Video report from ITV News Correspondent Dan Rivers
ITV News went up into the air to see how easy it would be for a plane to disappear off the radar after Malaysian authorities said they are focusing on the theory that a "deliberate" action was behind the disappearance of flight MH370.
Dan Rivers travelled in a light aircraft 5,000 feet above Hampshire to see how easy it would be for a Boeing 777 to vanish from a radar.
In a pre-arranged demonstration with Air Traffic Control, Pilot Robin Durie turned off the plane's transponder which left the aircraft anonymous on radars.
– Robin Durie, Pilot
It is as simple as pressing a button and should mean we've disappeared from the radar screen and, in this case, a military radar screen.
And then I turned [the button] back on again and now we're back visual again.
It's as simple as that.
If a pilot turned off the transponder, descended and then hid behind high ground, the aircraft would completely vanish from radars.
However, a former RAF Tornado pilot told ITV News that although this was possible for an experienced pilot to perform, it would be a manoeuvre fraught with problems.
– Jake Waterson, Former RAF Tornado pilot
Your fuel burns so much more which reduces your range and also if you were planning to fly to a country with mountainous terrain, you'd have to start avoiding the hills.
Also, at those heights you become very visible to people on the ground.