MBB Bo 105 Bo 105LS A3

The Bo 105LS (the L of the series reads as "Lift") was MBB's answer to hot-and-high operations, where the power of the Allison 250-C20Bs fell short. In 1984 the Bo 105LS was developed by combining the enlarged fuselage of the Bo 105CBS with uprated Allison 250-C28C turbines, with the twin aim of increasing the maximum take-off weight and improving hot-and-high flight performance. The German Wikipedia describes the L series as having a further strengthened powertrain, available from 1984, and lists its sub-variants: LS A-1, LS A-2, LS A-3 and LS B-1, the last a test prototype with PW105B turbines that did not enter production. The fuselage stretch, originally developed with Boeing Vertol, was adopted by MBB for the CS, CBS and LS versions.

The LS A1 of 1984 was the first version with the stretched fuselage and the 250-C28C. The LS A3, developed in 1986, raised the maximum take-off weight to 2,600 kg: its Allison 250-C28 engines deliver 373 kW (507 PS) each, against the 313 kW of the CB, and the version received its certification in July 1986. In 1995 came the LS A3 "Superlifter", with the maximum mission weight increased to 2,850 kg; according to the German Wikipedia, from October 1995 those 2,850 kg were cleared with external loads, that is, with cargo on the hook. The English Wikipedia compares the lifting capability of the Bo 105CBS-5 Superfive with that of the LS A3 Superlifter, which thus remained the highest-capacity Bo 105 of the family.

The industrial peculiarity of the LS is its Canadian origin. The main production facilities for the Bo 105 were located in Germany and Canada, and the Bo 105LS was manufactured under a cooperative arrangement with Eurocopter Canada, the group's North American subsidiary; the German Wikipedia records the Canadian certifications CDN-B, CDN-B4, CDN-BS, CDN-BS-2, CDN-BS-4 and CDN-BS-5 for the airframes of that line. Canada was also a natural market for the type: the Canadian Coast Guard operated Bo 105s until 2016, when its Bell 429s were delivered, and Canada's International Test Pilots School is listed among its operators. The last Bo 105 produced was bought in 2009 by the Canadian EMS specialist Dam Helicopters, so that the L series closed production of a family which, including licence production in Canada, Indonesia, the Philippines and Spain, reached about 1,640 aircraft, 1,404 of them built in Germany.

Taken together, the L series represents the growth ceiling of the Bo 105 within its original airframe: more engine and more weight on the same two-tonne airframe that had first flown on 16 February 1967, the first helicopter to feature a rigid, hingeless rotor head made of titanium and glass-fibre-reinforced rotor blades. According to Airbus, since the first delivery in 1970 more than 300 customers around the world purchased a total of some 1,400 aircraft, operated in air rescue, as police and military helicopters and for VIP, passenger and cargo transport; the Canadian-built LS was the member of that family that pushed lifting capability furthest. To go further, MBB and later Eurocopter turned to new designs, the BK 117 with Kawasaki and the Bo 108 that would become the EC 135.