AirLife Denver flew Bell 407s for 20 years before upgrading to an Eagle 407 HP conversion in July. The extra power and high/hot capabilities from the Honeywell HTS900 engine has enabled the Air Methods program, based at the Sky Ridge Medical Center (altitude 6,000 feet) in Lone Tree, Colorado, to accomplish intercity medical transfers with much greater safety margins on Denver’s notoriously hot summer days and also enabled the program to do scene work at altitudes up to 9,200 feet, said pilot Greg Poirier.
Poirier, who logged about 40 hours in the helicopter over the last four months, said the extra power translates into extra load carry capacity of anywhere from 400 to 700 pounds, depending on conditions. “We operated a standard 407 for 20 years and made it work, but this is a pretty big deal for us,” he said.
“It’s a substantial increase in performance at the temperatures and altitudes we operate out of—700 pounds more payload from our base at Sky Ridge. On a very hot day, say 96 to 98 degrees, we’d be at 4,400 to 4,800 pounds to get out in a stock 407 and with this one it’s 5,000 pounds no problem, even 5,200 to 5,400 pounds. You’ve got a pretty big margin,” Poirier said. Air Life also has the helicopter kitted out with additional items, including air conditioning and autopilot.
Pilots won’t notice any appreciable difference in fuel burn compared to a stock 407, around 45 to 50 gph, Poirier said, despite all the extra power. The engine has dual-channel Fadec, runs hotter, and burns cleaner. They will notice a different sound. “The engine sounds different than that of a stock 407. It is not as loud and runs at a pretty standard rpm. It feels like it is not revving up and down as much.”
To date, Air Life mechanic Dan Metz believes the 407 HP engine will require less maintenance intensive than a comparable stock engine. “The biggest difference is that it is not a segmented engine, so you can’t change out a compressor or a turbine. Up to this point we really have not had much to do on the engine at all. We’ve done standard inspections, typical of any turbine, and changed the oil. At 2,400 hours the engine will come out and go over to Intermountain Turbine for inspection; at 600 they will come out and do a boroscope inspection that takes about a day. But Eagle did a good install, everything is made well to fit.”
To date, Eagle has sold 25 of the $925,000 conversions and delivered 22, 19 in North America, with a heavy concentration to utility customers who are contract firefighters who find the high/hot weight advantage appealing, said Eagle’s David “Spyke” Whiting. Customer costs average around $725,000 Whiting said as they are allowed to keep the old engine. Currently, the Eagle 407 HP conversion has received certification approvals in China, Indonesia, Papua New Guinea, Australia, Canada, US., Mexico, Chile, and EASA approval is pending. The company is averaging one installation per month. Customers are currently limited as to avionics compatibility, with those preferring glass panel displays typically opting for the Garmin G500H, Whiting said. He added that Eagle is currently in discussions with Garmin about the possibility of offering a combined engine/avionics package in the future.