FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1928
1928 - 0848.PDF
SEPTEMBER 13, 1928 So much for a resume of earlier work in order to set forth more readily later developments. Aviettes, alulas, or small wings are mounted in front of or above the leading edges of the main wings so as to form a gap between them and the main wings, and means for con- trolling the inclination and projection of the said aviettes, etc., are provided so that either both aviettes can be projected or withdrawn together, or one projected and the other simultaneously retracted. Means for balancing the aviettes are also provided so that they can be operated with a minimum expenditure of energy. The aviettes are arranged to be operated by side motion of the control lever, and they can be projected or retracted together by rotation of a control wheel mounted on the control column. Springs are mounted in the operating mechanism between the control lever and the aviette to enable an aviette on one side of the machine to open up either automatically or when the other aviette is in contact with the front edge of the main plane. In Fig. 6, the aviette or alula is mounted on two pairs of links connected at their lower ends to a projection from the leading edge of the main plane, so that in normal flight the alula may be in closed contact with the nose of the machine and when opened up form a gap which is backwardly inclined upwards. The links may be of any suitable relative length so that the aviette or alula travels in any desired path as the gap is varied. In Figs. 7 and 8 each pair of links are mounted on a lever, the inclination of which may be adjusted from the cockpit so that the inclination of the aviette with the main wing may be varied at will. The aviettes are not necessarily mounted so as to move parallel to the edge. In the arrangements shown in Figs. 9 and 10, the aviette is mounted so as to pivot about one end. Figs. 9 and 10 show another method of mounting aviettes or alulas so that they move parallel to the edge of a main plane. It will be noted that the aviette may be caused to change its inclination simultaneously with motion relative to the wing. The mechanism for doing this may consist of parallel links of definite lengths as shown in Figs. 6, 7 and 8. In the arrangement shown in Fig. 10, the inclination of the aviette or alula is caused to vary with the distance of the aviette from the leading edge by mounting it upon a lever pivoted to projections on the leading edge. The aviettes are controlled by cables from control levers or wheels. Aviettes or alulas may, of course, be fitted to machines having the usual aileron control. When it is desired to take advantage of the higher lift which may be obtained from a wing having aviettes or alulas the aviettes on both sides are projected outwards by the amount, and rotated to the angle, found by experience to give the best results. When it is desired to fly at the highest speed, both aviettes are brought back on top on the main wing so as to offer the minimum resistance, and the necessary' lateral control is Fig. 14. provided either by projecting one aviette at a time, or by the usual aileron control. The springs in the control cables allow this to be done. When the machine is approaching the stalling angle, the aviettes work under different conditions owing to the difference in the air flow over the main plane, and the springs in the control cables permit them to open out automatically on the side which is stalling. The angle of the main plane at which they automatically tend to open may be varied by altering the inclination of a lever. Provision is made for connecting the aileron and aviette controls together either manually or automatically when the machine approaches the stalling angle, also aviettes are provided to the front edges of tail planes or elevators and fins or rudder, as shown in Figs. 11, 12, 13 and 14. Figs. 11, 12 and 13. 784
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
