American aeronautics engineer and industrial designer (1895-1981). ALS signed “John K. Northrop, US Plane Designer-Builder 1916–1952” at the top, one page, 7.25 x 10.5, personal letterhead, April 5, 1969. A response to some questions from an aviation enthusiast. In full: “Lockheed Vega, Designed in 1926 was one of my early successes. Later I pioneered the smooth-skin all metal type of construction in general use since 1932. I also designed the US P-61 night fighter (’Black Widow’). This was the 1st US planes equipt with radar, permitting detection without direct vision.” In fine condition, with scattered wrinkling and a uniform shade of mild toning. RRAuction COA.
