The Trislander (Britten-Norman Trislander)

History

The three engined Trislander takes its inspiration from the configurations of trijets such as the L-1011 and DC-10 in its answer to the need for more power for a stretched version of the Islander (described separately).

Britten-Norman research showed that there existed sufficient market demand to warrant the development of a stretched Islander, and the company concluded that any stretched version would need to offer a 50% increase in internal capacity. The company's novel approach to the need for more power was to add a third engine, rather than two engines of increased power output. A nose mounted engine in the fashion of the Ju-52 was considered, but due to the Islander's nose configuration, BrittenNorman settled on mounting the engine on the vertical tail, resulting in the BN-2A Mk.3 Trislander.

The tail mounted engine involved significant modification to the tail and strengthening of the rear fuselage. Other changes over the Islander include a 2.29m (7ft 6in) fuselage stretch forward of the wing, new main landing gear and larger diameter wheels and tyres.

The first Trislander was in fact converted from the second Islander prototype, and it made the type's first flight on September 11 1970. Early production Trislanders were also conversions of Islanders, while subsequent Trislanders were built on the same production line as the Islander. The first production Trislander flew on March 6 1971, certification was granted on May 14, and first deliveries to a customer occurred on June 29 that year.

Britten-Norman Trislander production ceased in 1982 after 73 were ordered (by which stage the company had been acquired by Pilatus). Plans to produce the Trislander in the USA as the TriCommutair by the International Aviation Corporation, and in Australia never came to fruition. However one of 12 kits built for the TriCommutair project was assembled in Guernsey in the UK and flew in March 1996.

Design and development

Designed by John Britten and Desmond Roman, the Trislander is a further development of Britten-Norman's better-known Islander aircraft in order to give it a larger carrying capacity. In comparison with the Islander, the Trislander has a stretched fuselage, strengthened, fixed tricycle landing gear and a third engine on the fuselage centre line atop the fin.

The prototype of the Trislander, which was constructed from the original second Islander prototype, first flew on 11 September 1970. Initial production ceased in 1982 after 73 were ordered. As of January 2008, Britten-Norman was preparing a second production run of the Trislander.

The Trislander has exceptional low speed handling characteristics, extended endurance, increased payload, low noise signature and economical operating costs. Capable of taking off from a 450 metre long landing strip, the Trislander can readily operate from unprepared surfaces.

Variants

BN-2A Mk III-1

First production version, with short nose.

BN-2A Mk III-2

Lengthened nose and higher operating weight.

BN-2A Mk III-3

Variant certified for operation in the United States. Fitted with 3 blade propellers on the front two engines.

BN-2A Mk III-4

III-2 fitted with 350lb rocket-assisted takeoff equipment.

Trislander M

Proposed military version, not built.

Spesification

General characteristics

• Crew: 1 (2 with co-pilot)
• Capacity: 17 passengers (16 if co-pilot)
• Length: 49 ft 3 in (15.01 m)
• Wingspan: 53 ft 0 in (16.15 m)
• Height: 14 ft 2 in (4.32 m)
• Wing area: 337 ft² (31.31 m²)
• Empty weight: 5,843 lb (2,650 kg)
• Gross weight: 10,000 lb (4,536 kg)
• Powerplant: 3 × Avco Lycoming 0-540-E4C5 horizontally-opposed piston engine, 260 hp (194 kW) each

Performance

• Maximum speed: 167 mph (267 km/h)
• Range: 1,000 miles (1,609 km)
• Service ceiling: 13,150 ft (4,010 m)