Category: Aviation

In last month’s New York magazine article about Zaharie Ahmad Shah’s flight simulator, I cautioned against treating the recovered data as a smoking gun:

…it’s not entirely clear that the recovered flight-simulator data is conclusive. The differences between the simulated and actual flights are significant, most notably in the final direction in which they were heading. It’s possible that their overall similarities are coincidental — that Zaharie didn’t intend his simulator flight as a practice run but had merely decided to fly someplace unusual.

What I failed to question was the report’s assumption that the six points all belonged to a single flight path. On closer examination that assumption seems ill supported. Rather, it seems more likely that the six points were recorded in the course of  two or possibly three separate flights. They were interpreted as comprising a single flight only because together they resembled what investigators were hoping to find.

The first four points do appear to show a snapshots from a continuous flight, one that takes off from Kuala Lumpur and climbing as it heads to the northwest. Between each point the fuel remaining decreases by a plausible amount. Each point is separated from the next by a distance of 70 to 360 nautical miles. At the fourth point, the plane is at cruise speed and altitude, heading southwest in a turn to the left. Its direction of flight is toward southern India.

The fifth and sixth points do not fit into the pattern of the first four. For one thing, they are located more than 3,000 miles away to the southeast. This is six or seven hours’ flying time. Curiously, at both points the fuel tanks are empty. Based on its fuel load during the first four points, the plane could have flown for 10 hours or more from the fourth point before running out of fuel.

The fifth and sixth points are close together—just 3.6 nautical miles apart—but so radically different in altitude that it is questionable whether they were generated by the same flight. To go directly from one to the other would require a dive so steep that it would risk tearing the aircraft apart.

The picture becomes even more curious when we examine the plane’s vertical speed at these two points: in each case, it is climbing, despite having no engine power.

The ATSB has speculated that in real life MH370 ran out of fuel shortly before 0:19 on March 8, and thereafter entered into a series of uncontrolled porpoising dives-and-climbs called phugoids. In essence, a plane that is not held steady by a pilot or autopilot, its nose might dip, causing it to speed up. The added speed willl cause the nose to rise, and the plane to climb, which will bleed off speed; as the plane slows, its nose will fall, and the cycle will continue.

Could a phugoid cause a plane to climb—663 feet per minute at point 5, and 2029 feet per minute at point 6? The answer seems to be yes for the fifth point and no for the sixth. Reader Gysbreght conducted an analysis of 777 flight-simulator data published by Mike Exner, in which an airliner was allowed to descend out of control from cruise altitude in the manner that the ATSB believes MH370 did.

A diagram produced by Gysbreght is shown at top. The pink line shows the plane’s altitude, starting at 35,000 feet; the blue line shows its rate of climb. Worth noting is the fact that the phugoid oscillation does indeed cause the plane to exhibit a small positive rate of climb soon at first. But by the time the plane reaches 4000 feet — the altitude of the sixth point — the oscillation has effectively ceased and the plane is in a very steep dive.

Gysbreght concludes:

As expected for a phugoid, the average rate of descent is about 2500 fpm, and it oscillates around that value by +/- 2500 fpm initially. The phugoid is apparently dampened and the amplitude reduces rapidly. I was slightly surprised that it reaches positive climb values at all. Therefore I think that 2000 fpm climb is not the result of phugoid motion.

Not only is the plane climbing briskly at the sixth point, but it is doing so at a very low airspeed—just above stall speed, in fact. If the pilot were flying level at this speed without engine power and pulled back on the controls, he would not climb at 2000 feet per minute; he would stall and plummet. In order to generate these values, the plane must have been put into a dive to gain speed, then pulled up into a vigorous “zoom climb.” Within seconds after point six, the simulated flight’s speed would have bled off to below stall speed and entered into an uncontrollable plunge.

Perhaps this is why Zaharie chose to record this particular point: it would have been an interesting challenge to try to recover from such a plunge at low altitude.

