The original P-38 design was to meet an Army Air Corps requirement fora point defense fighter to defend cities and other potential targets from bombers. The criteria was time to climb to intercept and putting enough weight of metal of guns in the right place to shoot down a bomber. As it was not thought many would be needed (maybe a couple hundred at most) the YP-38 was designed to be essentially hand built. The YP was flown from Burbank to set a cross country speed record (which it did) but landed on a golf course in New York and was totaled (pilot walked away). The Air Corps said "great" upped the order quantity to a whole whole bunch and set Lockheed production back a year or two.