Entire B-1B bomber fleet grounded over fuel pump filter housing problem 1 hour ago A B-1B Lancer sits on the flightline while receiving a post-flight inspection Nov. 9. (Airman 1st Class Joshua Seybert/U.S. Air Force) The Air Force has again pulled its entire B-1B bomber fleet from the skies as it investigates problems with a part of the fuel system. Gen. Tim Ray, head of Air Force Global Strike Command, indefinitely grounded the service’s 57 active Lancers amid safety concerns April 20, a command spokesperson said Friday. The War Zone first reported the standdown. “During the inspection process following a B-1B ground emergency on April 8 at Ellsworth Air Force Base, South Dakota, a discrepancy with an augmenter fuel pump filter housing was discovered,” the command said. “As a precautionary measure, the commander directed one-time inspections on all B-1B aircraft to resolve this issue.”