[3] In 1927 he rejoined the Loughead brothers and their newly founded (in 1926) Lockheed Aircraft Company, working as chief engineer on the Lockheed Vega, the civilian transport monoplane with a cantilever wing that produced unusually high performance for that period, and was widely used by such top pilots as Wiley Post, Amelia Earhart, and Hubert Wilkins.

[9] The flying wing and the pursuit of low drag high lift designs were Northrop's passion and its failure to be selected as the next generation bomber platform after World War II, and the subsequent dismantling of all prototypes and incomplete YB-49s, were a severe blow to him.

[10][11] He broke a decades-long silence on the Flying Wing's demise in a 1979 television interview,[12] accusing the Air Force of killing the project to punish him for refusing to merge his company with Consolidated Vultee.

[9] Symington called the charge "preposterous and absurd" and told a researcher[13] "There was a tremendous overcapacity in the industry following World War II".

"[9] Aviation expert Bud Baker, who studied declassified documents and public records and conducted personal interviews with Symington, Air Force generals and Northrop's chairman, concluded the cancellation "was a sound decision, based on budgetary, technical, and strategic realities.

In 1976, with his health failing, he felt compelled to communicate to NASA his belief in the low drag high lift concept inherent in the flying wing.

NASA replied that the idea had technological merit, encouraging Northrop that his flying wing concepts had not been completely abandoned.

[15] B-2 project designer John Cashen said, "As he held this model in his shaking hands, it was as if you could see his entire history with the flying wing passing through his mind.

In 1947 he received the Spirit of St. Louis Medal from the American Society of Mechanical Engineers for "meritorious service in the advancement of aeronautics.