorities, there were subsequent primary radar returns to the west of the Malaysian peninsula, over the Strait of Malacca and then north west. This is assumed to be a real return from MH370 even if based on primary radar echo.

10) SATCOM (see below for details) satellite system pings continued for 7+ (last ping at 08:11 local) hrs after LOS (loss of signal)

11) SATCOM pings do not locate the aircraft but based on correlation to signal strength latency, satellite height, it is possible to draw arcs (of a circumference centered on the satellite with radius = distance from the satellite) where the last ping may have been located. The arcs identify a series of points at the same distance from the satellite and are located along two directions, the first is north from Andaman Sea to Turkmenistan; whereas the second is south, over the Indian Ocean from southwest Malaysia to southwest of Australia. The last primary radar reply came from a point that is coherent with the northern arc.

12) The last SATCOM ping replied by the aircraft reportedly was at 8:11 am Malaysian time. At that time it would be dark on the north arc and light over the south arc.

13) SATCOM pings are hourly – so the 8:11 ping could be up to 1 hour before the aircraft stopped ‘pinging’: the aircraft onboard systems could reply to ping (for more details read below) even if the aircraft had landed, while it is difficult to believe they could reply after crashing.

14) A pilot of another plane in the air when the aircraft failed to contact Vietnamese control, heard a weird “mumble” or noise seemingly coming from a stuck microphone from MH370 but there is no way to confirm this.

15) According to the Malaysian PM, the way the aircraft has flown since LOS make investigators believe it was a deliberate action.

16) Reports of sightings in Maldives, landing in China etc have been debunked. Thailand has admitted to have possibly tracked the plane on Mar. 7, after LOS,  but only gave this information some 10 days after the disappearance.

17) All the previous alleged sightings of the aircraft debris (Chinese satellite images, Greek ship reports, Tomnod crowdsourcing initiative etc) did not find anything that could be related to the missing plane.

18) Based on satellite imagery collected on Mar. 16, search and rescue aircraft, including a P-8A are investigating possible debris located 2,300 km to the southwest of Perth, Australia.

MH370 update 2


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


ACARS is the acronym for Aircraft Communications Addressing and Reporting System. It’s an automated communication system used by commercial planes to transmit and receive messages from ground facilities (airline, maintenance department, aircraft or system manufacturer, etc). Therefore, along with the general information about the flight (callsign, speed, altitude, position, etc), these messages may contain what we can consider systems health checks.

ACARS is a service: airlines have to pay for it. According to the information available to date, it looks like Malaysia Airlines subscribed only to engine health monitoring that enabled MH370 to send data to Rolls Royce.

The ACARS system aboard MH370 last trasmission was at 01:07 LT.

However, it has emerged on Mar. 18, that last trasmission included new way-points that were possibly entered before the loss of contact, using the FMS. This would require ADS-C (see below).

ACARS rely on VHF frequencies (indeed, you can track planes and decode messages with a simple radio receiver tuned on the proper ACARS frequencies and a software running on your computer) or SATCOM (SATellite COMmunication).

Although this is still debated, according to several pilots the ACARS transmissions can be switched off by the pilot from inside the cockpit, by disabling the use of VHF and SATCOM channels. This means that the system is not completely switched off, but it can’t transmit to the receiving stations.


SATCOM is a radio system that uses a constellation of satellites used to trasmit voice, data or both. As said, ACARS can make use of SATCOM to transmit its data to ground stations. Dealing with ACARS, the SATCOM system used by MH370 was linked to the INMARSAT network.

Inmarsat is a British satellite telecommunications company, which offers global, mobile services through a constellation of three geostationary satellites.

The system relies on “pings”.


A Ping is a quite common term for IT Networking. It refers to a utility used to test the reachability of a host on an IP network and measure the round-trip time (RTT) of the packets even if it is more frequently associated to the data messages themselves, or “pings”.

