Modern-Aviation

As part of a Stalin ‘inspired’ post-war rush to revive helicopter development, Yakovlev were ‘invited’ to design a heavy lift helicopter. The task seemed simple: make a boxy fuselage to put everything in and put a rotor at each end to lift it off the ground. As with most things helicopter-related, it turns out nothing is that simple.

Power was to be provided by the same Shvetsov Ash-82V engine, gearbox, and rotors as used in the Mi-4 Hare, except two of them. Presumably, due to sanity issues, one was placed just above the loading ramp, and the other was tilted over and squeezed behind the cockpit.

To stop the blades from clashing, a synchronisation shaft connected the two gearboxes and allowed power to be transferred front to rear, or vice versa, in the event of an engine failure. Outside of this list, this has not proved a popular configuration.

The first indication that everything may not be right with the Horse came during ground testing when the rear rotor vibrated itself and its gearbox free and committed seppuku by ripping the fuselage apart. Further trials revealed that behaving like a tumble dryer with a brick in it was a feature of the Yak-24 that it might be an idea to design it out.