What he was doing at points 5 and 6, evidently, was testing the 777 flight envelope. This might seem like a reckless practice, but I think the opposite is the case. From time to time, airline pilots do find themselves in unexpected and dangerous conditions. For instance, as Gysbreght has noted, “On 7 october 2008 VH-QPA, an A330-303, operating flight QF72 from Singapore to Perth, experienced an In-flight Upset west of Learmonth, West Australia. The upset was caused by a freak combination of an instrumentation failure and an error in the flight control software, which resulted in an uncommanded pitch-down. The vertical acceleration changed in 1.8 seconds from +1 g to -0.8 g.” It would be better to experience a situation like this for the first time in a flight simulator in one’s basement, rather than in midair with a load of passengers and crew.

What Zaharie clearly was not trying to do was to fly to McMurdo Station in Antarctica, as some have speculated.

For one thing, while a 777 is fully capable of flying from Kuala Lumpur to Antarctica, it was not carrying enough at point 1 to make the trip. And if one were trying to reach a distant location, one would not do so by running one’s tanks dry and then performing unpowered zoom climbs.

The misinterpretation of the flight simulator data offers a couple of cautionary lessons. The first is that we have to be careful not to let a favored theory color our interpretation of the data. The investigators believed that MH370 flew up the Malacca Strait and wound up in the southern Indian Ocean, and they believed that Zaharie was most likely the culprit; therefore, when they found data points on his hard drive that could be lumped together to form such a route, that’s what they perceived.

A second lesson is that we cannot uncritically accept the analysis made by officials or by self-described experts. Science operates on openness. If someone offers an analysis, but refuses to share the underlying data, we should instinctively view their claims with suspicion.

Last month, I published an article in New York magazine about a secret Malaysian police report which included details of a simulated flight into the southern Indian Ocean. As Victor Iannello revealed in a comment earlier today, that information came from French journalist Florence de Changy, who had come into possession of the full police report but only shared a portion of it with me.

I have not seen the full report, but would very much like to, because I would like to form my own judgement of what they mean, and I think everyone who is interested in trying to figure out what happened to the missing plane, including the next of kin, are entitled to the same. Some people who have read the full reports have suggested that they give the impression that the recovered simulator files do not in context seem all that incriminating. Other people who have seen the full report have told me that the report contains material that makes it hard to doubt that Zaharie is the culprit. Of course, it’s impossible to rely on someone else’s say-so. We need to see the full report.

The reason I am writing this post now is that earlier today Florence published an article in Le Monde in which she describes having the full report as well as another, 65-page secret document on the same topic. Meanwhile, another French newspaper, Liberation, has also published an article indicating that they, too, have a copy of the report. And private correspondence between myself and a producer at the television network “France 2” indicates that he has as well.

Meanwhile, I know that independent investigators here in the US have the documents as well.

At this point, the secret documents are not very secret. Someone within the investigation has been leaking them like crazy, obviously with the intention that their contents reach the public. My understanding is that this source has placed no restrictions on their use. So journalists and independent investigators who have copies of these documents need to do their duty and release them — somehow, anyhow. Some people that I’ve begged and implored to do so have said that they fear legal ramifiations. Well, if it’s illegal for you to have these documents, then you’ve already broken the law. Use Wikileaks or another similar service to unburden yourself.

Free the data!

UPDATE 8/14/16: Apparently Blaine Alan Gibson has the document, too, according to a rant he post on Facebook. He reveals that the entire set of documents is 1,000 pages long.

The general-interest media has seized hold of a debate that his been raging on this forum for quite some time: after the last communication between MH370 and the Inmarsat satellite at 0:19, did the aircraft spiral unpiloted into the sea close to the 7th arc, or glide into the ocean under pilot control with the flaps deployed for a gentle, Miracle-on-the-Hudson type touchdown?

The answer is: neither.

I’ll explain why, but let’s back up a bit first. In the picture above, taken from the ATSB report “MH370 – Definition of Underwater Search Areas,” released on December 3, 2015, we see the final sequence of events believed to have occurred before the plane vanished for good. Sometime around 00:02:30, the right engine ran out of fuel and flamed out. At 00:11:00, the satellite data unit (SDU) transmitted its scheduled hourly ping as usual. A few minutes later, at 00:17:30, the left engine ran out of fuel and flamed out. This caused a systemwide electrical supply failure, and the SDU powered down along with everything else.  The ram air turbine (RAT) deployed to provide emergency hydraulic and electrical power—but this would not include the SDU or the flaps. One minute later, the APU kicked in and restored electrical power, and a minute after that, the repowered SDU logged back in with Inmarsat, creating the “7th ping.” Then, within seconds, the APU exhausted the dribble of fuel in its fuel lines, and the SDU lost power again.

