The almost perfectly preserved Kittyhawk P-40 is an aviation time capsule that has remained unseen and untouched since it came down in the Sahara in June 1942.
It is thought the pilot survived the crash and initially used his parachute for shelter before making a desperate and futile attempt to reach civilisation by walking out of the desert.
The RAF airman, believed to have been Flight Sergeant Dennis Copping, 24, was never seen again.
The single-seater fighter plane was discovered by chance by Polish oil company worker Jakub Perka exploring a remote region of the Western Desert in Egypt.
The location is about 200 miles from the nearest town.
Most of its cockpit instruments are intact and it still had it guns and ammunition before they were seized by the Egyptian military for safety reasons.
There are also signs of the makeshift camp the pilot made alongside the fuselage.
No human remains have been found but it is thought the pilot's decomposed body may lay anywhere in a 20 mile radius of the plane.
The RAF Museum at Hendon, north London, has been made aware of the discovery and plans are under way to recover the aircraft and display it in the future.
A search will also be launched in the slim hope of finding the remains of the lost airman.
The defence attache at the British embassy in Cairo is due to visit the scene in the near future in order to officially confirm its discovery and serial number.
But there are fears over what will be left of it after locals began stripping parts and instruments from the cockpit for souvenirs and scrap.
Historians are urging the British government to step in sooner rather than later and have the scene declared as a war grave so it can be protected before the plane is recovered.
Andy Saunders, a military aviation historian, said: "The aviation historical world is hugely excited about this discovery.
"This plane has been lying in the same spot where it crashed 70 years ago. It hasn't been hidden or buried in the sand, it has just sat there.
"It is a quite incredible time capsule, the aviation equivalent of Tutankhamun's Tomb. It is hundreds of miles from anywhere and there is no reason why anyone would go there."
Mr Saunders said there was evidence the Ft Sgt Copping survived the crash as there evidence he used the plane for shelter and tried to restart it.
But inevitably he would have walked to his death.
"Once he had crashed there nobody was going to come and get him," he said.
"It is more likely he tried to walk out of the desert but ended up walking to his death. It is too hideous to contemplate."
Flt Sgt Copping was the son of a dentist and came from Southend, Essex.
In 1942 he was a member of the RAF's 260 Squadron, a fighter unit based in Egypt during the North Africa campaign.
By June of that year the Allies were retreating from 'Desert Fox' Erwin Rommel and his German forces.
On June 28 Ft Sgt Copping and another airman were tasked with flying two damaged Kittyhawk P-40 planes from one British airbase in northern Egypt to another for repair.
During the short flight Ft Sgt Copping lost his bearings, went off course and was never seen again.
Ft Sgt Copping's name appears on the El Alamein war memorial. It is not thought that there are any immediate family members of his left in the UK.
Captain Paul Collins, the British defence attache to Egypt, confirmed there will be a search carried out of the area around the plane in the hope of finding his remains.
The Kittyhawk was an American manufactured plane used by the RAF in its desert campaign.[The Telegraph]