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Short Takeoff Optimization for the XV-15 Tiltrotor Aircraft

T.M. Cerbe, G. Reichert, D.P. Schrage
Tiltrotor aircraft are being developed for a variety of military and civil operations. Although a tiltrotor aircraft will often make use of vertical takeoff, the short takeoff is of importance for some applications under speci fie conditions, such as high gross weights or unfavorable ambient conditions. Whereas the vertical takeoff is well understood due to its similarity to the vertical takeoff of conventional helicopters, there is a lack of information about how to perform the best short takeoff procedure. The short takeoff performance and the short takeoff distance depend on many variables. Few, if any, studies have investigated the calculation or the optimization of the short takeoff for tiltrotor aircraft. Most often, the estimation of short takeoff performance has been based on the experience gained from XV-15 tiltrotor aircraft flight tests. These flight tests, however, utilized only a fixed nacelle tilt angle and a fixed wing flap deflection. The main objective of this effort was to provide more information about the short takeoff capability of civil tiltrotor aircraft. This information is helpful for the design of new tiltrotor aircraft, the development and construction of new vertiports, and the specification of One-Engine-Inoperative (OEI) requirements. In addition, the FAA could use additional short takeoff data to review the new criteria for civil tiltrotor aircraft. Since the short takeoff depends on many variables, such as gross weight, ambient conditions, power available, flap setting, nacelle tilt, and maneuver strategy, takeoff related performance is analyzed by varying different parameters. The takeoff distance is minimized using the optimization methods developed at the Technical University of Braunschweig. The takeoff simulation is carried out using the Generic Tilt Rotor Simulation (GTRS). The XV-15 geometric and aerodynamic data sets are used. Because GTRS has never been consistently correlated with XV-15 flight test data for the low. Speed flight region OGE and IGE, which is relevant for the short takeoff, the aerodynamic modeling for horizontal speeds less than 60 knots must be proven. Therefore, a further objective of this effort was to develop a more reliable simulation model. The results of this investigation will be presented as well as the recommended changes to the GTRS model necessary for short takeoff optimization for tiltrotor aircraft.
17th European Rotorcraft Forum 1991, Berlin
Conference Paper
21,0 x 29,7 cm, 20 Seiten
DGLR-Bericht, 1991, 1991-08, 17th European Rotorcraft Forum Proceedings; S.213-232; 1991; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn
Stichworte zum Inhalt:
tilt rotor aircraft, bell xv-15 tiltrotor aircraft

Dieses Dokument ist Teil einer übergeordneten Publikation022:
17th European Rotorcraft Forum Proceedings