BETWEEN THE IMPLEMENTATION of the Air Commerce Act of 1926 and December 31, 1948, all U.S. registered flying machines sported an N-number, much as they do today, the “N” being an internationally recognized identifier for the United States. During that period, however, an additional letter-identifier followed the “N.” Depending on their category, they were registered in the NC (Commercial), NG (Glider), NL (Limited), NR (Restricted, usually meaning race airplanes), NS (State government), and, finally, NX (eXperimental).
Airplanes registered in the NC category are seldom seen today, but the others, including NS (State) registrations, are all but unknown. One of those “S” category rarities is Dave and Jeanne Allen’s WACO YKC N14137 (c/n 4223). A superb piece of work, it has even won the Antique Grand Champion award at EAA’s AirVenture.…