355FX Conversion

Twin-engine light helicopters come with a specific set of design challenges for manufacturers. Is it to be an economical helicopter with an additional margin of safety, or fully mission-capable on a single engine? Is it to be lightweight and simple, or complex and robust? What role is it meant to fulfill?

The AS355 TwinStar embodies each of these design ideas through its various incarnations, and has fulfilled every role possible for a light twin. Heli-Lynx focuses on the older F1 and F2 versions, updating and improving them to deliver more adaptable platforms in the FX1 and FX2.

The FX electrical system was created to address the issues apparent in the earlier TwinStar models, before adaptation for the AStar. Gone are the overhead panel and glass fuses, the original wiring harness, the master electrical boxes, and the typical console. The OEM electrical system is replaced by the FX VFR electrical kit, employing two GCUs, a new main bus electrical circuit with a dedicated avionics buss and an isolatable essential buss. The power distribution and power generation panels are readily accessible via the aft baggage compartment, aiding in diagnosis and repair. All parts comprising the FX electrical kit are cost-effective and widely available from local suppliers.

The conversion makes further changes to solve historical headaches. Pilot workload is reduced through the aforementioned elimination of the overhead panel, coupled with a streamlined instrument console and simpler master switch panel to replace the push-button panel. Electroluminescent lighting strips increase instrument visibility and replace the old fibre light cables. Sealed push-pull cables replace the old Bowden spring-based engine control cables, ensuring immediate engine response without NR droop.

The FX process has the added benefit of reducing the equipped empty weight of the helicopters, making them more adaptable platforms. The transformation is significant enough that the FX1 and FX2 beat the AS350 B2 in terms of internal useful load, and rival the newer AS355 N model.

The 355FX conversion allows for several optional upgrades. Rolls Royce 250-C20R engines can replace the standard 250-C20F powerplants, increasing operational margins and improving performance in hot and high conditions. Coupled with this are the optional tail boom strake and wide-chord tail rotor for superior tail rotor authority.

The FX1 and FX2 offer low-cost options in a world of expensive light twins, with a proven track-record of reliability. Fast becoming favourites as corporate conveyances in busy metropolises such as New York City and Los Angeles, our TwinStars also serve as high-quality filming platforms and economical machines suited for urban operations.

Separate from the FX program, Heli-Lynx can perform several upgrades to the F1 and F2. For these options, please see the Maintenance section of the website.