Similarly to what happens on a Local Area Network, satellites send pings (once a hour) to their receiving peers that respond to it thus signaling their network presence. Hence, these pings are no more than simple probes used to check the reachability of SATCOM systems aboard the planes.

Based on details recently disclosed, the last response to a satellite ping, was sent by the SATCOM aboard MH370 at 08.11AM Malaysia time, some 7 hours past the loss of contact with the Boeing 777.

From the analysis of the time between request and response it is possible to work out the distance of the plane which is a circumference of certain radius from the satellite based on which, two possible arcs containing all the final points were drawn by the investigators.

Search MH370 WaPo


ADS-C stands for Aircraft Dependent Surveillance – Contract. It is a dependent system (depending on the aircraft using it) that sends information based on a “contract” agreed by the controllers and crew. Information can include altitudes, estimates, coordinate for next waypoints and subsequent waypoint.

ADS-C can be programed to report periodically, on demand, on event. It can be initiated by the crew in an emergency.

Based on the revelations that the waypoint past the point of LOS were known to the authorities, it can be assumed that either, ACARS report at 1:07 included the “Predicted Route Group” or that they just meant that the path followed by MH370 was seemingly flown automatically, as if the plane’s primary radar tracks match with waypoints on a published airway.

ADS-C is transmitted via ACARS (which, as said, can use SATCOM, VHF or HF channels).


ELT – Emergency Locator Transmitter. It is a battery powered system that transmits on the guard frequency (121.5 MHz on VHF and on 406MHz to satellites. If can’t transmit from under water.

Mobile Phones

Although this topic is quite debated, reports say that no cell phone belonging to people on board registered with network towers. This may depend on the altitude the aircraft, the route (above the sea), or the fact that they were either seized to passengers or these were unconscious hence unable to switch them on.

Pressurization / Hypoxia

Cabin pressurization can be regulated by the pilots. This means that cabin could be depressurized to the airplane’s current altitude using manual pressurization.

In the event of the reported climb to 45,000 feet (determined based on primary radar – hence, to be confirmed), masks would deploy providing passengers Oxygen for 12 to 20 minutes (usually, just the time required to descend to below 10,000 feet). After that, passengers would lose consciousness and, at some point, they would die. Pilots O2 lasts more.

The same effect would be achieved at much lower altitudes: the main difference would be that death would arrive earlier at higher altitude (45K above the aircraft max altitude).


There are so many active theories that is almost impossible to list them all. We’ll try to list the most significant ones. Please consider that a “composite theory” made by hijacking and subsequent failure is possible as well. We will not consider such mixed theories.

Anyway, the main question here is: did the aircraft suffer an in-flight emergency or not? Although this author still believes that the aircraft was diverted from its initial planned route by a pre-planned action, the possibility it experienced a catastrophic emergency can’t be completely ruled out. Still, it seems to me a bit far fetched that the B777 suffered a failure that disabled the transponder, radio, ACARS, etc. but (possibly) left the plane capable to fly (on autopilot?) for 7 hours.


The aircraft is hijacked. Then it crashes after 7 hours for fuel starvation.

Based on the current information, this is a likely scenario (at least for the first part of the flight – when the transponder was switched off). Hijacking may have been attempted by one of the pilots, then fighting occurred, one or both might be wounded and unable to complete the diversion to another country, the asylum request as happened for Ethiopian flight last month, or his terrorist attack.

It looks like the theory that passengers with stolen passports could be involved in a hijacking attempt was debunked.


Fire in the cockpit or cabin.

As mentioned before, fire in the cockpit that would selectively disable some aircraft communication systems but didn’t prevent the aircraft from flying is unlikely.

Progressive series of failures

First failure forces pilots to turn then other issues arise until the aircrew and passengers succumb and the aircraft crashes for fuel starvation.

As above, fire or smoke in the cockpit that would either selectively disable some aircraft communication systems or make aircrew unable to react, without affecting the aircraft’s capability to fly (most probably under FMS inputs) is unlikely.

