Staff Writer (Updated: 4/4/2016):
The AW109's design was that of a sleek and aerodynamically-refined aircraft featuring a well-sloped and pointed nose assembly. The cockpit was set well ahead in the design with seating for two pilots behind a two-piece forward windshield for excellent visibility out of the cockpit. Entry and exit from the cockpit was through hinged automobile-style doors fitted to either side of the cockpit. Aft of the cockpit was the passenger cabin with variable seating or medical litter options. Search and Rescue types were outfitted with specialized equipment for their given role and armed versions showcased door-mounted machine guns. Entry and exit to the passenger cabin was via rectangular sliding doors to either side of the cabin, these doors sliding rearwards against the helicopter's body. The powerplant was fitted above the cabin roof in the usual way and powered a four-bladed main rotor atop a short mast as well as a two-bladed tail rotor at the rear (the tail rotor facing portside). The empennage consisted of a tapered assembly which housed the tail rotor shaft within. The tail unit was slightly raised from the fuselage underside and capped at its aft end by a large dorsal and smaller ventral vertical tail fin. Horizontal stabilizers were set along the tail stem near the rudder. The undercarriage consisted of two single-wheeled main legs and a single-wheeled nose leg, all were retractable into the floor of the A109 (on most production versions).
The AW109 first appeared in the aptly-designated A109A production model fitted with 2 x Allison Model 250-C20 American turboshaft engines. The A109A EOA was a specially developed militarized version for service with the Italian Army while the A091B proved another militarized model that fell to naught. The A109A was modernized through the A109A Mk II initiative and this begat a MEDEVAC version as the A109A Mk II MAX. The A109C grew into a commercial passenger model sporting 2 x Allison Model 250-C20R-1 turboshaft engines with seating for eight and was followed by a MEDEVAC as the A198C MAX.