Helicopter manufacturer studies diesel-cycle engine to power proposed six-seat variant, which may join R-22 and R-44

Robinson Helicopter is considering an expansion of its two-model light helicopter family, with the launch of a six-seat variant, which could be powered by a diesel-cycle engine.

The US helicopter manufacturer builds the two-seat R-22 and larger R-44, which accommodates up to four people. Company president Frank Robinson says there are "several studies under way" for a six-place helicopter, dubbed the R-66, but that "the big question is: piston or turbines?"

Robinson says any six-seat airframe would require a powerplant of 350-400hp (260-300kW), and each option has its disadvantages. "Pistons get too hot at that power and turbines are too heavy," says Robinson. His "favourite option" would be a diesel engine, once manufacturers have perfected the technology. "We have a number of designs and engine options we are working on, but nothing to get excited about yet," he adds.

Meanwhile, Robinson says he has ruled out much growth potential for the missionised versions of R-44 Raven variant in Europe until rules on single-engined operation are changed.

Robinson sold its first R-44 ENG Newscopter fitted with electronic newsgathering equipment in the UK last week, and has held preliminary talks with several metropolitan police forces in Europe about using the R-44 Police variant in auxiliary roles.

Outside Europe, "we expect to see strong sales of the R-44 Police as local governments seek ways to reduce their law enforcement spending," he says.

Robinson says the company has recovered the development cost of the three-place helicopter, which features forward-looking infrared sensors, searchlight and observation doors, following the tenth order. Estonia is the only European country to operate the R-44 Police.

Source: Flight International