The Soviet Yak-9DD fighter with the VK-105PF engine is a version of the long-range fighter, a modification of the Yak-9D and Yak-9T.
The number of fuel tanks has been increased, the design of the wing has been changed, equipment has been installed for flights at night and in difficult weather conditions. The modification of the Yak-9DD was carried out by the Design Bureau in connection with the necessity in 1944 to have a fighter with a greater flight range than in the Yakovlev Yak-9D, capable of performing the tasks of escorting bombers during their actions along the enemy’s deep rear.