[hughes]

Why is it that we can track boats with satellites but not planes? In fact we have a complete image[1] of boat activity in the area at the time of disappearance.

It seems as crazy to me as how we can offer in-flight satellite-based wifi but not GPS tracking.

[1] http://i.imgur.com/XYvC5gI.jpg

[dingaling]

> Why is it that we can track boats with satellites but not planes?

Satellites don't track either ships or aircraft, except for huge nuclear-powered RORSATs that watch the fleets of rival superpowers.

However whilst many trans-oceanic aircraft do have VHF / UHF datalink uplinks through the Inmarsat satellite network the majority use line-of-sight UHF transponders ( beacon-tracking ) to supplement radar ( skin-tracking ):

https://fr24.com/2016-05-19/00:28/12x/MSR804/9c0b766

Transponder interrogation is often referred to as "secondary radar" but that's a misnomer that unfortunately took hold in the industry. It relies on 'squitting' a generated response, not on reflections from the aircraft structure.

[Neil44]

Boats are tracked by their AIS beacons on board, not passively by radar. The beacons can be switched off or stop working just the same as the beacons on planes.

[gchadwick]

The article says it disappears from radar. When tracking aeroplanes there are two kinds of radar primary and secondary. Primary is actual radar, secondary isn't really radar at all but instead radio transmission of telemetry such as position, altitude, speed etc. This is equivalent to AIS, the system used to track boats that produced your image.

So we were tracking the plane but then the plane stopped transmitting tracking info for some reason (no idea if they even had it on primary radar). Someone could have turned it off or the plane could have crashed.

[brador]

There is no need for a pilot to be able to disable tracking on a commercial plane.

They should position the tracking hardware outside the plane making it relatively tamper-proof mid flight.

[tonylemesmer]

Unless its on fire? Isn't that always the reason for having all the kill switches on aircraft?

[cm2187]

Like another commentor here I don't have a huge amount of trust in early media reports but what I read was that it was within radar range when it disapeared.

[kevinnk]

Those boats are presumably sending a signal that allows them to be tracked. When we "lose" a plane, it stops sending its tracking signal.

[kalleboo]

You have a complete image of flight activity in the area as well (see flightradar24). No doubt the plane crashed.

[kyriakos]

lets also not forget that there is a substantial presence of military fleets in the area, all equipped with radars etc if it was anything other than a crash they'd have noticed.