WASHINGTON (AP)--The Air Force said Monday a piece of faulty steel in a wing led to the 15th crash of an F111 aircraft last Dec. 22 at Nellis Air Force Base, Nev.
  The accident killed two crewmen and led to grounding of all the variable sweep F111s.
  The victims were Thomas J. Mack, 38, formerly of Viola, and a son of Mr. and Mrs. Bert Mack of Viola, and Major John Anthony of Big Springs, Tex.
  Secretary of the Air Force Robert C. Seamans Jr. said investigation showed the accident was caused by structural failure of the left wing "stemming from a pre-existing defect in the steel used in a pivot fitting where the wing joins the fuselage."
  The Air Force said it will inspect its more than 200 F111s to seek whether they have similar defects. Until those inspections are completed, the plane will remain grounded.
(Rock Island Argus - Tuesday, January 13, 1970)