1929 Travel Air 4-D, Pilot: Bruce McElhoe. Travel Air 89K was manufactured by the Travel Air Manufacturing Co. in Wichita, Kansas in September, 1929. The factory produced 17 model 4-DÕs before stopping production a few months later as the depression deepened. This is the only original Model 4-D still flying in the world today and won Grand Champion in Pasa Robles just this year.