Exploratory study of the operational conditions of a Bell Model 205A-1 helicopter in USFS service

Thesis (M.S.)--Wichita State University, College of Engineering, Dept. of Aerospace Engineering.For this exploratory study, flight data of a Bell Model 205A-1 helicopter, flying under contract to the United States Forest Service, is analyzed to investigate its operational conditions. Usage of the helicopter, specifically the missions performed, and phases occurring within those missions, is determined; as well as finding the magnitude and classification of vertical loads that occurred in the course of operation. As a result, it is determined that the helicopter was required to carry out seven distinguishable types of missions; and within those missions, the helicopter performed ten flight phase types, three of which were mission specific. A program code is written to determine these phases and mission types. Data is presented to show the flight usage of the helicopter for all mission types, as well as the specific phases occurring within those missions. Due to placement of the accelerometers in the nose of the aircraft, separation of gust and maneuver loads is difficult. A method is presented to classify vertical loads into three categories based upon roll and pitch rates of the helicopter. Flight load data is presented to help understand the loading the helicopter experiences through its overall flights along with the maximum and minimum loads experienced in individual flight phases