Watch as a 'chuteless statistician is sucked from an airplane and spends his final moments calculating exactly how many moments he's actually got left. The answer is 3:48.
At 43,000 feet, you would likely go unconscious from hypoxia in less than a minute, then maybe wake up somewhere between 10,000 to 8,000 feet. Airplane pilots require supplemental oxygen above 12,000 ft. Above 35,000 feet, the FAA requires that the pilot wear a fully sealed oxygen mask at all times, even in a pressurized cabin, just in case the cabin loses pressure, because the hypoxia would cause such a quick effect there's not enough time to put one on and still maintain control of the aircraft.