Another important advantage of the engine is increased load capacity. The HTS900 adds 208shp to the helicopter compared to the legacy engine, without an increase to the size of the propulsion system. The added power means that at 4,000 ft., the Eagle 407 HP upgrade carries a 5% heavier load than a standard 407 aircraft with the production engine. The capacity differential increases to 16% at 8,000 ft., and 20% at 10,000 ft. (Load comparisons are based on hover out of ground effect (HOGE) at ISA +20C.)

The ability to increase payloads at high altitude permits the deployment of full onboard mission equipment and fuel capacity. This, in turn, yields a greater likelihood of mission completion without the need for multiple flights.

This performance significantly expands the scope of operations that are possible for light utility helicopters with the HTS900 engine. Among applications that Honeywell sees for the Eagle 407 HP upgrade are carrying heavier sling-loaded equipment, moving large oil and gas field components such as rigs, and equipping search-and-rescue and other emergency helicopters with higher load-bearing winches.

Honeywell is targeting a specific market with the upgrade: operators that routinely fly heavy loads at high altitude. A representative estimates that 336 light utility helicopters worldwide would see an immediate performance benefit from an HTS900 retrofit.

The HTS900 engine owes its capabilities to innovative design features developed by Honeywell. These include a durable dual-centrifugal compressor, cooled single-crystal high pressure turbine blades, an effusion-cooled combustor liner and a dual-channel, full authority digital engine control (FADEC) that regulates torque and facilitates engine and maintenance planning and trouble-shooting.

Honeywell views the HTS900 engine as a module to which performance enhancements can be added. The engine has thus far been used as a forward-fit or upgrade on single- engine platforms. Honeywell is looking at offering the HTS900 for twin-engine helicopters as well.

The engine’s features have gained enough notice in the industry that one OEM specified the HTS900 as a forward-fit for a multipurpose light helicopter that it promotes as the industry’s first entirely new, single-engine design in 40 years. The OEM is Marenco Swisshelicopter AG of Mollis, Switzerland, and the new model is the 2.5-ton SKYe SH09. Features of the SKYe SH09 include a carbon-fiber body, which is lightweight and generates low vibrations, and a modular interior that seats up to eight and can be quickly reconfigured for cargo, medevac, search and rescue, surveillance, law enforcement and other uses. Specifying the HTS900 engine boosts the helicopter’s performance in key areas, Marenco officials explain, while reducing total operating costs.

The helicopter, which will cost around $3 million, made its first flight in October 2014. Production is slated to begin in late 2015 or early 2016. About 60 orders were placed for the aircraft by the end of 2014.