When the 7th ping occurred, therefore, the plane had been without engine power for two minutes, and had spent approximately 15 minutes before that slowing and descending from cruise speed and altitude under the power of a single engine. Thereupon, it descended without autopilot inputs. So: what happened next?

Continue reading Did MH370 Plunge or Ditch?

Here’s a link to the report broadcast today on Australian 60 Minutes about the search for MH370. Part 1:

Part 2:

Discussion after the jump…

Continue reading 60 Minutes Australia on Secret Malaysia Report

In a posting to a section of its website called “Correcting the record,” the Australian Transport Safety Board today confirmed that the FBI found data on MH370 captain Zaharie Shah’s flight simulator hard drives indicating that Zaharie had practiced a one-way flight into the southern Indian Ocean, as I wrote in a story for New York magazine on Friday. Entitled “False and inaccurate media report on the search for MH370,” the post concerns several claims by Australian pilot Byron Bailey in The Australian, including Bailey’s interpretation of the flight-sim data:

Mr Bailey also claims that FBI data from MH370 captain’s home simulator shows that the captain plotted a course to the southern Indian Ocean and that it was a deliberate planned murder/suicide. There is no evidence to support this claim. As Infrastructure and Transport Minister Darren Chester said in a statement, the simulator information shows only the possibility of planning. It does not reveal what happened on the night of its disappearance nor where the aircraft is located. While the FBI data provides a piece of information, the best available evidence of the aircraft’s location is based on what we know from the last satellite communications with the aircraft. This is indeed the consensus of international satellite and aircraft specialists.

While ostensibly rebutting Bailey’s claims, the ATSB tacitly acknowledges the fact that the flight-sim data was in fact found by the FBI.

 

New York has obtained a confidential document from the Malaysian police investigation into the disappearance of Malaysia Airlines Flight 370 that shows that the plane’s captain, Zaharie Ahmad Shah, conducted a simulated flight deep into the remote southern Indian Ocean less than a month before the plane vanished under uncannily similar circumstances. The revelation, which Malaysia withheld from a lengthy public report on the investigation, is the strongest evidence yet that Zaharie made off with the plane in a premeditated act of mass murder-suicide.

The document presents the findings of the Malaysian police’s investigation into Zaharie. It reveals that after the plane disappeared in March of 2014, Malaysia turned over to the FBI hard drives that Zaharie used to record sessions on an elaborate home-built flight simulator. The FBI was able to recover six deleted data points that had been stored by Microsoft Flight Simulator X program in the weeks before MH370 disappeared, according to the document. Each point records the airplane’s altitude, speed, direction of flight, and other key parameters at a given moment. The document reads, in part:

Based on the Forensics Analysis conducted on the 5 HDDs obtained from the Flight Simulator from MH370 Pilot’s house, we found a flight path, that lead to the Southern Indian Ocean, among the numerous other flight paths charted on the Flight Simulator, that could be of interest, as contained in Table 2.

Taken together, these points show a flight that departs Kuala Lumpur, heads northwest over the Malacca Strait, then turns left and heads south over the Indian Ocean, continuing until fuel exhaustion over an empty stretch of sea.

Search officials believe MH370 followed a similar route, based on signals the plane transmitted to a satellite after ceasing communications and turning off course. The actual and the simulated flights were not identical, though, with the stimulated endpoint some 900 miles from the remote patch of southern ocean area where officials believe the plane went down. Based on the data in the document, here’s a map of the simulated fight compared to the route searchers believe the lost airliner followed (see above).

Continue reading New York: MH370 Pilot Flew a Suicide Route on His Home Simulator Closely Matching Final Flight

It wasn’t supposed to end like to this. Earlier today, ministers from the three nations responsible for finding Malaysia Airlines Flight 370—Australia, China, and Malaysia—announced that they would stop looking for the lost jet once the current 46,000-square-mile search zone is completed this fall. The decision was essentially an acknowledgement that they’d come up empty-handed in their quest to find the plane that disappeared from the face of the Earth in March 2014 with 239 people on board. This after two years of official assurances that success was right around the corner.

