Do you know that there’s a Soviet aircraft that actually couldn’t attack? The Soviet-made Ilyushin Il-40 is a post-World War II-around attack plane that has a unique double-barrel look. What’s also unique about it is that it couldn’t use the weaponry it had.
An Aircraft Desperately Needed
The story of this double-barrel shotgun with wings starts in the early 1950s when the Soviet arsenal of ground attack aircraft was severely lacking behind.
Their current stable of ground attack planes is consistent with any remaining Il-2 aircraft introduced in 1941 and the Il-10 introduced in 1944. These planes while very good at their time, couldn’t hold a candle to the modern jet planes. Thus, an upgrade was desperately needed.
Design Features
Powered by two McCool two Mikulin AM-5 axial-flow turbojets located on either side of the fuselage at the wing roots, the general design of the Il-40 was similar to that of a high-speed dive bomber. Combining the offensive and defensive weaponry you’d usually see on dive bombers with design advancements seen on jet fighters.
It would feature swept wings that are relatively common for jet aircraft with added wing fences to counteract wingtip stalling.
Issues
During the initial tests, it was discovered that after firing the guns, the plane started to slow down. It was also discovered that the engine actually flamed out and wasn’t working properly.
If this ended up being a common occurrence, then the Il-40 was effectively an attack aircraft that couldn’t attack lest the engines be disabled. Round tests of the gun showed that the issue wasn’t a simple anomaly but would happen anytime when the guns were fired. The expelled gas from the guns would be sucked into the engine air intakes which causes them to sputter and flame out.
To fix this, the guns were reworked and slightly improved in the process. The guns were removed and installed at the very tip of the nose and blast deflectors were installed that in theory, would keep any expelled gases away from the engine air intakes.
Pretty Solid Arsenal
Overall, the Il-49 had a pretty solid plane. During flight testing in early 1954, the flight was handled quite well compared to the Il-10. It was quicker, had a better rate of climb, and had more firepower and stronger weaponry. The Il-40 simply outclassed the Il-10.
Il-40 P
While it wasn’t as bad as before, the whole gun engine issue actually remained. The issue only appeared when the guns were firing when the plane was in a side slip.
To remedy this, the new Il-40P was introduced with the engine air intakes now at the very front of the plane, the gun was moved under the fuselage behind the front wheel. Thus, the gas from the guns couldn’t possibly be taken into the engine air intake so the issue was solved.
Engines were upgraded to the RD9V which brought a top speed of up to 600 017 miles per hour, and the bomb load increased to around 3,100 pounds of 1,400 kilos.
Cancellation
There were orders for 40 Il-40s in April 1956 but after just 5 of the 40 were made, production was ceased, and the program was abruptly canceled.
However, this cancellation had nothing to do with the Il-40 but more to do with a change in Soviet military doctrine as a whole. Instead, they decided to use nuclear weaponry to fulfill these roles during the Cold War, where nukes were in vogue.