The letter from the Federal Aviation Agency to Senator Monroney discusses changes in the flight path in the sonic boom study program in Oklahoma City. The agency explains that they have been flying specific flight tracks to study the effects of sonic booms on test houses, and that no damage has occurred so far. They received a suggestion to change the flight path and conducted additional flights in different directions to gather more data. The agency assures the Senator that they are willing to provide further information and assistance if needed.