BK 117
A BK-117 B2 of the German police in Northrhine-Westphalia
Role	Utility/transport
National origin	Germany / Japan
Manufacturer	Messerschmitt-Bölkow-Blohm (MBB) / Kawasaki Heavy Industries
First flight	13 June 1979
Introduced	9 December 1982
Status	Production
Produced	1979-
Number built	400+
Developed from	MBB Bo 105
Variants	Eurocopter EC 145

The MBB/Kawasaki BK 117 is a twin-engined medium utility/transport helicopter. It was a joint development between Messerschmitt-Bölkow-Blohm (MBB) of Germany and Kawasaki of Japan. MBB was later purchased by Daimler-Benz and eventually became a part of Eurocopter. The BK 117 is popular for passenger and VIP-transport, seating from seven up to 10 people. It is also used for aerial crane and sling work, law enforcement, military transport, and is exceptional as an air ambulance and search and rescue platform. A developed version of the BK 117 is produced as the EC 145.

Contents 1 Development 2 Variants 3 Operators 3.1 Civil operators 3.2 Military operators 4 Specifications (BK 117-A1) 5 See also 6 References 7 External links

[edit] Development

The BK 117 was a joint development between MBB and Kawasaki based on an agreement made on 25 February 1977. The agreement would replace two separate developments by both companies; the Bo 107 by MBB and the KH-7 from Kawasaki.^[1] Costs were shared equally, with MBB developing the rotors, tailboom, flight controls and hydraulic system and Kawasaki developing the landing gear, airframe, main transmission and other minor components.

Each company was to build two prototypes, to be completed by 1979; one for static ground testing and the other for flight testing. Delays at Kawasaki caused only one of the prototypes to be completed on time. However, the Kawasaki prototype first flew only several weeks later than the MBB prototype.^[1]

A single BK 117-A3 was leased by the Canadian Forces Air Command for a test program and designated as the CH-143. When the program was over, the aircraft was returned to MBB Canada.^[2]

Originally known as the BK 117-C2, the EC 145 combines the original BK 117 design with a much larger cabin, and modern features from the EC 135.

[edit] Variants

BK 117 P-2 

German prototype, first flown 13 June 1979.

BK 117 P-3 

Japanese prototype, first flown 10 August 1979.

BK 117 A 

Initial production version.

BK 117 A-1 

Powered by two Lycoming LTS 101-650B-1 engines.

BK 117 A-3 

Introduced in 1985, the A-3 has a larger tail rotor with improved blades, and the take-off weight increased to 3,200 kg (7,055 lb).

BK 117 A-4 

Introduced in 1986, the A-4 has increased transmission limits at take-off power, improved tail rotor head. German aircraft have provision for extra internal fuel, giving enhanced performance.

BK 117 A-3M 

Military version introduced in 1988. The A-3M is fitted with taller skids and can carry 11 troops. A Browning 12.7 mm (0.5 in) machine gun can be mounted under the fuselage in a Lucas turret with 450 rounds and controlled by a helmet-mounted sight. The A-3M also has outrigger pylons can hold up to eight HOT II or TOW antitank missiles or a variety of air-to-air missiles, rocket-pods, or forward-firing cannons. Provisions for a doorway gunner's position with a 12.7 mm (0.5 in) gun can also be installed.

BK 117 B-1 

Introduced in 1987, the B-1 is fitted with LTS 101-750B-1 engines to provide increased performance, and a 140 kg (309 lb) increase in payload.

BK 117 B-1C 

UK-cerified version with reduced range and endurance.

BK 117 B-2 

BK 117 C-1 

Powered by two Turbomeca Arriel 1E engines. Later models may be upgrated to Arriel 1E2 engines.

BK 117 C-2/EC 145 

powered by two Turbomeca Arriel 1E2 engines.

NBK 117 

License-built model produced in Indonesia.

[edit] Operators

[edit] Civil operators

The majority of the helicopters are operated by various emergency services although it is also operated by private individuals, companies and executive charter operators.

 Puerto Rico

• Puerto Rico Police Department

[edit] Military operators

 Canada

• Canadian Forces Air Command - A single BK 117-A3 was leased by the CF for a test program and designated as the CH-143. When the program was over, the aircraft was returned to MBB Canada.^[2]

 Chile

• Chilean Air Force

 Colombia

• Colombian National Armada

 South Africa

• South African Air Force

[edit] Specifications (BK 117-A1)

This aircraft article is missing some (or all) of its specifications. If you have a source, you can help Wikipedia by adding them.

Data from {All the World's Rotorcraft}^[1]

General characteristics

• Crew: Two pilots
• Capacity: 10 passengers (varies by model)
• Length: 13 m (35 ft 6 in)
• Rotor diameter: 7 m (36 ft 1 in)
• Height: 3.85 m (12 ft 7 in)
• Empty weight: 1,650 kg (3,630 lb)
• Max takeoff weight: 2850 kg (6,270 lb)
• Powerplant: 2× Avco Lycoming LTS 101-650B-1 turboshaft, 410 kW (550 shp) each

Performance

• Maximum speed: 262 km/h (141 kn, 163 mph)
• Cruise speed: 250 km/h (135 kn, 154 mph)
• Range: 541 km (292 nmi, 333 mi)
• Service ceiling: 4,570 m (14,990 ft)
• Hover ceiling: 2,530 m (8,300 ft)

[edit] See also

• Helicopter
• Air ambulance
  

Related development

• MBB Bo 105
• Eurocopter EC 135
• Eurocopter EC 145
  

[edit] References

[edit] External links

Wikimedia Commons has media related to: MBB/Kawasaki BK 117

• Manufacturer's website
• BK 117 in aeromedical services

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