Why had they been so confident in the first place? How could they have been wrong? And if the plane isn’t where it was supposed to be, where else could it have gone? We’ve gone through two years of clues and conspiracy theories and false starts. But to understand how we’ve come to this point, it’s necessary to review the clues that search officials possessed, and how they interpreted them.

Calculating the Direction of Flight

There were two reasons why investigators felt certain the plane had flown toward a specific area of the southern Indian Ocean. The first was publicly acknowledged, the second kept secret.

The first reason had to do with signals exchanged between the plane and an Inmarsat satellite. On the night of March 8, 2014, 40 minutes after takeoff, MH370 suddenly went electronically dark over the South China Sea. Every form of communication it had with the outside world was turned off. The plane then pulled a 180, flew back over peninsular Malaysia, headed up the Malacca Strait, and disappeared from radar.

Then, surprisingly, three minutes later, it began communicating again. A piece of equipment in the back of the plane called the Satellite Data Unit (SDU) sent a log-on request to an Inmarsat satellite perched in a geosynchronous orbit high above the Indian Ocean. For the next six hours, the SDU stayed in contact, automatically sending intermittent pings that were automatically recorded by Inmarsat computers on the ground.

Continue reading Popular Mechanics: Where Did the Search for MH370 Go Wrong?

One of the most misunderstood insights into the riddle of MH370 is how the plane’s final path can be derived from Inmarsat BTO data alone.

Recall that the data, which was generated after someone on board caused the Satellite Data Unit (SDU) to re-logon to the Inmarsat Satellite 3F-1 over the Indian Ocean at 18:25, comes in two flavors. The first, the Burst Timing Offset (BTO) data, reveals how far the plane is from the satellite at a given time. This can be mathematically converted into a set of “ping rings” along which the plane must have been at a given time. The BTO data is very well understood and fairly precise, providing an accuracy of within 10 km.

The second, the Burst Frequency Offset (BFO) data, is more more complicated and much fuzzier than the BTO data; its inherent uncertainties are equivalent to a position error of hundreds of miles. It doesn’t have a single physical correlate but is related to how fast a plane is going, what direction it is headed, and where it is located.

For a time after MH370 disappeared, searchers hoped that they could combine these two data sets to identify the area where the plane issued its final ping. After months of work, however, they determined that this would be impossible. The BFO data is just too vague. However, along with the bad news came some good: it turned out that by the clever use of statistics they could figure out where the plane went using the BTO data alone. The methodology developed by Australia’s Defense Science and Technology Group (DSTG) and explained in an ATSB report entitled “MH370 – Definition of Underwater Search Areas” released last December.

Many independent researchers do not understand the technique and believe that it is invalid. For instance, reader DennisW recently opined that “The ISAT data cannot, by itself, be used to determine a flight path. One has to invoke additional constraints to derive a terminus.” But I believe that the DSTG position is correct, and that one does not need to invoke arbitrary additional assumptions in order to calculate the plane’s track. I’ll explain why.

Continue reading How We Know Where MH370 Went

By MPat

(Note: A comment by reader Lauren H brought my attention to an analysis I’d overlooked by reader MPat. As Lauren H points out, it’s as timely now as it was when MPat first aired it back in March. — JW)

The potential arrival of more debris in the East African region is triggering interest once more in the currents and drift patterns in the SIO. To sense check the concept that debris could drift from the current search area to these regions I did a little research of my own, the premise being that the observed behaviour of real floating objects (and I am considering of course the buoys of the Global Drifter Program) should be a useful indicator of possible drift pathways, as a counterpoint to cell-based drift simulation models (which may be calibrated to high level drifter behaviour but typically lack the resolution to reproduce drifter movement in detail).

The full drifter database contains meta-data and trajectories for almost 19800 buoys worldwide (some 1400 are currently active). The meta-data includes timing of drogue loss, and a ‘death’ code to categorise the end of life status of buoys that cease transmitting. It is clear from this that drogues are typically lost in a surprisingly short timeframe. It is also notable that only 20% of all the buoys have ended their lives by running aground, with 66% simply ceasing transmission for undocumented reasons.

