High - altitude interceptors

In July of 1940, one Junkers Ju 86P-2 of the Aufklärungsgruppe Ob.d.L was overflying Britain at 41,000 ft. with impunity, on a photographic sortie.
The best British interceptor Spitfire Mk. II had 37,000 ft. service ceiling and the best US interceptor, Republic YP-43, had 38,000 ft.
In November 1944 the armour of a Focke-Wulf Fw 190 Sturmböck weighed 256 kg and the pilots had to use the MW 50 power boost and doubling the fuel consumption rate to reach the flight altitude of the turbocharged American bombers.
During the last months of 1940, the Luftwaffe conducted clandestine reconnaissance sorties, deep into the Soviet airspace, operating with a mixture of Dornier Do 215 B-4, Dornier Do 217 A-0, Junkers Ju 86 P-2 and Junkers Ju 86 R-1 spy planes.
The MiG-3 was originally designed as a high-altitude interceptor but in real combat conditions some planes entered irrecoverable spins flying at 30,000 ft.
It was known that the B-29 could fly at high altitudes thanks to its turbocharged engines, but when it first appeared at 33,000 ft. above Tokyo, it was flying so fast that the Ki.44 interceptors of the 47th Sentai could not reach it.
The appearing of these sub-stratospheric planes forced the British, Germans, Russians, and Japanese to design and build 186 different types of high-altitude interceptors described in this book in 156 pages of drawings and 70,000 words.