The crash took place at 10.40 am Moscow time on Tuesday
[07.40 GMT], three kilometers from the village of Praskovye
in the Budyennovsk district.
"According to preliminary information, the engine
gearbox broke and the crew decided to carry out an emergency
landing," the source said. "The aircraft crashed
cabin-first into the ground."
The injured crew members, one of whom was knocked out
in the crash, were hospitalized.
The Mi-28N Night Hunter is an attack helicopter, optimized
for destroying armored vehicles and slow-flying aerial
targets. The aircraft is robustly built and can withstand
crashes involving a high vertical rate of descent.