Attempted landing at divert field

System failure or failure aboard. The incapacitated pilot points the aircraft towards the coast to land at Langawi but then fly until fuel starvation and crashes.

Unlikely, for the same reasons mentioned above plus the fact that a pilot trying to land at nearest airport would not switch off transponder.

Aircraft stolen

The aircraft was hijacked and moved in some rogue state to be used for future terrorist attacks.

Aircraft must be hijacked, secretly flown to a secret location escaping radar detection in the shadow of a larger plane, then landed on an unprepared, hidden landing field. Passengers killed or moved elsewhere. Quite unlikely, considered the maneuver to join another aircraft enroute, but not impossible.

Subscenario: passengers kidnapped for ransom: unlikely, because no claim nor ransom request after all these days.

Subscenario 2: passengers kidnapped for their skill and know how.

Subscenario 3: cargo stolen. Cargo manifest doesn’t list anything special and would you organize such a risky operation just to steal the plane’s cargo? Unlikely.

On board systems hacked/aircraft remotely flown

Malware was installed on the aircraft onboard systems. It enabled remote access to hackers that maneuvered the plane.

Although hacking an aircraft system is theoretically possible, it seems that shutting off some of the onboard systems leaving no time for the crew to use any emergency one is a bit too much. Even if the possibility to hack remotely piloted aircraft is actual, it would require a massive operation to use satellites to give inputs to the aircraft once under remote control. Such operation would leave traces (on satellites, for instance).

Aircraft shot down

The aircraft is hijacked, is turning towards a sensitive target. It is shot down.

We’ve extensively discussed it here. Unlikely. Even less likely, considering where search forces are currently focusing.


One of the pilots hijacked the plane to commit suicide

It can’t be ruled out but it seems unlikely, considered where the aircraft could have crashed. There are no messages left behind by pilots.

Subscenario: the pilot decided to do something about Anwar Ibrahim, Malaysia’s opposition leader. First he disables the systems, turns the aircraft west out of radar and cell phone range, then, using a satellite phone, contacts PM and demands they reverse the Anwar conviction (or some other demand) or he will crash the plane.


An airworthy aircraft disappered from radars and stopped communicating with Air Traffic Control at the boundary between Malay and Vietnamese ACC areas of responsibility.

For reasons we still don’t know the aircraft radio systems did not work while the plane flew westwards back towards Malaysia.

Even if information was uncoherent and sometimes contradictory, we know for certain that military radars in both Malaysia and Thailand saw the plane.

In spite of all the disabled onboard systems, satellite got a signal of presence of the aircraft for each hour until 8:11AM LT, +7 hours after take off.

For several days, search efforts focused on the wrong area.

The aircraft wreckage was not found but searches in the South Indian Ocean have been intensified. US sources pointed to the Indian Ocean since the beginning. USS Kidd moved there few days after the aircraft disappeared.

This incident could cause some aviation procedures to change to reflect the inability of authorities to react to hijacking attempts conducted by experienced crew members (regardless of whether either of the pilots is found guilty or not).

All the articles about MH370 can be read here (scroll down).

H/T to all my visitors and readers for providing tons of information and hints. A big thank you for the help by staff member “rcair1” who filed an almost daily summary with the latest findings on His Sanity Checks helped shed some light on tecnical and non-technical details.

malaysia-mh-370 debris

Image credit: Reuters/Jason Lee, Washington Post, Australian Governement


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About David Cenciotti
David Cenciotti is a journalist based in Rome, Italy. He is the Founder and Editor of “The Aviationist”, one of the world’s most famous and read military aviation blogs. Since 1996, he has written for major worldwide magazines, including Air Forces Monthly, Combat Aircraft, and many others, covering aviation, defense, war, industry, intelligence, crime and cyberwar. He has reported from the U.S., Europe, Australia and Syria, and flown several combat planes with different air forces. He is a former 2nd Lt. of the Italian Air Force, a private pilot and a graduate in Computer Engineering. He has written five books and contributed to many more ones.


