SITA has confirmed it supplies Malaysia Airlines with communications via VHF radio and Inmarsat satellites for its fleet’s Aircraft Communications Addressing & Reporting System (ACARS) avionics, and that it is assisting authorities in the probe of what happened to Flight MH370.

“The Malaysia Airlines ACARS avionics communications via the SITA network is proprietary to the airline. We are fully supporting the airline and all the relevant authorities in their on-going investigation of flight MH370,” says a SITA spokeswoman, declining further comment.

Earlier this week, Inmarsat president, aviation Miranda Mills revealed that the satellite provider was supporting the investigation, “as part of the service we provide” but could not comment further at that time. Runway Girl Network tweeted Mills’ comments from the Satellite 2014 conference in Washington DC. “We want to extend our sympathies to the families of the people involved,” added Mills.

But in a statement released today, Inmarsat said routine, automated signals were registered from MH370 during the flight from Kuala Lumpur, and that this information was shared with SITA, “which in turn has shared it with Malaysia Airlines”.

Inmarsat’s Classic aero service underpins the ACARS messaging via satellite that SITA provides. So just what type of information might SITA have at its disposal? Runway Girl Network reached out to an industry insider and expert for answers.

Even on narrowband Classic aero service, he says, “you have a GPS fix from the instruments because the satellite terminal needs to know where it is, and what satellite it needs to connect to. The terminal is pinging satellites, and if the satcom is switched on it is trying to connect to the satellite. The service provider [in this case SITA] is verifying it’s a valid terminal and then you have your connection.

“As long as you have air-to-ground coverage, ACARS messages are delivered via ground, but once you leave land and you’re over water, it has to be satellite, there is no other option. If you’re connected, it would probably provide positioning data, yet when references are made to ‘pinging’ it sounds like the terminal is trying to get onto the network but can’t register.

“If the satcom was alive for hours, that means the aircraft was alive. For reference, Air France AF447 continued to work even as the aircraft was at the point of breaking up or hitting the water. Once the unit hits the water and loses power, it’s gone. Inmarsat’s higher bandwidth SwiftBroadband service pings positioning of aircraft. With Classic aero, you don’t have the same granularity, but with timings you’d look at the last known [ping] point and look at the circle and go from there.”