European carriers, such as Air France-KLM, Lufthansa and Virgin Atlantic, have outsourced heavy airframe maintenance for long-haul aircraft to MRO providers in Asia and other regions. Long-distance ferry flights are viable only for widebody heavy maintenance checks, says Sascha Leitner, head of network sales for aircraft base maintenance at Lufthansa Technik. This is particularly the case for aircraft with traditional letter checks, such as the Boeing 747, which require high numbers of man-hours. For example, Air France-KLM sends its 747s for D-checks to Asian MRO providers, but the airline group services its 777s in Paris and Amsterdam because the overhaul tasks are packaged into smaller C-checks. Rising fuel prices have led to higher ferry flight costs and thus reduced potential labour cost savings. This is aggravated by salary increases in Asia.