  1. One thing that hasn’t been proposed by people is that the “hacking scenario” could have occurred on the flight. E.g. there is a vulnerability whereby a passenger can gain access to the electronics cables from a bathroom or certain seat and then use his high equipped computer to control and disable the plane. Unlikely, but more likely than the “remote hacking” scenario.

  2. ELT was explained but in the summaryof facts I cannot locate any mention of the ELT. Was this aircraft equipped with ELT? From what I understand, ELT are not mandatory for airliners.

  3. I have seen several “fast moving” electrical fire theories which sound good on the surface. Can anyone with serious flight experience confirm or deny the plausibility of these in this kind of circumstance?

  4. A very impressive veneer of objectivity, Avationist. It begs to be looked at more closely, not so much on technical grounds (which are surely beyond reproach or so it would seem) as on grounds of logic.

    Much has been been made of the unimpeachable nature of these important pings. Yet Inmarsat have described their discovery as a Doppler process:

    They don’t give location such as Longitudinal/Latitudinal co-ordinates The signal merely takes longer to reach the geo-stationary satellite as the plane recedes. So a ping timed as being expected at the satellite at say 8.11, takes several moments longer than one timed to arrive at 5.11. Analysis of this increasing time difference places the plane at a growing distance between satellite and plane, right? Like hearing the note of a travelling load vehicle as the note falls as it gets further away. Simples, yes?

    It doesn’t show where the plane was at that moment with respect to our Long’Lat co-ordinates. That is sheer graphical make believe.

    Therefore the ‘corridor graphic we have been fed exclusively on recently is misleading. The satellite’s field of coverage may well be circular – but it cannot be inferred from that that MH370 was following a path similarly circular and clockwise. If anything Inmarsat’s data field, as displayed here onTV in the UK, appear to show a southward leading track considerably to the west of the one generally made available to us by the world’s media.

    Further to the west of Malaysia and Sumatra, closer to southern India, closer to Mahe, The Maldives and indeed Diego Garcia. In fact a much longer journey all around.

    Where in that case did it refuel?

  5. I call ‘bull’ on the doppler effect of pings CONFIRMING FOR A FACT that the plane ended in the southern ocean. How much data is in a ping? I doubt there is much data there to begin with. Ping, Ack. Its like a dozen or so bytes in each direction. Even if its redundantly transmitted which is not stated anywhere, it would be still be a tiny amount of data. Plus to meaure doppler you need the minute changes in frequency of the carrier signal from the plane. So we are expected to believe the satellite records the exact frequency of the carrier received from every plane it talks to, and not just the data carried?

    But even if it does, how can Doppler confirm southern hemisphere over northern? Doppler measurements can only tell if the object is approaching or retreating from the listener and at what speed if we know the frequency being sent. AND we are talking about the doppler shift of the inmarsat ping response carrier frequency which is travelling at the speed of light from an object moving at a maximum velocity of 950km/h. Really.

    Apparently we now have radical new technology that allows us to triangulate a brief and sporadic signal using a single antenna and doppler.

    If they had said, we looked at signal strength because our coverage over open sea is not good because we focus our antennas at the land i would be more convinced. But Doppler???

    Where are the arcs for 2:11, 3:11 and 4:11?? Why has that data been withheld?

    If all the pings were known, then using the maximum cruisng speed of the plane, its minimum cruising speed and the ping timings starting at 2:11 two possible flight corridors could be reasonably accurately calculated provided its assumed the plane didnt end up flying in circles somewhere or with excessive serpentine patterns.

    Apparently the 2:11 arc corresponds with the last radar trace which ended at 2:15 with the plane flying North West. But that data is withheld.

