Ackermand et al.(2006): Lazulite-bearing metaquartzite of the Itremo Group (Central Madagascar); Scientific significance and economic importance in Proceedings of the Malagasy-German Research Cooperation in Life and Earth sciences, 5-18
The fastest fighter aircraft is the MiG 25, with speeds topping at Mach 3.2 (2,450 mph/4,000 km/h). Pilots were not allowed to go beyond Mach 2.8. Above Mach 2.8, the engines would overheat and burn up.
Full Answer. Some models of jets have been designed to reach much higher speeds than the average of 550 mph. Typically, these planes are designed for a limited number of passengers. One example is the Gulfstream G650 from Gulfstream Aerospace, which reaches speeds of up to 904 mph.