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Bo 105

The Messerschmitt-Bölkow-Blohm Bo 105 is a light, twin-engine, multi-purpose utility helicopter developed by Bölkow of Stuttgart, Germany.  Production began under Messerschmitt-Bölkow-Blohm (MBB), which became a part of Eurocopter in 1991.  Eurocopter continued to produce the Bo 105 until 2001, when it was replaced in the product line by the EC 135. 

 

Development

The Bo 105A made its maiden flight on the 16th February 1967 at Ottobrunn in Germany with Messerschmitt-Bölkow-Blohm 's test pilot, Wilfried von Engelhardt, at the controls. The German Civil Aviation Authority certified the helicopter on 13 October 1970 and production for German civil and law enforcement organizations began shortly afterwards.  Further safety certification by the FAA was granted in April 1972 with United States export orders following.

The Bo 105C was developed in 1972 and the German Ministry of Defence selected this model for its light observation helicopter program, purchasing 100 helicopters in 1977.  A specialist anti-tank version armed with Euromissile HOT missiles and designated as the Bo 105PAH-1 was procured by the German Army around the same time, with a total of 212 eventually being delivered.

In 1976, the Bo 105CB was developed with more powerful Allison 250-C20B engines.  This was further developed as the Bo 105CBS with the enlargement of the fuselage by 10 inches to meet American market demands for emergency medical service operations, with this version becoming known as the Bo 105 Twin Jet in the United States.

In 1984, the Bo 105LS was developed with the enlarged fuselage of the Bo 105CBS combined with more powerful Allison 250-C28C engines to increase the maximum take-off weight.

Production ended in 2001, due to the Bo 105 being superseded by the more modern Eurocopter EC 135, after 1,406 machines had been built. The last Bo 105-LS was delivered in 2009 to Dam Helicopters Inc. of Nelson, British Columbia, Canada.

Being the first light twin-engined helicopter in commercial service, it gained widespread use over rural areas (police and EMS/medevac) as well as offshore.

The generally similar MBB Bö 106 featured a widened cabin seating three abreast in the front row and four abreast in the rear of the cabin.  The prototype, (D-HDCI), first flew on 25 September 1973, with hopes of new production as well conversion of Bo 105s, but nothing further came of the project.

 

Design

The four-blade rigid main rotor, a worldwide first, with fiberglass blades ensures high maneuverability.  A Bo 105CBS used for promotional purposes by Red Bull USA is fully aerobatic, performing loops, rolls, Immelmanns, and other maneuvers normally regarded as for fixed-wing aircraft only. All main systems (hydraulics, electric, fuel, lubrication) were designed to be fully redundant.

 

General characteristics

Crew: 1 or 2 pilots

Capacity: 4

Length: 11.86 m (38 ft 11 in)

Rotor diameter: 9.84 m (32 ft 3½ in)

Height: 3.00 m (9 ft 10 in)

Disc area: 76.05 m² (818.6 ft²)

Airfoil : NACA 23012

Empty weight : 1,276 kg (2,813 lb)

Max. takeoff weight : 2,500 kg (5,511 lb)

Powerplant : 2 × Allison 250-C20B turboshaft engines, 313 kW (420 shp) each

 

Performance

Never exceed speed : 270 km/h (145 knots, 167 mph)

Maximum speed : 242 km/h [ 16 ] (131 knots, 150 mph)

Cruise speed : 204 km/h (110 knots, 127 mph)

Range : 575 km (310 NM , 357 mi)

Ferry range : 1,112 km (600 NM, 691 mi)

Service ceiling : 5,180 m (17,000 ft)

Rate of climb : 8 m/s (1,575 ft/min)

 

Armament

Missiles: 6x Euromissile HOT (Bo 105 P) or 8x BGM-71 TOW