Ten Years Since the Disappearance of Malaysia Airlines flight 370

8 Mar 24 11 Comments

This week’s guest post is not actually here. It’s over at the Guardian: MH370: one of aviation’s biggest mysteries remains unsolved 10 years on by Oliver Holmes.

I first spoke to Oliver a few years back when he was writing a different piece on the loss of Malaysia Airlines 370, and I was impressed with his curiosity and thoroughness. When he contacted me about this article, I was less excited. Quite honestly, I didn’t think I had anything new to say about the issues, other than a few muttered comments about the Netflix special and lack of basic fact checking.

There’s a lot of excitement about Ocean Infinity’s push to reopen the search, and of course, it would be amazing if the wreckage of the Boeing 777-200ER was found, let alone the data recorders. Technology has moved on over the past ten years and perhaps there really is an opportunity to discover something new. But I keep returning to Air France 447, where they knew exactly where the aircraft had entered the Atlantic and yet still spent two years searching a 4,000 km2 area. Only once the search area was reduced to 75 km2 did they finally discover the data recorders.

Amazing map of the search areas for Malaysia Airlines Flight 370 in the Southern Indian Ocean by Andrew Heneen.

In the case of Malaysia Airlines flight 370, the Cockpit Voice Recorder is highly likely to have two hours of silence, as we have no reason to believe that there was any manual control of the aircraft for the final five hours of the flight. The FDR will have something for us, presuming it has survived, but whether that data will explain what happened that day in the cockpit is another story.

So, I regretfully wrote Oliver that although we had learned much from this tragic situation, I had nothing new to say.

Oliver immediately emailed me back and asked a great question: What have we learned? That was much more interesting to me (he’s really good at that), with the result that I wrote him half a novel. I always consider these opportunities to be like an iceberg — I know most of what I write will never see the light of day, but I like to hope that it will hope inform the final piece and give the journalist a better idea of some of the not-so-obvious issues. Oliver, if you are reading this, I’m sorry!

I realised today that I could share the longer version with you! This is excerpted from the email.

The most practical change is to the Underwater Locator Beacons. These beacons help SAR (search and rescue) find survivors when an aircraft crashes into the sea. They transmit a ping on a specific frequency every second, with a detection range of 1-2 kilometres under normal conditions at full strength. However, the beacons installed on the accident aircraft were due for an overhaul; Malaysia Airlines claimed that the batteries didn’t need replacing for a few more months, but it called into question how long the beacons would keep broadcasting. With the aircraft at the bottom of the Indian Ocean, only the full-power signal would be detected, which meant they had at best thirty days to try to pick up the pings from directly over the aircraft.

EASA released new proposals for underwater locating detectors, which have since been adopted. EASA now requires all commercial airliners operating over oceanic areas to have an Underwater Locator Beacon which will transmit full-strength for at least 90 days. Skybrary’s ULB page has more details.

I mentioned the Inmarsat flight tracking in yesterday’s mail. What’s exciting is that we discovered that this would even be possible. When MH370 was first reported missing, the search centred on the South China Sea, based on the last communication from the flight crew. Then Inmarsat released the bombshell that they continued to receive faint pings from the MH370 ACARS system. This meant that the Boeing 777 was still flying for seven hours after it had dropped out of contact. Only after this information had gone public did the various military installations confirm that they’d seen something on primary radar.

Satellite data had never been used to track an aircraft before; however, in this case, it was critical as the data analysis proved that the aircraft had gone south after coming around Malaysia, moving the search to the Indian Ocean. This was proved correct through other evidence, most recently, the pieces of aircraft debris that drifted on shore. That early information could have been critical; no one knew it was possible at the time.

Eventually, debris washed to shore and some 18 pieces were confirmed as almost certainly from the wreckage of MH370. The analysis of the flaperon found on Réunion led to scientists from all over the world analysing tide data and drift modelling in unprecedented numbers. One of my favourite aspects is that the barnacles were the right age to have attached after the crash and were only recently dead (with “a strong odor”) The Ars Technika article from 2023 is a bit easier to follow and explains how the age and type of the barnacles found on the flaperon might tell us more precisely where the flaperon started.

An interesting connection came up just a few weeks ago. At the time, The Australian Transport Safety Board concluded that over the five hours when MH370 was travelling south, there was no evidence of manual changes, leading most to believe that by now, the flight crew was unresponsive. This is similar to the “ghost flight” of Helios Airways flight 522, which crashed in 2005 after the flight crew were incapacitated by hypoxia.

Last month, the door plug fell off of Alaskan Airlines flight 1282: as the cabin depressurised, the pilots were taken by surprise when the flight deck door burst open. Cockpits have been kept locked since the “9/11” attacks in the US despite some concern about access to the cockpit in an emergency. The NTSB reported that Boeing had confirmed that in the case of a depressurisation event in the cabin, the flight deck doors on the Boeing 737 MAX automatically spring open to release pressure on the cockpit. Speculation is that this had not been documented to avoid it being used by nefarious characters to access the flight deck. Personally, I suspect that, as with other features of the MAX, it was not seen as critical information that the pilots needed, so Boeing didn’t include it in the pilot documentation.

