degrees Celsius). On 23 June 1948 the system's airborne transmitter rebroadcast the Republican National Convention, being held in Philadelphia, Pennsylvania, to the surrounding nine-state area during the 9 to 10 pm EDT time period. As part of the activity, a receiver was set up in a hall in Zanesville, Ohio, a small city on the outskirts of the broadcast area, to demonstrate to invited newspaper reporters that the system was capable of reaching "small town and farm homes". The tests were watched by many television viewers who sent in reception reports. From these reports it was calculated that Stratovision would require only eight relay planes to provide a transcontinental network, and six additional planes to provide coverage to 78% of the United States. Charles Edward Nobles, the head of Stratovision for Westinghouse, said in his report: "The major technical problems of the system have been solved, and the commercial development awaits only the crystallization of public demand for the expanded services offered by airborne broadcasting, application of the system by the radio industry to meet this demand, and the clarification of channel facilities available to make possible this application." Education In 1961 a nonprofit organization, Midwest Program on Airborne Television Instruction, commenced a Stratovision service from the airfield of Purdue University. The effort began as a three-year experiment funded by the Ford Foundation. The program organized, produced and transmitted educational television programs four days a week from a DC-6AB aircraft flying at over the community of Montpelier in north central Indiana. MPATI delivered its programs to television channels 72 (call sign KS2XGA) and 76 (KS2XGD) in the UHF band, by transmitting videotaped lectures from the aircraft to an estimated potential 5,000,000 students in 13,000 schools and colleges. The aircraft were equipped with two videotape machines and two UHF transmitters. When MPATI signed on it used an "Indian head" test pattern card which was shown for five minutes before and between programs. The service ended in 1968 when it became embroiled in legal action over their application of Stratovision in a controversy with the Westinghouse company. Propaganda Vietnam War During the Vietnam War, the United States Navy used Stratovision television technology when it flew Operation Blue Eagle from 1966 to 1972 over the Saigon area of South Vietnam. The television programs were aimed at two audiences on two channels: one was aimed at the general public and the other was intended