IAI Westwind

Design and development

The Westwind was originally designed in the United States by Aero Commander as a development of its twin-propeller namesake aircraft, first flying on January 27, 1963 as the Aero Commander 1121 Jet Commander. It was of broadly conventional business jet arrangement, with two engines mounted in nacelles carried on the rear fuselage. However the wings were mounted halfway up the fuselage instead of the typical low-wing arrangement of aircraft in this class. After successful testing, the aircraft was put into series production with deliveries to customers beginning in early 1965.

After initial testing of the prototype it was modified to production standard with an addition 2ft 6in to the fuselage length and increased payload and maximum weights. The second prototype first flew on 14 April 1964 which was followed by the first production aircraft in November 1964. Type approval was awarded by the FAA in November enabling the first customer delivery on 11 January 1965.

Operational history

Shortly thereafter, Aero Commander was acquired by North American Rockwell. The Jet Commander created a problem, since Rockwell already had an executive jet of its own design, the Sabreliner, and could not keep both in production because of anti-trust laws. Therefore, the company decided to sell off the rights to the Jet Commander, which were purchased by IAI in 1968.

Jet Commander production amounted to 150 aircraft in the United States and Israel before IAI undertook a series of modifications to create the 1123 Westwind. These included stretching the fuselage and increased maximum takeoff, maximum landing, and maximum zero-fuel weights, with the wing modified to incorporate double-slotted flaps and drooped leading edges and tip tanks. The trimmable horizontal stabiliser was also modified to have increased span and more travel. Not long after the aircraft went into production, the original General Electric CJ610 turbojet engines were replaced by more fuel-efficient Garrett TFE731 turbofans There were also numerous airframe modifications, such as drooped leading edges on the wings, a dorsal fin, revised engine pylons and nacelles, and further increases in maximum takeoff, maximum landing, and maximum zero-fuel weights. With improvements to a number of onboard systems incorporated as well, these changes resulted in the 1124 Westwind delivered from 1976.

In 1976, in the wake of the terrorist takeover of the Savoy hotel in Tel Aviv, the Israeli Air Force decided to use the Westwind as the basis for a maritime patrol aircraft, which became known as the IAI Sea Scan. It had originally been developed to meet a requirement for the United States Coast Guard to replace the Grumman HU-16 Albatross. The Dassault Falcon was selected instead.

In 1980, deliveries of the Model 1124A commenced; modifications included a new wing centre-section and the addition of winglets to the tips. The revamped aircraft was called the Westwind II, replacing the original design in production. IAI built its last Westwind in 1987, after a total of 442 Jet Commanders and Westwinds had been built, switching production to the Astra.

Aero Commander

1121 Jet Commander

Original production version, powered by two General Electric CJ610-1 engines developing 2,850 lbf (12,700 N) each; or modified with two CJ610-5 engines developing 2,950 lbf (13,100 N) each. A total of 120 were built including two prototypes.

1121A

Approved in 1967 the 1121A had overwing refuelling points with integral fuel tanks, new wheels, tires and brakes, improved cockpit lighting, maximum ceiling increased to 45,000 ft and all-up weigh to 17,500lbs, kept the CJ610-1 engines; 11 built.

1121B Commodore

Version manufactured with CJ610-5 engines; 19 built.

1121C

Unofficial designation for 1121 aircraft modified under a Supplemental Type Certificate with an increased all-up weight available from 1971.

1122

Improved version developed but not put into production; two aircraft built and subsequently converted to 1123 Westwinds.

IAI

1123 Westwind

Improved version of the 1121. The cabin was stretched by 0.51m (1 ft 8in) and the aircraft was fitted with more powerful CJ610-9 engines developing 3,100 lbf (14,000 N) each and a Microturbo Saphir III auxiliary power unit (APU). 36 built

1124 Westwind

Greatly improved version powered by two Garrett TFE731-3-1G turbofan engines developing 3,700 lbf (16,000 N) each, APU deleted.

1124 Westwind I

Name given to 1124 after introduction of Westwind II.

1124N Sea Scan

Maritime surveillance aircraft.

1124A Westwind II

Refined version of the 1124 built from 1980 onwards.

Civil operators

 Australia

Pel-Air: 6 of which 2 are in aero medical configuration.

 Canada

Royal Canadian Mounted Police

Discovery Air Defence

 United States

North Country Aviation, Gaylord, Mi. Chartered

FAA Federal Aviation Administration

Corporate Flight Management

Military operators

 Chile

Chilean Navy

 Ecuador

Ecuadorian Air Force

 Honduras

Honduran Air Force - one 1123 operated during 1976.

 Israel

Israeli Air Force

´ Mexico

Mexican Air Force: Inactive

 Panama

Panamanian Air Force - one 1123 delivered in 1975.

 Uganda

Ugandan Air Force - one 1121N operated from 1971 to 1976 as a presidential aircraft.

 United States

United States Coast Guard - one 1123 leased in 1973 for evaluation.

Specifications (1124A Westwind II)

Data from Jane's All The World's Aircraft 1982-83

General characteristics

Crew: Two (pilot & co-pilot)

Capacity: Up to 10 passengers

Length: 15.93 m (52 ft 3 in)

Wingspan: 13.65 m (44 ft 9½ in)

Height: 4.81 m (15 ft 9½ in)

Wing area: 28.64 m² (308.3 ft²)

Empty weight: 6,010 kg (13,250 lb)

Max. takeoff weight: 10,660 kg (23,500 lb)

Powerplant: 2 × Garrett TFE731-3-1G turbofan engines, 16.46 kN (3,700 lbf) each

Performance

Maximum speed: 868 km/h (469 knots, 539 mph) at 8,840 m (29,000 ft)

Cruise speed: 723 km/h (390 knots, 449 mph) econ cruise, at 11,890–12,500 m (39,000–41,000 ft)

Stall speed: 184 km/h (99 knots, 114 mph) CAS, flaps down, engines idling

Range: 4,430 km (2,392 nmi, 2,770 mi) with maximum payload

Service ceiling: 13,720 m (45,000 ft) (max certificated ceiling)

Rate of climb: 25.4 m/s (5,000 ft/min)