Britten-Norman Islander celebrates 40th anniversary

 - October 16, 2006, 10:56 AM

Forty years after its June 1965 first flight, the Britten-Norman BN-2 Islander remains in production, and more than 800 of the 1,250-plus airplanes delivered remain operational. The rugged, maid-of-all-work design is employed in myriad applications, including air taxi, charter and scheduled services; crop-spraying; water-bombing; VIP/executive operations; photo-reconnaissance/surveillance; air ambulance; para-dropping; and law enforcement.

John Britten and Desmond Norman, aerospace engineers who met at the de Havilland Aeronautical Technical School, founded Britten-Norman Ltd in 1963 and set up shop at Bembridge, on the Isle of Wight, off Britain’s south coast.

Perceiving a demand for small utility aircraft and with one light aircraft already to their name, they designed this simple, inexpensive piston twin to carry more than six passengers. They aimed at minimum capital cost per saleable seat for short-haul operations, while combining good short-field performance with rugged construction.

The BN-2 Islander began as a fabric-and-steel design before becoming a light-alloy monocoque. The deliberately simple configuration incorporated a high, flat parallel-chord wing, rectangular fuselage cross-section and fixed landing gear. The five bench seats could accommodate 10 people (including pilot), each row accessed through its own door. Base price was £17,500 ($42,000 at mid-1960s values).

The prototype flew on June 13, 1965, powered by 210-hp Rolls-Royce/Continental IO-360-B engines, and appeared at the Paris Air Show four days later. The company subsequently replaced the engines with more powerful 260-hp Lycoming O-540-Es (further outboard in longer cowlings on a longer wing) to ensure single-engine climb performance. The first production machine flew in April 1967, with customer deliveries following UK certification in August 1967; U.S. approval came four months later.

U.S. distributor Jonas Aircraft immediately ordered 30 (thus earmarking 50 percent of the 1968 production output) and another 112 within a year. Transatlantic deliveries required four 54-gallon long-range fuel tanks, the first delivery involving a 2,260-mile nonstop flight from Gander, Newfoundland, to Fort Lauderdale, Fla. One airplane, which made an emergency landing on Greenland’s icecap, was abandoned.

In 1969, an Islander won the London-Sydney air race, providing valuable exposure for B-N. This increased pressure on limited production capacity, but the company had reached an agreement the previous year for Romania’s Intreprinderea de Reparat Material Aeronautic (IRMA) to license-build 215 green aircraft, which would be flown “green” to Bembridge for completion. The first flew in August 1969 and IRMA production ran at 30 to 40 a year. By 1977, another 100 had been contracted. IRMA has produced all subsequent Islanders.

Mtow was increased in 1968 from 5,700 pounds to 6,000 pounds on the BN-2A Islander II, with lower-drag cowlings and undercarriage, improved interior and a bigger rear cargo area with external access. To improve hot-and-high performance, in 1970 the company added 300-hp Lycoming IO-540-K1-B5 fuel-injected engines, and optional tiptanks and a longer nose to house baggage. Jonas Aircraft developed Rajay turbocharger modifications for 260-hp versions, while Rolls-Royce produced 285-hp turbocharged versions of the Continental TSIO-520 for the BN-2S.

The Trislander

Seeking more capacity, in 1968 B-N flew a stretched BN-2E Islander Super variant, incorporating an additional seat row and powered by 350-hp Lycoming O-720 engines but did not certify it. Instead, it developed the BN-2A Mk III Trislander, a design that was a triumph of practicality over aesthetics. This featured a 90-inch stretch, stronger rear fuselage and undercarriage and a third Lycoming O-540-E4C5 engine mounted atop a longer-chord tailfin. The 17-passenger “feederliner” famously appeared at the 1970 Farnborough Air Show on the day of its first flight.

Trislanders were constructed from standard Islanders on a single production line, the first being delivered in June 1971. Variants with autofeathering propellers or auxiliary rocket-assisted takeoff were designated BN-2A-3 or -4, respectively. A military Trislander M was offered. Eighty-one Trislanders, including kits, were produced by 1984.

At the 1971 Paris Air Show, B-N unveiled a heavier, 6,950-pound-mtow Defender military variant, with underwing hard points for stores or weapons and internal provision of medevac or electronic equipment. Nose-mounted radar was offered and the Defender has found a ready market in more than 20 countries.

Financial Woes

Continuous development came with a cost, however, and within weeks of the Defender’s launch, financial problems led B-N Ltd into receivership (bankruptcy protection) in October 1971. The business was reformed as Britten-Norman (Bembridge) Ltd and acquired by Britain’s Fairey Group in August 1972, becoming part of holding company Fairey Britten-Norman (FB-N).

A week later orders for more than 40 Islanders were reported at the Farnborough Air Show (another 45 were taken in the ensuing nine months), as the new owner prepared to move production to Belgian subsidiary Fairey SA. The BN-2A-3S with extended-nose baggage space and extra seats in a reworked rear fuselage was also introduced at Farnborough.

So popular was the Islander that in 1974 sales passed the 548-order record for British multi-engine commercial aircraft and the company signed a license arrangement with Philippine Aerospace Development for progressive production of 100 Islanders, including 60 complete aircraft, using local subassemblies and components, and with FB-N buying 25.

Britten and Norman left the business in 1974, but development continued with a 6,600-pound-mtow, amphibious BN-2A-30. Twin floats were attached to the undercarriage legs and the fuselage incorporated retractable landing gear.

In 1976, UK propeller manufacturer Dowty Rotol used an Islander to test its Ducted Propulsor, which addressed possible future noise legislation. Fitted to wing-mounted pylons, Lycoming IO-540 engines drove seven-blade fans contained in 48-inch-diameter cowls. The tests demonstrated a 20-dB noise reduction (to 65-dB) as well as increased thrust and reduced pollution.

Firefighting and agricultural versions of the conventionally propelled Islander followed: the Islander Firefighter held 211 U.S. gallons of water or fire retardant, which could be discharged in 2.5 seconds. Agricultural variants had a liquid/powder hopper for up to 1,742 pounds of chemicals on each wing. The BN-2A-40 600-shp Lycoming LTS101-powered Turbo Prop Islander flew in April 1977, but it was sidelined because of requirements for significant strengthening and engine-reliability questions.

Ownership changed again in 1978 when Switzerland’s Oerlikon Buerle bought the company to establish Pilatus Britten-Norman and returned production to Bembridge.

A product-improvement program introduced the 6,600-pound-mtow BN-2B Islander II, which had a revamped cockpit and quieter cabin. In 1980 the company resurrected turboprop plans with 400-shp Allison 250-B17Cs powering the BN-2T Turbine Islander and Defender. The BN-2T entered service in 1981, and by the following year the 1,000th Islander had been delivered.

Later military development included the 1987 AEW Defender for airborne early warning, the 1994 BN-2T-4R with multi-mode radar in a large nose radome, and in 1997 the heavier, stretched BN-2T-4S Defender 4000. Since 2000, Omani interests have owned the business, trading now as BN Group. The BN-2B remains the current model, although development continues–including possible propeller, instrumentation and airframe changes that could be applied to a new variant.