The search to find out what happened to the MH370 flight began in earnest. As days ticked on by, it became apparent there would be no happy ending and that those on board were lost. However, with the families of those involved wanting closure and the international community wanting explanations, there has been a huge intensity to the search, which so far has yielded no physical evidence.
Inmarsat, the Mobile Satellite Services (MSS) operator, was in the eye of the storm, and became a key contributor in the international search for the missing aircraft. Mark Dickinson, vice president of satellite operations at Inmarsat, outlines the role he and his team played in support of the international investigation in what continues to be one of the biggest global hunts of recent times.
Initial press reports suggested that the aircraft might have gone down in the South China Sea, but thanks to satellite technology, authorities turned to the southern part of the Indian Ocean, west of Australia. It is here that the international search for the aircraft continues to this day.
It was due to technology improvements and upgrades to its ground network — which Inmarsat undertook in 2013 — that sufficient data from MH370 was available to guide the international search team; a few numbers could make a huge difference.
“If it wasn’t for the [Burst Timing Offset] BTO and [Burst Frequency Offset] BFO numbers, that appear in the [Ground Earth Station] GES signaling logs [in Perth], no positional information would have been able to be determined and the search area would be 100 million square kilometers,” says Dickinson.
3,000 Media Requests
At its peak, Inmarsat received 3,000 media requests in four days — an unheard of amount for a satellite operator — and the media scrum that materialized outside Inmarsat’s headquarters in Old Street, London in late March, showed the hunger for information related to MH370. Like most people, Dickinson heard of what happened on Saturday, March 18 and he admits he had no idea at the outset how this would impact him, his team and Inmarsat. It had just been a normal Saturday before then.
Things moved fast. During the week immediately following the disappearance of MH370, Dickinson says things “started to register.” Inmarsat had information in its logs that it believed could prove useful. The company was quick to engage with the investigators and to explain what this data was saying about the likely flight path.
“We had engineering logs from our Perth ground station relating to the missing plane. What this told us was that the Inmarsat terminal on-board the flight had continued to operate for many hours after the contact was lost when the aircraft left Malaysian airspace,” he says
The fact that this data was available was thanks to additional storage capacity Inmarsat had incorporated during its ground network upgrade in 2013. This, in turn, was a direct result of the company’s involvement in the search for Air France 447 flight in 2009, where 229 people lost their lives. While Inmarsat was not directly involved in this investigation, the company took steps to store more data fields with the thought that this information could prove valuable in the future.
“We added the BTO values to the GES logs that we stored following our experience with AF447. When we took this decision, we did not know precisely how it might be useful but we had a hunch and decided to make the investment. So we went through an upgrade process on our software for all of our ground stations so that we could record this information. This rolled out in Perth last year,” Dickinson says. “If it wasn’t for that upgrade, we would not have had the relevant data and hence the range rings that we, and the international investigation team, were able to construct.”
Map of known flight path followed by Malaysia Airlines Flight 370
A key reason this data proved so valuable is due to the manner in which Inmarsat flies its satellites in the latter stages of their life. For certain spectra, maintaining a geostationery satellite in a precise position relative to the Earth is essential. Fortunately for Inmarsat’s L-band services, this degree of precision is not essential in terms of the speed or reliability of the voice and data connection provided to a user at sea, on land or in the air. Due this “pointing tolerance,” Inmarsat is able to extend the life of its L-band satellites by using less fuel for station keeping. In essence, this means that its engineers allow older satellites to range North and South as the spacecraft orbits with the Earth.
Inmarsat’s 3F1 satellite was nearly 18 years old in March. The company is able to operate this satellite in an inclined orbit later in life, which means the satellite now no longer appears fixed in the sky but moves mainly in a north-south motion over a 24-hour period. “When the terminal on an aircraft attempts to correct for the Doppler motion, it doesn’t do this 100 percent correctly because it doesn’t know about satellite’s relative motion and that the satellite isn’t quite were it is expects it to be. Using this discrepancy is central to determining if the aircraft flew north or south,” Dickinson says. “If you stand in the Southern hemisphere and observe an object in an orbit moving from North to South it will appear that it is moving towards you, and the Doppler effect would mean the frequency would increase, just like the sound a train makes when it is coming toward you. With the known motion of the satellite, we were trying to determine the relative position and motion of the terminal to match the data recorded in the logs. We obviously had to validate the technique against over aircraft in the air at the same time using both the same satellite and ground station. It was this technique that allowed the northerly potential route to be ruled out. Subsequently, the investigation team refined this technique and validated this against many other known flights.”
To put into context how important these numbers are, thanks to Inmarsat and the work performed by the investigation team led by the Australian Transport Safety Bureau (ATSB), the area being searched for MH370 is 60,000 square kilometers. Without the data, the search area could be, in theory, 100 million square kilometers. While this does not necessarily mean that physical evidence for the fate of MH370 will be found, it certainly narrows the odds.
“All the available data points to a location in the Southern Indian Ocean. The analysis techniques have been refined and extensively validated. The search area is determined by the region of the highest probability. The work of the investigation team has been to determine this probability distribution in order to optimize the search effort. However, it cannot provide an ‘X marks the spot’ type of solution,” admits Dickinson.
