How dp planes stay in the air?

The chines themselves were an interesting and unique feature. The Blackbird was originally not going to have chines — it would have looked a little like an enlarged F-104 — but the radar engineers convinced the aerodynamicists to try adding them to a few wind-tunnel models during the design process, as the chines would supposedly reduce the aircraft's Radar Cross Section from many angles. The aerodynamicists discovered that the chines generated powerful vortices around themselves, generating much additional lift near the front of the aircraft. The angle of incidence of the delta wings could then be reduced, allowing for greater stability and less high-speed drag, and more weight (fuel) could be carried, allowing for greater range. Landing speeds were also reduced, since these powerful vortices created turbulent flow over the wings at high angles of attack, making it harder for the wings to stall. (The Blackbird can, consequently, make high-alpha high-G turns to the point where the Blackbird's unique engine air inlets stop ingesting enough air, which can cause the engines to flame out. Blackbird pilots were thus warned not to pull more than 3Gs, so that angles of attack stay low enough for the engines to always get enough air). The chines act like the leading edge extensions which are used to increase the agility of many modern fighters such as the F-5, F-16, F/A-18, MiG-29 and Su-27. Once these advantages were observed during wind-tunnel tests of Blackbird models, the use of canard foreplanes was no longer needed. (Many early design models of what became the Blackbird featured canards.) Chines are still an important part of the design of many of the newest stealth UAVs, such as the Dark Star, Bird of Prey, X-45, and X-47, since they allow for tail-less stability as well as for stealth.