Aerodynamic efficiency refers to the ratio of the lift produced by an aircraft to the drag it experiences. It is a measure of how well an aircraft is able to use its shape and design to minimize drag and maximize lift, allowing it to fly more efficiently.
A higher aerodynamic efficiency means an aircraft can fly faster, farther, and with better fuel efficiency. It also allows for better maneuverability and stability in flight.
The shape and design of the aircraft, including the airfoil shape of the wings, the placement of control surfaces, and the overall streamline design, all play a role in aerodynamic efficiency. Other factors such as air density, airspeed, and angle of attack also impact the efficiency of an aircraft.
Static longitudinal stability refers to an aircraft's ability to maintain a consistent pitch attitude during flight. This means that when the aircraft is disturbed from its original pitch, it will naturally return to its original position without any additional input from the pilot.
Static longitudinal stability is achieved through careful design of the aircraft's center of gravity, wing placement, and tail design. These factors work together to create a stable equilibrium that allows the aircraft to maintain a consistent pitch attitude. Flight control systems also play a role in maintaining longitudinal stability by providing automatic adjustments to keep the aircraft in balance.