This Day in McDonnell Voodoo History: June 28

In 1955, Phase II evaluation of the F-101A was completed.  Although the new “Type II” inlet ducts improved pressure recovery within the inlet duct, the F-101A would still encounter compressor stalls at high speed and altitude.  Range performance was 15% below predicted values, the afterburners would blow out at high altitude, and lateral control was not as desired.  Work on the engines to improve surge margin and alleviate compressor stalls, along with changes to increase cruise efficiency, were undertaken by Pratt & Whitney while McDonnell worked on further improvements to the inlet ducts to eliminate compressor stalls during maneuvering flight.

First Photo: Maj. Austin A. "Gus" Julian at the controls of the second F-101A, 53-2419, which had been held on the production line for installation of the new Type II inlet ducts.

Photo Credit: National Archives and Records Administration via Mark Nankivil.

Second Photo: The first two ships in formation over Edwards AFB.  The longer Type II inlet ducts on 53-2419, in the foreground, are redily noticeable compared to the smaller Type I ducts of the original aircraft.

Photo Credit: National Museum of the United States Air Force via Mark Nankivil.