Either way, this is clearly a response to multiple cabin decompression instances, including potentially MH370. One of the theories (which I don’t see as likely) is that the captain of MH370 deliberately depressurised the cabin to quickly disable the passengers. This would be a bad idea in the Boeing MAX as the flight deck door would open, allowing easy access to the rogue pilot.

It may also be worth looking at the length of the cockpit voice recordings. This subject is in the news again from the aftermath of Alaska Airlines flight 1282: NTSB: Retrofit all Cockpit Voice Recorder-Equipped Airplanes With 25-Hour CVRs.

Originally, cockpit voice recorders kept just thirty minutes of the audio; this was later expanded to two hours. In Europe and the UK, as a direct result of MH370, aircraft built after 2021 have recorders that hold twenty-five hours of data: CAA regulations: cockpit voice recorder (also mentions the 90-day underwater beacon).

However, this isn’t the case in the US. Although the NTSB doesn’t mention MH370, it is another example where the two-hour limitation is a serious hindrance. Even if we recovered the digital recorders (CVR and FDR) from MH370, the cockpit voice recorder likely only recorded two hours of silence from the unresponsive pilots. We’d know more from the parameters recorded on the Flight Data Recorder, so it would still be helpful! But most of us want to know why the aircraft turned off course in the first place. Without the audio from the cockpit, we might never have the answer to this, even if we had the “black boxes”.

So, as we look over the past ten years, what else do you think has changed as a result of the disappearance of Malaysia Airlines 370? What might I have mentioned that I forgot?

To save you scrolling up, Oliver’s piece is here: MH370: one of aviation’s biggest mysteries remains unsolved 10 years on. If you’ve seen additional articles on the subject that you think we might like, please feel free to leave them in the comments!

Category: Miscellaneous,


  • Hi Sylvia,

    Great writeup, thank you.

    I’d like to offer some details on the fact that the cockpit door unlocks in case of a depressurisation. I’m not familiar with the manuals of the 737, but in case of the A320 this isn’t unknown at all, it’s well documented and part of the training materials for both cockpit and cabin crews. Although I started flying after MH370, I’d be very surprised if this functionality was a reaction to MH370 or other recent pressurisation issues as it doesn’t seem to be any kind of recent retrofit.

    As far as I was told, the door opens to allow equalizing the pressure between the cockpit and the cabin in case of a rapid depressurization (e.g. by a door being blown out at cruise altitude). Otherwise, the heavily fortified cockpit door might be ripped from its frame by the extreme pressure difference and fly into the cockpit or the cabin, causing catastrophic damage. I suspect the feature was added when the cockpit doors became fortified after 9/11, as they weren’t robust enough before that to warrant the feature.

    To enter the cockpit in case of a flight crew incapacitation (for any cause), the cabin crew can enter their emergency access codes that open the cockpit door after some time if the request is not actively denied by the flight crew. This is the dedicated functionality for emergency access to the flight deck (and also available on a 737 or any other modern aircraft), not the automatic opening in case of a depressurization.


    • Interesting! I’m definitely going to have to look into this further, as it does seem to have taken Boeing 737 pilots by surprise. I admit that the connection was rather tenuous!

      There’s a theory that gets bandied about that Captain Zaharie Shaw purposely depressurised the cabin, in which case one would assume he would actively deny any attempts to open the cockpit doors. I’m not sure this is even possible but I suppose, thinking it through, that it wouldn’t be rapid enough to open the cockpit doors automatically.

      • It’s definitely possible to depressurise any airplane from the cockpit. For some aircraft, you’d have to manually open the outflow valve, others even have an emergency depressurisation button that does it. It’s used for a number of abnormal situations that either require the crew to manually control the cabin altitude or rapidly depressurise the cabin in case of e.g. severe smoke in the cabin.

        I’m not quite sure if the door automatically opens in case of a slow depressurisation (or, for that matter, if the 777 door opens at all); but even if it does, it would be difficult to notice. The door doesn’t spring open or anything like that, the lock just unlocks with a pretty quiet click noise. If no one tries to open the door during that time, you wouldn’t notice that it’s unlocked. It might even be possible to manually lock it again after it auto-unlocked in case of a depressurization.

        It would not take long for the occupants to become unconscious (about 20-30 seconds) at cruise altitude, but they would certainly notice: The masks would drop and last for about 15 minutes and at least some of the cabin crew would probably manage to don their portable oxygen systems. During this timeframe at least, the door would have to be locked to prevent everyone from going to the front to see what’s wrong.

        Although Langewiesche was quite sure about it, I agree it’s hard to see how to pull it off.

