Neiva BN-1

National origin: Brazil
Manufacturer: Neiva (Sociedade Constructora Aeronautica Neiv, LTDA, Rio de Janeiro
Designed by: José de Carlos de Barros Neiva.
First flight: c.1955
Number built: at least 4

The Neiva BN-1 was a high performance single seat sailplane designed in Brazil in the 1950s. It had national record and competition success and went into production for club use.

Design and development

The BN-1 was a conventionally laid out wooden single seat glider, with a high mounted cantilever wing . This had an aspect ratio of 19 and was built around a single I-section spar with 2° of dihedral. The leading edge and upper surface was formed from plywood, the underside fabric covered. The ailerons were wooden framed with fabric covering; the spoilers were wooden. The fuselage was a wooden monocoque with the cockpit and its moulded plexiglass canopy just ahead of the leading edge. Behind the wing the fuselage was quite slender, carrying the cantilever tailplane just above it on a slight step. The vertical tail had a largely straight, slightly raked leading edge, with a small fuselage fillet and a rounded tip turning into a broad, curved edged rudder. The tail surfaces were all wood framed and fabric covered. The BN-1 landed on a forward skid and a retractable monowheel just aft of the centre of gravity.

Operational history

The BN-1 went into production for the Brazilian government-run National gliding clubs. It was placed first at the second National Soaring competition. At the third National Soaring competition, four BN-1s took first, second, third and fifth places against twelve European and US aircraft. The BN-1 also set three Brazilian records, including a 332 km (206 mi) goal flight.

Specifications

Data from Jane's All the World's Aircraft 1956/7

General characteristics

Crew: 1
Length: 6.90 m (22 ft 8 in)
Wingspan: 16.0 m (52 ft 6 in)
Height: 1.02 m (3 ft 4 in)
Wing area: 13.47 m (145.0 sq ft) gross
Aspect ratio: 19
Airfoil: NACA 4415 at root, NACA 4412 at mid-span and NACA 2R1 12 at tip
Empty weight: 170 kg (375 lb)
Gross weight: 250 kg (551 lb)

Performance

Maximum speed: 225 km/h (140 mph; 121 kn) maximum safe
Stall speed: 50 km/h (31 mph; 27 kn)
Maximum glide ratio: best, 1:31 at 76 km/h (47 mph)
Rate of sink: 0.54 m/s (106 ft/min) minimum, at 60 km/h (37 mph)

Neiva BN-1 Pictures

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Source: WikiPedia