US 1971 'Airmail' Silhouette of Delta Winged Plane 9c. Scott. C77


US 1971 'Airmail' Silhouette of Delta Winged Plane 9c. Scott. C77


Series: Airmail 1968-1973

Stamp details: Silhouette of Delta Winged Plane

Issued date: 15-05-1971 (dd/mm/yyyy)
Face value: 9c.

Emission: Air Post

Catalogue No:-
Scott (USA): C77
Stanley Gibbons (UK): A1422
Michel (Germany): 1035
Yvert et Tellier (France): PA75

Printer: Bureau of Engraving and Printing
Print Method: Rotary press

Stamp Colors: Red
Perforation: Perf 10½ x 11¼
Paper: Tagged

Themes: Aircraft, Aviation

Description:- A delta wing is a wing shaped in the form of a triangle. It is named for its similarity in shape to the Greek uppercase letter delta (?). Although long studied, it did not find significant applications until the Jet Age, when it proved suitable for high-speed subsonic and supersonic flight. At the other end of the speed scale, the Rogallo flexible wing proved a practical design for the hang glider and other ultralight aircraft. The delta wing form has unique aerodynamic characteristics and structural advantages. Many design variations have evolved over the years, with and without additional stabilising surfaces.
Source: en.wikipedia.org/wiki/Delta_wing