The First Week
In those crucial first days after March 18, Dickinson admits that Inmarsat realized it had some really important information. Inmarsat’s engineers had seen something that had deserved investigation and decided to take a much closer look. It was in the next couple of days when they were able to connect some of the dots and apply a “bootstrapping” approach to the BTO values and come up with the northern and southern routes.
What was critical about Inmarsat’s information was that it countered the general view of where the aircraft might actually be and that, in fact, MH370 had been flying a lot longer than people had initially thought.
“It is common sense to begin a search from the position of the last confirmed contact. The data from the terminal we had was indicating that the aircraft was flying far longer than originally realized and that its flight path was far removed from the initial search area,” Dickinson says admitting there was quickly a realization that the information they had was potentially very important. “In such circumstances, you go into a mode where you try and ignore what is going on externally and just focus on examining and analyzing the data. If you look at what was going on externally, you have the potential to be somewhat blinded by it and be a rabbit in headlights.”
Dickinson talks of a very focused approach and, above all else, ensuring that the data was correct. He says there was a lot of double and triple checking at the time. “We had to do more than just connect the dots; we understood the potential of what this meant. We had to brief the search professionals about it — an investigation of this sort is not our natural field,” he says.
Inmarsat’s satellites were telling a story. “Other than the radar information, we essentially just have some signaling information which is keeping the network between the terminal on the aircraft and ground station active. There isn’t any communications happening as such. This is simply the network saying to the terminal, you haven’t responded to me, are you still there?” Dickinson says.
The Second Part of the Week
From the initial BTO analysis during the first week, things moved on at pace when Inmarsat engineers started to decipher further key elements of the data. “The work was ongoing in terms of analyzing this frequency information. There were steps forward, steps backward. During the second week, we made some strides forward which enabled us to understand the importance of these numbers and allow us to determine the potential direction of travel and the approximate region of the last signal our satellite received,” says Dickinson.
He remembers standing in the lobby of Inmarsat after the announcement was made by the Malaysian Prime Minister and the TV crews started to show up. “We realized what it meant. What had been foremost in our mind was the human dimension of those missing and their families,” he says.
But, Dickinson admits there is only so much him and his team can do, as the technology has certain limits. Although a region can be defined, it doesn’t provide a GPS-like position. “The investigation team had been calibrating the data, validating it against other aircraft,” he says. “This is just a communications terminal. It wasn’t designed to provide navigation information. We were trying to use the signaling information from a communication system and turn it into a navigation device.”
As Inmarsat put all its resources at the disposal of the international investigation team to try and narrow the search area, personal tragedy struck Dickinson and his team. Dickinson and a colleague flew to Kuala Lumpur to brief the investigation team at the end of the first week. On the way back, Dickinson was meant to fly from Kuala Lumpur to Los Angeles via Heathrow early in the second week. As he landed at Heathrow, he found out that a key member of his operations team, one of the satellite controllers, had suddenly died overnight. The team was already working overtime and being such a closely-knit group, the tragedy hit them hard. Dickinson abandoned his plans to go to Los Angeles and went back to work. He reflects back saying it was an “unusual and sad time.” It was a trying time for all those involved.
Almost nine months have passed and the mystery of what happened to Malaysia Airlines flight 370 remains unsolved — and there is a chance it may never be solved. Inmarsat is involved in regular calls with the investigation team. The underwater search continues and there is a feeling of “cautious optimism” that the plane will be found.
“The search area is large and this is a result of the many uncertainties and accuracy of the measurements. It is a big area and searching anything at the depths involved is a challenge,” says Dickinson.
For all those involved in the process of analyzing this information, the search has left an indelible mark. It will also focus the satellite industry’s efforts on providing the technology that, hopefully, will mean aircraft won’t go missing in such a way again.
“There are new technologies and systems that will come online, and satellites will always have a very important part to play in that. The world of aviation communication is going to change over the next 10 years; we will see far more communication throughout the aircraft for both crew and passengers. And no more important aspect is the role of communications in delivering the highest standards of safety. Most wide-body aircraft already carry an Inmarsat terminal and we have submitted our suggestions to the industry on how to enhance reporting functions,” says Dickinson.
While helping with the ongoing investigation and hoping for a satisfactory outcome, Inmarsat’s work, in many ways, is done. The surge of interest in the company is now over; the media requests have dwindled. But, for a few select members of Dickinson’s team, it was an experience quite unlike any other. And if the MH370 is ever found, a few satellite engineers who go about their daily jobs with precision and daily excellence will have played a key role. Working long hours and overcoming the loss of a key team member, they worked to help provide answers from the data.
“Certainly, for a small number of individuals [at Inmarsat], it involved quite a lot of work. We have been trying to do what is right and helping the investigation team. We have a lot of good engineers who understand the systems involved and by helping the investigation team, we’ve been trying to make sure we’ve understood the data as best as we can. All we have is just a small handful of numbers from an engineering log file,” Dickinson says.
Mark Holmes is the editorial director for Avionics Magazine and Via Satellite.