 Flight simulators for aircraft are also developed at this stage.Some commercial aircraft have experienced significant schedule delays and cost overruns in the development phase.Examples of this include the Boeing 787 Dreamliner with a delay of 4 years with massive cost overruns, the Boeing 747-8 with a two-year delay, the Airbus A380 with a two-year delay and US$6.1 billion in cost overruns, the Airbus A350 with delays and cost overruns, the Bombardier C Series, Global 7000 and 8000, the Comac C919 with a four-year delay and the Mitsubishi Regional Jet, which was delayed by four years and ended up with empty weight issues.