    The inmarsat spokesperson is quoted as saying “The ping timings got longer”.

    How did the plane not have to take a sharp deviation south from its last “known?” flight path and cross Indonesian airspace?

    How did it fly around all of indonesian radar in one hour, such that the 3:11 ping was “longer” than the 2:11 ping?

    I think its more likely that no country on the northern corridor wants to admit they cant really track a plane against the giant wall of mountains called the Himalayas. Or that, unless the track exhibited a clear threat it would be ignored. Or that, it was night time, the radar was off, or unmanned, so they didnt see it till morning, if at all. What country wants to admit to holes in it security? Certainly not Malaysia, even when they are obvious to a casual observer. (Stolen Passports???)

    If it flew north it must of landed because there is no ELT transmission. The political and military implications of the plane flying north are massive and no one involved wants it to be so. Unless and until a piece of the plane which would render it un-servicable is found in the ocean it can never be “known” where the plane went. Otherwise the next headline will be “”Unidentifiable 777 involved in ??? but experts confirm it couldn’t have been MH370 because it crashed in the ocean and was unrecoverable.”

    But most damning of all in this whole debacle is the international aviation industries ignorance of the recommendations from the second interim report on FA447.

    I don’t buy that tracking planes securely and in real time is “too much data”, that’s crap. It is well within the realms of practical implementation to live stream cockpit AND cabin video feeds, plus realtime telemetry data for every commercial plane in the air and for it to not be able to be disabled by pilots. Why only cockpit “voice” recorders. What cant we record video? If us planes can be equipped with Wifi for passengers to use its not because doing this is not doable, its because international aviation just doesn’t want to do it. For whatever the reason. Have interntional aviation not heard of EPIRB?? My crappy yacht had to have one by law, but a 777 can crash in the ocean and it doesn’t need a locator bouy to be deployed so it can be found. Oh and apparently its too difficult for that locator bouy to have some flash in it with a record of everything that happened on the plane.

    If peoples lives were not involved it would be a massive joke as it stands international aviation and our ability to track and monitor commercial aircraft is a dangerous farce.

    • I speculate the US has a vast array of undersea microphones to track submarines and the crash was “heard” in this region. Obviously the US is not going to volunteer this information so the cover story emerges of this “pings”.

      I would like to see a test done of a known aircraft with known locations to see if they can locate it based on the same to “verify” the process.

      And then there is the first reported issue of 2500 miles worth of fuel. Did the plane land and offload passengers, hardware etc and then take off again refueled to be flown and dumped into the southern oceans?

      And yes, where are the first pings? Probably withheld because they would not make sense!

      There is definitely some kind of strange response from officials on this matter making it I think at least a sad but fascinating mystery.

    • Yes, it’s my understanding that each plane (acars unit) has a specific freq. Even if not a separate carrier freq, it can be subbanded out. Using PRF and PRI (and signal strength) one could identify the particular “ping.”

      The northern track was discounted because the satellite was SOUTH of the last known location (south of a due west flightpath.) Ergo… northern track would NOT show the compression of signals that identified that the aircraft was flying CLOSER to the satellite. Since the signal WAS compressed (for a short while,) it is deduced that the plane was headed in a southerly direction (towards the satellite) before flying away from it.

      But, the ONLY thing that “places” the plane so far south is an “estimate” of speed and altitude. Since we don’t KNOW what these were, we must consider the ping data has identified a possible location on a direct vector down the Strait of Malacca, towards KL… but passing by it due to incapacitation of the pilot. Otherwise, he would have landed it there.

      The plane is either in the water south of Java Island OR in the desert of Northwest Australia.

      • I don’t follow your logic regarding the discounting of the possible northern track. Mind you, I don’t believe the plane flew north (it would have been picked up by numerous radars). But given that the aircraft was always well east of the subsatellite point, there is no way to differentiate between an aircraft flying northwest (and slightly closer to Inmarsat) vs. southwest (and also closer).

