When a tragedy like the Germanwings crash hits, we all start looking for ways to prevent it from repeating.
One proposal is planes that can be controlled from the ground.
One plane over England has a crew at the controls and passengers in the back, but something extraordinary is about to happen.
A pilot on the ground is taking over.
The $94 million Astraea project by the British aerospace company BAE was one of several efforts around the world to develop planes that can be flown remotely.
"And what you're hearing right now is discussion with air traffic control that is exactly the same as what the pilots would be having if they were in charge of the steering of the aircraft," said BAE Systems Test Engineer Duncan Casey.
Military success with drones has driven much of the interest, and some efforts are focused on airplanes in hazardous conditions, such as hurricane research and fighting wildfires.
Analysts say pilotless planes could be a $400 billion a year global business.
So why not passenger flights?
First, the airline industry has a remarkable safety record despite high-profile disasters. Many believe onboard pilots remain the most reliable way to handle problems, and retrofitting planes would cost billions of dollars.
Second, passengers may not be ready.
"I start by asking myself that question -- how would I feel getting into an airliner that didn't have airline pilots up front? And I wouldn't do it," said Flying Magazine Editor-in-Chief Robert Goyer.
There are unanswered questions about reliability. For example, if a plane is being controlled from the ground, what if the control station loses contact or if terrorists strike?
There could be a redundant system that required two or more stations to control any plane at any time that might address those concerns.