Engine improvements
Just read the article over a coffee and noted the following comment.....
....the engines upgraded to the more powerful and fuel-efficient Pratt and Whitney PW210S. This burned about 600lb/h on our 8 December test flight. Sikorsky experimental test pilot Greg Barnes, in command for the test flight, says this is typical.
That’s about 50lb/hr less than the S-76C++ and with more fuel onboard, range should surely be increasing, not decreasing.
P&WC claim.....
″The PW210S has been designed to offer the highest power-to-weight ratio and lowest fuel burn in the market, which translates into payload and range benefits for the helicopter.″
Much as this could be construed as just sales bumf, P&WC has an excellent standing in the helicopter industry (take a look at the AIN Product Support Survey these past 10-years) and Pratt must have spent a small fortune these past 6-years’ or so on the PW210 engine, so I find it hard to believe their new generation PW210 series does not promise notable improvements in fuel burn, power, reliability and life cycle costs.
Platform size and output power aside, the PT6C-67C gas generator is a derivative of the PT6A-67 (as used on the Shorts 360-300 and Beech 1900D) and there can be no doubting the outstanding reputation of the venerable and reliable PT6 series, but its design is over 50-years’ old and getting a little long in the tooth if truth be told.
Whereas the PT6C-67C has a 5-stage compressor (yes it’s kicking out more mass flow), the PW210S has just 2 compressor stages and encompasses a VIGV, so technology improvements and lower life cycle costs - let alone huge fuel burn differences - must make the PW210S a much more economical engine to operate.