From https://familysearch.org/ark:/61903/1:1:VGR1-F4T

Warren G Walker

Death  12 May 1970
Event Place Kern, California, United States
Birth Date 23 May 1926
Birthplace Colorado

From http://www.newspapers.com/newspage/61293798/:

May 13 1970: A C101 cargo plane crashed on its sixth take-off during tests at Edwards Air Force Base yesterday, killing all four men on board. The four - engine craft, owned by Aerospace Lines of Santa Barbara, was on a certification flight for the Federal Aviation Administration. It burned after plummeting to the ground shortly after leaving the huge base's main runway. The base is located about 45 miles west of Barstow. Killed were Van II. Shepherd 4, of Santa Barbara, a vice president of Aerospace Lines and pilot for the flight; Harold Hansen, 44, of Golota, co pilot and the firm's chief test pilot; Travis B. Hidges, 44, of Santa Barbara, the flight engineer, and Warren Walker, of San Diego, a test observer from the Convair Division of General Dynamics Corp in San Diego. The C101 is the newest and smallest model of the Guppy series, all of which have bulbous cargo holds. Earlier models have been used to transmit missile sections and other large air cargo. An Aerospace company official said he could make no comment on any details of the crash until the FAA…