A simple computer upgrade that Malaysia Airlines decided not to purchase would have provided critical information to help find the airliner that disappeared 11 days ago.
The upgrade, which wholesales for about $US10 per flight ($10.90), would have provided investigators with the direction, speed and altitude of Malaysia Airlines Flight MH370 even after other communications from the plane went dark, said a satellite industry official familiar with the equipment.
The unexplained fate of Malaysia Airlines flight MH370 has thrown the spotlight on satellite technologies. Photo: Reuters
Data from a similar computer upgrade allowed investigators in the 2009 crash of an Air France jet liner to quickly narrow their search area to a radius of about 64 kilometres in the Atlantic Ocean, and in five days they found floating evidence of the crash.
The ocean search for the missing Malaysian flight now covers a massive expanse of water, about 3.36 million square kilometres (2.24 million square miles) of the Indian Ocean from the west coast of Malaysia to the waters off Perth, Australia.
"We've got to hope for a break," said Dave Gallo, who directed the search by the Woods Hole Oceanographic Institution that found the Air France plane. "Someone's got to find on the surface some bit of that plane floating."
The story of the missing Malaysian plane, with 229 passengers and crew on board, has drawn the public into the arcane nuances of communications between aircraft and ground bases.
The new information indicates that had the upgrade for a system called Swift been installed, it would have continued to send flight data by satellite even after the plane's transponder and Aircraft Communications Addressing and Reporting System (ACARS) communications went dead.
Investigators say they think those two systems were shut down by a pilot or hijackers in the cockpit before the plane flew on for another seven hours.
The satellite industry official, who spoke on the condition of anonymity because of the sensitivity of the investigation, likened the Swift system to a mobile phone that sends data to a satellite. He described ACARS as akin to an app for a mobile phone.
Had the Swift system been upgraded to include the full package of applications, it could have sent information on engine performance, fuel consumption, speed, altitude and direction, regardless of whether the transponder and ACARS were working, he said.
"When ACARS is turned off, Swift continues on," he said. "If you configure Swift to track engine data, that data will be streamed off the plane. It continues to be powered up while the aircraft is powered up."
Many major airlines use the full package of Swift options. The detail it provides is mandated under international aviation guidelines for airlines that fly the busy North Atlantic corridor between the United States and Europe. There are no such requirements elsewhere in the world, the industry official said.
In addition to sending information to the airline, Swift also can be programmed to send data to the manufacturer - usually Boeing or Airbus - and the engine maker - usually Rolls Royce or Pratt & Whitney.
"It's a choice of what you do with your aircraft," the satellite industry official said. "When you get your plane from Boeing, you can get an engine management app, a route management app, or you might decide that you want the bare minimum. There isn't a mandated requirement."
The application wholesales for about $US10 per flight, but airlines pay a higher retail fee. Some airlines have decided they do not want to pay the higher cost for an information stream that they deem unnecessary except under the most extreme circumstances.
Zainul Zawawi, vice president for North America operations at Malaysia Airlines, said he was not authorised to speak about the missing flight and referred questions to airline officials in Malaysia. Efforts to reach those officials were not successful.
Asked why an airline might choose not to buy an application that sells for a relatively modest cost, the official said, "Every pound on an aircraft is fuel consumed. As in all matters, it always comes down to cost."
Rather than stream that data, he said, some airlines choose to download it onto a USB stick once the plane lands.
Because Malaysia Airlines went with the cheaper option, he said, "there was not an awful lot that was captured."
With the transponder and ACARS not operating, the satellite tried to contact the missing flight hourly.
He said the satellite "sends out an automated ping to say, 'Are you there?' and the machine-to-machine response is, 'Yes, I am.' "
That "yes, I am" response is how investigators determined that the plane flew on for several hours.
"On the Air France flight, they used the satellite network to bring the [additional] information off and narrow the search," he said.
With all the on-board systems working - the transponder, ACARS and Swift with all available applications - the search for Air France 447 narrowed quickly.
"We had a last-known position, and we knew that after the last-known position there were four bursts of ACARS transmissions, and then they stopped abruptly," Mr Gallo said. "So the decision was made that the plane was down four minutes after the initial event."
Once debris was found, investigators had to calculate how far it had drifted in the five days since the plane crash.
"We thought five days was a long time for that tracking," Mr Gallo said, reflecting on the fact that it has been 11 days since the Malaysian flight disappeared.
It took almost two years - from June 2009 to May 2011 - before the wreckage of the Air France flight was found on a plateau more than 3352 metres deep in the Atlantic off the coast of Brazil. With no hint of where the Malaysian plane might have gone down, Mr Gallo said that perhaps the only hope it will be found rests on the discovery of some floating debris.
"It's a big chunk of the Indian Ocean, almost the size of the North Atlantic," Mr Gallo said. "If [the plane] is in the ocean, it can range from the flat sediments of the Bay of Bengal, two miles plus deep, and the further south you get, west of Perth is one of the most incredibly complicated underwater terrains on the planet."
Julie Tate, Alice Crites, and Jessica Schulberg contributed to this report.