        Toward the latter part of the flight, the ping rings were increasing in radius and the Doppler frequencies were shorter. But again, all this means is that the aircraft’s range rate was positive (i.e. increasing).

        • I apologize for the fact that I can’t use technical language and details to support my theory, but let me see if I can explain. First, there has been precious LITTLE intel to be gleaned from media reports, but just once I heard someone from Inmarsat (or someone quoting them?) that said (paraphrasing) that “this” would explain why the first few pings showed the plane getting closer to the satellite and then getting farther away. Not sure if they meant 2:11 and 3:11, which were obviously getting closer if it was tracked heading west… or the intermediate pings following the last “suspected” radar location. Assuming the latter, consider this:

          IF the equator is Main street on a due east/west heading, and the last known radar contact is at 3rd street NORTH… (and the plane was heading west on that street…) the satellite is at 1st street SOUTH. For purpose of simplification, assume a left or right turn of 90 degrees on a north/south street (3 hours east of the satellite.) Using simple geometry, the distance from the satellite (return of signal time) would be shorter at 2nd street NORTH (left turn) than it would be at 4th street NORTH (right turn.) … [one block later at the next ping.]

          Since the plane was NOT on a due heading towards the satellite, and assuming only ONE heading (relative to the bearing of the plane) could or would have been made from the last known radar contact… ANY heading north of the last known bearing would “decompress” (or expand) the doppler shift (compared to the “expected return) whereas the SAME deviation/heading south (towards the satellite or equator) would “compress” the doppler shift.

          For this, and many other reasons (including comparison to other known aircraft at the time both north and south of the equator,) and IF I heard them right about a temporary decompression of signal return (before it again started getting further from the satellite, I believe the last turn was towards the south.

          I just don’t believe the “assumed” plots at the 5:11 and subsequent pings, because I don’t believe the aircraft was at top speed (or even close.) Even “they” have revised the speed downward, hence the quick shift to a search area eastward UP the southern “arc.” Now… they have moved another time (or two) northeastward along that arc. Eventually… they will get to the northernmost point (south of Java) and the batteries on the black box will have expired.

          I am not a satellite expert (as so many here seem to be.) I “was” an Intel collector/analyst, both comint and elint. Since there is so little believable “data” released so far, I am taking a stab in the dark, so to speak. I flew (a “backender” on) RC135’s (predecessor to the P-8.) I flew NRO satellites prior to the Trumpet generation. I was on duty the night the F-111’s attacked Libya and “may” have saved some pilots that night with my search and identification of known SAM locations and launch modes. But, that was years ago.

          Now, I’m just a frustrated old man trying to cut through the B.S. I hear on the news! lol. I keep coming back to Occam’s Razor. How many hijackings OR pilot suicides have matched this scenario? None. How many inflight explosions have left no evidence? None. How many terrorist attacks were so brazen and expected to happen later? None. How many unexplained disappearances of aircraft? Very few. How many inflight emergencies that pilots tried to save the aircraft and the lives of the passengers and crew? HUNDREDS!

          I developed a theory that MIGHT BE WRONG and am trying to find data to support OR eliminate it. It wouldn’t be the first time if I was wrong. lol. But… they ARE moving the search area closer to where I expect the plane to be. And the ONLY thing that allows them to do this, is speculation that the airspeed might have been slower. That, alone, changes the “expected” flight path.

          Could the aircraft have flown down the Strait of Malacca, at 5-12,000 feet and not be seen by Indonesian or Malaysian radar? I think so. [Without transponders, it was just a small blip.) But, neither would admit it! Have we heard much of anything but posturing by Indonesian officials?

          Could the pilot or F.O. have been involved in some plot that there is NO “chatter” about anywhere? I doubt it! Even the 9-11 hijackers left an intel trail!

          I don’t know what happened! But, I haven’t heard anything yet that discounts my theory.

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