In late 2010, simulated icing tests were performed on the MSN1 flight test aircraft using devices installed on the wing's leading edges. These revealed an aerodynamic issue causing horizontal tail buffeting, resolved via a six-week retrofit to install anti-icing equipment fed with bleed air; production aircraft are similarly fitted. Winter tests were done in Kiruna, Sweden during February 2011. In March 2012, high altitude start and landing tests were performed at La Paz at 4,061.5 m (13,325 ft) and Cochabamba at 2,548 m (8,360 feet) in Bolivia.