  • Sylvia, regarding MH370, there was an article in Ham Radio magazine “QST” some time in Spring/Summer 2022 about a Ham who used a Ham Radio mode called WSPR to get a more precise location of the splashdown, and using his data Australian officials and others were interested if funding could be obtained to search again in the smaller area he had defined. If I remember correctly, he had used records of Ham Radio connections via the WSPR technology to determine a more precise actual
    speed of light through the portion of the ionosphere where MH370’s engine monitor beacons were last heard. Unfortunately, that calculation put the likely location in a much smaller area close to the very eastern end of the arc that had been searched before, but in depths of around 14,000 feet.

    • That’s a very controversial method, to put it lightly.

      Their process is basically this:
      • we have this huge database of links
      • the links sometimes have anomalies, but these don’t give any location
      • so, using established data, we’re picking anomalous links that would’ve crossed the possible flight path of MH370, and claim the anomaly was caused by that aircraft specifically
      • the result is a highly erratic flight path
      • we imagine the pilot was disoriented, but somehow kept the aircraft at altitude, and even recovered from a dive, yet never once used the radio
      • we don’t explain why or how the pilot turned off the transponder and flew to IGARI, avoiding civilian radar as best he could, and only began flying erratically after he turned off that route
      • we never consider other sources of WSPR anomalies, including hundreds of other aircraft in flight at the time.

      This analysis is based on wishful thinking, and disregards the fact that aircraft scatter is too weak to be detected by WSPR over long distances.

      More details at https://mh370.radiantphysics.com/2021/12/19/wspr-cant-find-mh370/ . If you wish to discuss this further, I suggest the existing thread on the Metabunk forum.

  • Relevant comments, copied from the Feb 16 blog post:


    One thing I was thinking about today was that in 2014, after the MH370 disappearance, there was a lot of talk about ejectable digital recorders, which might give a better chance of retrieval in some conditions. Also, Inmarsat was very excited about offering free global tracking by satellite. I can’t remember the last time I heard about either of these.


    I tried to look into it, and believe the ADS-C service does global tracking. The crux here is that there are always ways to turn a system like that off.

    Inmarsat planned to offer a free position every 15 minutes with their basic service, which most commercial airlines have to allow pilots to “phone” their company. ADS-C seems to be included with that service now.

    I believe Airbus began installing an Automatic Deployable Flight Recorder (AFDR) on the A-350 in 2019 (and presumably other models). They’re built by Leonardo DRS.

    • I want to ask the girl who recieved the phone call from his father can be tracked. No one noticed that

  • Hi Sylvia,
    Another considered overview that, rather than so many so-called expert articles, raises thought provoking avenues for further study without sensationalism.
    Having said that MH370 does raise the grim possibility that malicious intent by a member of the flight crew COULD have been the cause of loss.
    It has happened before, probably more than we know, given past limitations of crash investigation. As we know all air accidents are the result of a chain of events, and advancing and sharing our knowledge of them should reduce their happening again. But do airlines share anonymised data on flight crew behaviour that has led to correction, re-training, monitoring, sanctions and dismissal so rogue pilots can be identified?

  • Wow. I guess my recollection of the glance I made at that QST article was opening a HUGE discussion, and has at least peaqued my curiosity about what the article said, and how it relatedd to the education I just got from reading the preceding comments. It does appear that I completely misunderstood the QST article or I’m thinking of another discourse I skimmed over almost two year ago. That having been just a couple of months before we sold house and moved, dumping all of my QST and other technical magazines and then starting aa health decline… we, I apparently placed a comment I shouldn’t have, considering I didn’t really know what I was talking about. But, with a few of my firneds I AM still re-stating the story of the crash of Alaska Airlines Flight 66 at Juneau on 4 Sept ’71, to hopefully erase the FAA’s (and thus NTSB;s) short-sighted conclusion (or non-clonclusion) as to cause. Stay tuned, and thank you for the delightful but intense education on WSPR.

    • I apologize for giving you a (mostly) copy&paste answer earlier. Thankfully, that huge discussion happened elsewhere and earlier! I expect there are many people like you and the then editors of QST who are not aware that there even is a debate. I don’t really know what I’m talking about, either, but I had the advantage of having both read Victor Iannello’s analysis (linked above) and Richard Godfrey’s original theory (see mh370search.com for that) some time ago.

      As MH370 theories go, the WSPR one is actually fairly benign. Last summer, there was a huge flap in UFO circles about an older hoax video that allegedly showed MH370 abducted to another dimension via a portal that turned out to be a stock video effect. But for a moment, conspiracy theorists thought they had discovered the biggest “government coverup” since Roswell.

  • Sylvia, here is an interesting article on a ‘biological’ approach to try and find the crash location… Published 7 Mar 24 and titled: “The Sea Creatures That Opened a New Mystery About MH370 Could freaky barnacles do what advanced technology couldn’t — find the missing plane?” Article focuses on using barnacles to identify time and location. And as you will read the data is inconclusive and raises more questions than answers but then again maybe more clues.


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