2000 M. P. H.?
Fastest Flight Caused Death of U. S. Pilot

Capt. Milburn G. Apt, killed last month in the crash of the X-2 rocket research plane, was flying faster than any other human being has ever flown, air force Secretary Donald Quarles disclosed yesterday at Spokane Wash.

The speed attained by apt, shown by instrument records of his flight, was not disclosed by Quarles, but his announcement put the figure at better than the reported 1900 m.p.h. reached in the same research craft by Lt. Col. Frank (Pete) Everest.

Light on Crash
Air observers were surprised to learn that Apt hit perhaps 2000 m.p.h., pointing out that the flight was his first in the X-2 and was described as a "familiarization" flight rather than an all-out research run. However, the fact that Apt was scorching through the stratosphere at such a phenomenal speed could offer some explanation for his crash which heretofore had been a mystery.

Lt. Col. Charles (Chuck) Yeager almost lost his life in the X-1A, a predecessor aircraft, when the ship went out of control at 1650 m.p.h. and fell thousands of feet before Yeager could regain control. Quarles, speaking before the general conference of the National Guard Association, eulogized Apt for giving his life "to penetrating and rolling back the frontiers of knowledge in aerodynamics."

From Washington, meanwhile, came another unofficial report on the X-15, a North American Aviation research plane disclosed in The Times a year ago.

The report said the X-15 will be capable of flying at speeds exceeding 4000 m. p. h. and altitudes above 38 miles.

Unofficial information obtained by this newspaper, however, indicates the North American plane's speed will be in the 2000-3000 m.p.h. range, while its ceiling—with altitude as it primary research area—will be an incredible 100 miles or more, better than 528,000 feet with a pilot aboard.

Published reports have said that loss of the X-2, after several successful research missions, including an ascent to about 126,000 feet, was made relatively less important by the fact that the X-15 is being developed.

Authorities feel, however, that this is not true. they pointed to the fact that the sweptwing Bell bullet had not yet been turned over to scientists for step-by-step research into the heat barrier which it was designed to investigate.