Honeywell engineers are developing for the AgustaWestland AW139 medium twin a software upgrade that optimizes the helicopter’s Primus Epic avionics system for the rigors of search-and-rescue operations.
Phase 5 features that recently underwent flight testing at Honeywell in Phoenix included automated search patterns, automatic radar altitude hover, a “fly-up” safety limiter and other autopilot functions intended to ease workload and enhance safety for AW139 crews performing SAR missions in demanding environments. The radar altitude hover function, for example, will allow the AW139 to hover automatically in rough seas with wave heights of 20 feet, while the safety limiter will automatically climb away from bigger waves. The Phase 5 upgrade will also add a winchman trim feature that lets the hoist operator maneuver the helicopter from the cabin.
A Phase 4 software upgrade for the AW139’s Primus Epic cockpit certified in March added a host of advanced capabilities, including a hover display for controlling auto hover functions, four-axis autopilot and flight director, VGP (Vnav glidepath) approach capability, 7.5-degree approach capability and FMS heliport approaches. Future enhancements to the AW139’s Epic suite are expected to include WAAS/LPV approach capability, low RNP approaches, ADS-B, charts and maps display and an optional XM weather receiver.
The functionality in the AW139 FMS is identical to that of the flight management systems used in Gulfstreams flying with the PlaneView cockpit. This caused some confusion during a demo last month when an error inputting the fuel-flow values into the FMS rendered the GPS approach capabilities useless. The problem wasn’t discovered until the crew was trying to execute a VGP approach. Because the proper performance data hadn’t been entered into the FMS before takeoff, the system refused to accept the VGP approach. Honeywell senior technical manager James Nicholls said the error was corrected on the next flight.
The AW139’s cockpit includes four 8- by 10-inch LCD flight displays, dual FMS, helicopter EGPWS, TCAS I, Primus 660/701 weather radar and HUMS (health and usage monitoring) in addition to a suite of nav and com radios. Nicholls said Honeywell will incrementally upgrade the AW139 flight deck based on AgustaWestland’s schedule. With Phase 5 flight testing finished, Honeywell expects certification soon. Additional advanced features will take somewhat longer.