30 July 1935:
The Northrop 3A was a prototype pursuit built to compete for the U.S. Army Air Corps’ fighter contract. It flew against the Curtiss-Wright Model 75 Hawk, NX17Y, and the Seversky SEV-1XP, NX18Y. During flight testing, the Northrop entry was found to have undesirable spin characteristics and was returned to the builder for further work.
On the afternoon of 30 July 1935, 1st Lieutenant Arthur Henry Skaer, Jr., Air Corps Reserve, who was employed by Northrop as a test pilot, took off from Mines Field (now Los Angeles International Airport, LAX) to conduct spin tests.
Skaer never returned. An extensive search was conducted of the nearby Palos Verdes Peninsula and the southern California coastal waters. An Air Corps search plane spotted what appeared to be fresh oil on the surface, but no other sign of Lieutenant Skaer or the Northrop 3A were ever found.
via Chuck Thompson (X Plane Fans)