I have filtered out buoys that have at any time in their lives passed through the locality of the current search zone, based on a rectangle bounded by longitudes 88 to 96 degrees and latitudes -32 to -39 degrees. None were present in this area at the time of the crash, but I consider in any case all buoys that have ever been in this location (dates range from 1995 to 2014). There are 177 in this category. Of these, 39 are listed as having subsequently run aground. The locations at which they washed up are shown in the plot above.

Of the 39, 31 beached on East African coastlines, only 7 in Western Australia, and 1 in Sumatra. An example of 3 randomly chosen trajectories from the 31 that drifted west are shown below together with the box defining search locality :

The average time for buoys to reach their western beaching point after leaving the search box is 534 days (~ 18 months) with minimum 234 days (~ 8 months) and maximum 1263 days (~ 42 months). All but 3 were un-drogued during this journey, and those 3 lost their drogues en-route. For those arriving in Western Australia, the average time to beach was 362 days, with minimum 79 days and maximum 513 days.

If we relax the criterion that the buoys must end by running aground, and simply look at the locations where they eventually stopped transmitting after leaving the search area, we see the following three plots which display the 54 buoys that ended up west of longitude 55 deg (the longitude of Reunion Island),

the 12 that ended east of longitude 109 deg (coast of Western Australia),

and the 111 that remained in between:

Clearly the transport qualities of the ocean currents and weather systems will vary from month to month and year to year. It is also not clear how representative the buoys would be of the drift characteristics of floating debris resulting from a crashed aircraft. Neverthless I believe it is reasonable to propose from the buoy behaviour noted above across a 20 year drifting history that :

i) there is a strong tendency for objects that have been present in the current search area to remain trapped in the mid ocean gyre over extended periods

ii) a proportion, perhaps as high as 10% of robustly floating debris, might be expected to make landfall within 18 months of the crash

iii) the vast majority of the debris making landfall is likely to do so across the coastlines and islands of eastern Africa, with relatively little beaching in Australia.

For what it is worth, I have more background and analysis in a write-up that I hope to post soon.

Please also note that a vastly more expert analysis of drifter behaviour has been performed in October last year by David Griffin of CSIRO, in which he uses composite drifter trajectories to infer a likelihood function for where the MH370 flaperon may have originated. This is well worth a read.

UPDATE 79/2016: Reader Richard Cole has posted a link to a .kml file that shows the trajectories of the drifters that reached Australia. Here’s a screenshot of what it looks like if you drop the file into Google Earth. Interesting to note that the greater part of the debris winds up on the southern coast and Tasmania rather than the western coast.

Brock McEwen has released a new reverse-drift analysis of the MH370 debris that has been found in the western Indian Ocean. The executive summary is below.

Broadly speaking, Brock’s new paper supports the conclusion of his earlier work on the subject, and also parallels the findings of GEOMAR and Météo France, as I’ve written about earlier–namely, that reverse drift analysis suggests that the debris did not originate within the current search zone.

In conducting his analysis, Brock has erroneously included objects found in the Maldives which did not come from MH370, but my understanding is that the inclusion of this bad data did not materially change his results.

The Australian is reporting that “Despite finishing his term as the head of the ATSB without finding MH370, [Martin] Dolan said he remained hopeful the aircraft would be found” and believes the search should continue. The full story is behind a paywall but Amanda Rose has provided a screenshot here. Also of interest in the article is the assertion that, due to bad weather, the search might stretch on through October.

Meanwhile the New Straits Times says that “The ministerial tripartite meeting on the Malaysia Airlines Flight MH370 will be held on July 19, Transport Minister Datuk Seri Liow Tiong Lai said Friday… Liow reportedly said that the meeting would deliberate on the next course of action regarding the search for the aircraft, which went off radar on March 8, 2014, with 239 people on board while on its way from Kuala Lumpur to Beijing.” China, Malaysia and Australia have long said that the search will end after the current 120,000 sq km search area has been scanned, but some observers hold out hope that the rash of recent debris finds will encourage officials to press on.