Today’s large transport aircraft all share a common tail design with aft body-mounted horizontal stabilizers and a vertical fin. After gradual development over decades, this concept has now reached a degree a maturity that leaves only limited room for further improvements. To
explore the possibilities of unconventional tail designs on civil aircraft, the EU funded research programme ”New Empennage for Aircraft” (NEFA) was conducted, comprising structural-, flight mechanics and aerodynamic aspects.
NEFA aims at assessing V-empennage type on aircraft in order to validate promising preliminary results.
Aerodynamic performance prediction capability have been improved thanks to co-operative use of CFD tools and wind-tunnel tests at low speed with high-lift devices and at transonic speed. Flight mechanics of V-aircraft have been studied with analytical tools derived from those used for conventional empennage aircraft. Flight control laws have been defined and validated in a flight simulator (fixed base). Structural concepts for installation of V-empennage on rear fuselage have been defined and assessed.
Finally all models for aerodynamics coefficients and weights assessment have been used along with the drivers for stability and control in order to carry out an homogeneous comparison between conventional tail aircraft and V-tail aircraft.
Within the NEFA project, multidisciplinary investigations on the feasibility of H-, U- and V-tail designs for a generic twin-jet transport aircraft were carried out. In terms of increased aerodynamic efficiency and reduced production costs, the V-tailed aircraft was found most promising. Such a configuration offers the advantage to provide lateral and longitudinal stability by only two stabilizer surfaces, instead of three. Possible aerodynamic benefits are reduced interference drag and a slightly smaller wetted tail surface area. Also the reduced number of tail surfaces leads reduced production costs compared to conventional designs.
- Knowledge of the V-tailhas been gained in aerodynamics, handling qualities and structure
- V-aircraft design capabilities have been developed
- Obviously the state of the art is not as high as the one for conventional empennage
- Grey areas for further research have been identified