Trials are starting in order to see if unmanned flights could be flown in British airspace.
If successful, the trials could lead to pilotless aircraft being used for such tasks as search-and-rescue operations and for detecting volcanic ash cloud.
Ultimately, the trials could even result in passenger flights being flown in unmanned planes although it could be many years before that happens.
The trials are being conducted by aerospace company BAE Systems using a BAE Jetstream aircraft.
A pilot and a co-pilot are being used for the take-off and landing of the test flights but once the aircraft is airborne a computer takes over.
Equipped with systems far more sophisticated than those on modern passenger planes, the Jetstream plane can avoid collisions with other aircraft, detect and avoid bad weather conditions and can work out a safe place to land in the event of an emergency.
BAE and a series of companies backing the project hope that the trial will demonstrate to regulators such as the Civil Aviation Authority and air traffic control service providers the progress made towards achieving the safe use of what are known as UAV (uninhabited air vehicles) in UK airspace.
BAE Systems spokesman Simon Shrouder said: "Everyone has to be satisfied that this plane can fly safely and land safely.
"Once confidence in the aircraft grows, it could be used for such things as coastal patrols, search-and-rescue missions and checking out possible volcanic ash clouds."
He went on: "In years to come, it might be that confidence is so great that there is scope for passengers to be carried on these flights - but that's many, many years off.
"It might be argued that passenger planes practically fly themselves already, but this Jetstream that's being tested is much more sophisticated than anything being flown at the moment."