FSX North American XB-70 Valkyrie. This is an update for FSX of Massimo Altieri’s XB70. The author has updated the flight dynamics, changed or added gauges to the 2D and VC panels, changed the 2D background picture a bit, changed the smoke effects and the afterburner effects. The aircraft will now stay stopped on the runway with zero throttle and less than 10 percent fuel. This is the whole aircraft. By Bob Chicilo.