The Avro York was, like its Lancaster and Lincoln stablemates, a versatile aircraft.
One of the prototypes, LV633, Ascalon, was custom-built as the personal transport and flying conference room for Prime Minister Winston Churchill.
Ascalon was to be fitted with a special pressurised "egg" so that VIP passengers could be carried without their having to use an oxygen mask.
Made of aluminium alloy, the enclosure had eight perspex windows to reduce claustrophobia.
It also had a telephone, an instrument panel, drinking facilities and an ashtray with room for cigars, a thermos flask, newspapers and books.
Testing at RAE Farnborough found the "egg" to work satisfactorily.
Avro said it was too busy with the new Lancaster IV (Avro Lincoln) work so it was never installed in Ascalon.
It was considered for installation in the successor aircraft, a Douglas C-54B but the contractor Armstrong Whitworth decided it was impractical and the project was shelved.
The whereabouts of "Churchill's Egg" is not known.

MW140, Endeavour, flew to Australia in 1945 to become the personal aircraft of the Duke of Gloucester, Australia's Governor-General.
It was operated by the Governor-General's Flight from 1945 to 1947; it was the Royal Australian Air Force's only York.
Another York, MW102 was fitted out as a "flying office" for the use of the Viceroy of India and C-in-C South East Asia Command, Lord Mountbatten.
During its first major overhaul by Avro at Manchester (Ringway) in 1945, the aircraft was repainted a light duck egg green, a shade intended to cool down the aeroplane, instead of its former normal camouflage colour scheme.
South African leader Jan Smuts also used a York as his personal transport.
Air Chief Marshal Sir Trafford Leigh-Mallory was killed on 14 November 1944, while flying to his new posting in Ceylon to take command of Allied air operations in the Pacific, when York MW126 struck a ridge in the French Alps in a blizzard, 30 miles (48 km) south of Grenoble, France.
His wife Dora and eight aircrew also died.
The wreckage was found by a villager in June 1945.
The Avro York was, like its Lancaster and Lincoln stablemates, a versatile aircraft. One of the prototypes, LV633, Ascalon, was custom-built as the personal transport and flying conference room for Prime Minister Winston Churchill. Ascalon was to be fitted with a special pressurised "egg" so that VIP passengers could be carried without their having to use an oxygen mask. Made of aluminium alloy, the enclosure had eight perspex windows to reduce claustrophobia. It also had a telephone, an instrument panel, drinking facilities and an ashtray with room for cigars, a thermos flask, newspapers and books. Testing at RAE Farnborough found the "egg" to work satisfactorily. Avro said it was too busy with the new Lancaster IV (Avro Lincoln) work so it was never installed in Ascalon. It was considered for installation in the successor aircraft, a Douglas C-54B but the contractor Armstrong Whitworth decided it was impractical and the project was shelved. The whereabouts of "Churchill's Egg" is not known.
MW140, Endeavour, flew to Australia in 1945 to become the personal aircraft of the Duke of Gloucester, Australia's Governor-General. It was operated by the Governor-General's Flight from 1945 to 1947; it was the Royal Australian Air Force's only York. Another York, MW102 was fitted out as a "flying office" for the use of the Viceroy of India and C-in-C South East Asia Command, Lord Mountbatten. During its first major overhaul by Avro at Manchester (Ringway) in 1945, the aircraft was repainted a light duck egg green, a shade intended to cool down the aeroplane, instead of its former normal camouflage colour scheme. South African leader Jan Smuts also used a York as his personal transport. Air Chief Marshal Sir Trafford Leigh-Mallory was killed on 14 November 1944, while flying to his new posting in Ceylon to take command of Allied air operations in the Pacific, when York MW126 struck a ridge in the French Alps in a blizzard, 30 miles (48 km) south of Grenoble, France. His wife Dora and eight aircrew also died. The wreckage was found by a villager in June 1945.
Avro York