Malfunction safety mechanism

[Styx75]

Mr Soward said it was unlikely because the plane was fitted with a safety mechanism that would have slowed its speed down to 40 knots if there was a fault.

From this link: Qantas pilot Paul Whyte, feared dead in Byron Bay plane crash, hit water at 200km/h (http://www.smh.com.au/nsw/qantas-pilot-paul-whyte-feared-dead-in-byron-bay-plane-crash-hit-water-at-200kmh-20160323-gnq1u4.html)

Keeping this separate from the key topic of the article (discussed in another thread), does anyone know of such a device Mr Soward is referring too?

[Styx75]

Looks like SMH have edited that part already. Now reads:

Asked if a plane malfunction could have occurred, Mr Soward said it was unlikely because the plane would have slowed its speed if there was a fault.