Civil Tiltrotor: Flight Simulation Development of Instrument Procedures

Bell Helicopter TEXTRON, Inc., Boeing Defense & Space Group, Helicopters Division, and NASA have conducted real-time, piloted simulation research demonstrating the ability of tiltrotor aircraft to execute steep instrument approaches to vertical landings. Approaches with glide slopes as steep as 25° have been successfully demonstrated in simulation. Guidance cues provided for the pilots included raw flightpath deviation data and flight director steering commands. The low speeds associated with the steepest approaches introduce unique problems that favor the use of flight director guidance or modified pilot control strategies. Steep approaches are expected to be a normal requirement for center-city vertiport operations, but existing instrument procedures and air traffic control procedures do not support the steep approach capabilities of vertical flight aircraft. The Federal Aviation Administration has recognized this and directed the development of the Vertical Flight IFR Terminal Area Procedures (VERTAPS) program plan. VERTAPS will develop instrument procedures and air traffic control procedures to take advantage of the unique capabilities of vertical flight aircraft while safely and efficiently integrating them into the national airspace system. A structured combination of simulation and flight test evaluations will be used to develop vertical flight instrument procedures, develop air traffic control procedures, and validate simulation as a tool for instrument procedure development.