That's the one SD
!
The Tupolev ANT-29 DIP (
Dvukhmotorny
Istrebitel
Pushechny, or twin-engined cannon fighter)
Actually it's the exhaust for the 102mm Kurchevski DRP, a recoilless gun of 4.00m length, discharged through a steel tube projecting from the rear of the fuselage beneath the rudder!
[quote-=] The project was abandoned after a loss of interest in Kurchevski's recoilless guns for which the ANT-29 had been designed. These had suffered repeated failures leading to Kurchevski's arrest and subsequent disappearance. [/quote]
Well, my challenge didn't fare much better then the gun's designer who fell foul of "Uncle Joe's" displeasure!
Sabredog has control 