UNIS-NA Design NA-40 "Bongo"


NA Design was created in third quarter of 1999, in co-operation with Moravan Aeroplanes Inc. Development of the (formerly UNIS) Bongo continued into early 2002, at which time NA Design was seeking a Western partner to assist with certification, production and marketing; the project was put on hold in late 2002 while finance was sought but, despite this, a new version, the four-seat NA50, was announced in late 2002. Some US$2.5 million said to be required to bring aircraft to production readiness.


TYPE: Two-seat ultralight helicopter.

PROGRAMME: Design work 1992 followed by model tests 1993; construction of Bongo technology demonstrator started 1996; public debut at Ârno International Machinery Fair 1997 (then called TINTS NA40 and with two-blade main rotor) by first prototype OK-CIU. Began 70 hours of tethered hover flights March 1998. Two further prototypes completed by mid-1998. NA Design plans Normal category certification to FAR Pts 27, 33, 34 and 36 by late 2003, subject to finding joint venture Western partner to share certification, manufacturing and marketing costs. However, by 2002, financial support of US$2.5 million was still being solicited, but nothing further had been heard by early 2003.


  • NA 40 Bongo: Basic civil version; as described.
  • NA 42 Barracuda: Proposed military/police version. Power plant as NA 40 or single Rolls-Royce 250 engine; stub-wings for weapons carriage; undernose sensor turret; intercom. Otherwise generally as NA 40.
  • NA 44 Bion: Projected UAV version of NA 42 for various military and civil applications.
  • NA 50: Proposed four-seat version announced in late 2002 with estimated unit cost of US$1 million.

COSTS: Approximately US$750,000 (2001).

DESIGN FEATURES: Three-blade teetering rotor; pod and boom fuselage with inverted Y-tail unit. Cocomo patented anti-torque system eliminates need for tail rotor, reduces transmission complexity and operating noise level.

FLYING CONTROLS: Conventional cyclic and collective controls. Ducted air anti-torque system.

STRUCTURE: Mainly composites, including rotor blades; some aluminium in fuselage, otherwise double-curvature monocoque sandwich; laminated, vacuum-formed elastomeric rotor head.

LANDING GEAR: Tubular twin-skid gear with ground handling wheels. Inflatable permanent or emergency floats optional.

POWER PLANT: TWO 86kW Prvni Brnenska Strojina PBS Velka Bites ÒÅ 50Â turboshafts, with FADEC and dual ignition. Engines mounted side by side behind cockpit; transmission via combining gearbox. Single self-sealing fuel tank beneath engines, capacity 210 litres.

ACCOMMODATION: Adjustable, foldable and anatomically shaped seats for pilot and passenger. Baggage space aft of seats; provision for additional, aerodynamic baggage container under fuselage. Gull-wing window/door each side, hinged on centreline and opening upward.

SYSTEMS: Dual 27V DC electrical systems; external power receptacle.

AVIONICS: Instrumentation: VFR standard; IFR to be offered later.

EQUIPMENT: Rocket-deployed emergency recovery parachute optional.

Jane's All the World's Aircraft, 2004-2005


Technical data for NA40 Bongo

Rotor diameter: 7.48m, fuselage length: 6.15m, height to top of rotorhead: 2.35m, empty weight, equipped: 480kg, max load on external sling: 250kg, max take-off weight: 950kg, never-exceed speed: 280km/h, max cruising speed: 250km/h, econ cruising speed: 230km/h, hovering ceiling IGE: 4,000m, max range: 500km


NA 42 Barracuda

NA 44 Bion

NA 50