The Niki Lightning is a fully enclosed two-seater tricycle autogyro of composite construction, designed and built by Niki Rotor Aviation in Bulgaria. It was introduced in 2009[1] [2]
The Lightning's cockpit pod accommodates a pilot and passenger in tandem. The main rotor is two-bladed, with a pre-rotator. Unconventionally the tail boom is mounted though the centre of the propeller shaft.[3] The boom may be unbolted and removed to aid access to the engine and prop.
There is a choice of two very compact D-Motor engines (both liquid-cooled horizontally-opposed side-valve four-strokes): either the 950NaN0 4-cylinder LF26 or the 1300NaN0 6-cylinder LF39. The engine is sited behind the cockpit, driving a 3- or 4-bladed ground-adjustable pusher propeller which is coaxial with the tail boom. The D-Motor engines are direct-drive units redlined at 3,000 rpm. The engines are sited beneath the thrust line of the propeller; instead of using a gearbox, the Lightning uses a multi-belt-drive reduction system of about 3:2 ratio, resulting in an efficient propeller speed of up to 2,000 rpm.[4] This arrangement avoids the necessity of a tailboom beneath the propeller, giving a smoother empenage and reducing drag. Beneath the tail-fin a spring-steel tailskid is fitted, to inhibit propeller strikes.
Consuming some 15L of avgas per hour, the autogyro has an endurance of 4 hours, with 30 minutes reserve. Its cruise speed of 81kn gives the autogyro a range of over 320nmi. It has a take-off roll of 70m (230feet), and a landing roll of 20m (70feet).[2] The Lightning may be flown with its side doors removed.[5]
An alternative engine for the Niki Lightning is the Rotax 914UL (but the normal Rotax gearbox would be dispensed with in favour of the drive belts).[6]