What is trimmed flight?
In flight, during maneuvers, an airplane rotates about its cg. But when the aircraft is not maneuvering, we want the rotation about the cg to be zero. When there is no rotation about the cg the aircraft is said to be trimmed.
What makes a plane unstable?
Shifting it past the neutral point makes the airplane unstable, so movements away from the trimmed state are accelerated. This increases maneuverability. Flight computers are multiple redundant, if one dies the others take over. Slow unstable airplanes can be flown by a human pilot, but not fast unstable airplanes.
What controls trim on a plane?
Once the airplane is stable, whether in climb, descent, or level flight, the pilot “trims” the aircraft by moving a smaller control surface on the elevator’s trailing edge — the trim tab — in the opposite direction from the elevator itself (diagram at right).
Why do they install several TR’s in the airplane?
Multiple layers of redundancy greatly reduce the potential for loss of all electrical generation capability. Components connected to the bus have individual circuit protection which, in the event of a component failure protect the bus from overload and thus protect the remaining components.
What is the most aerodynamic plane in the world?
The December 14, 1984, test flight of the X-29—the most aerodynamically unstable aircraft ever built—demonstrated forward-swept wing technology for supersonic fighter aircraft for the first time.
When does an airplane need to be trimmed?
When there is no rotation about the cg the aircraft is said to be trimmed. On most aircraft, the center of gravity of the airplane is located near the center of pressure of the wing. If the center of presure of the wing is aft of the center of gravity, its lift produces a counter-clockwise rotation about the cg.
Why do you trim the tail of an aircraft?
To trim the aircraft it is necessary to balance the torques produced by the wing and the tail. But since both rotations are counter-clockwise, it is impossible to balance the two rotations to produce no rotation. However, if the tail lift is negative it then produces a clockwise rotation about the cg which can balance the wing rotation.
How is the stability of an aircraft determined?
Stability is a measure not simply of how well an aircraft responds to disturbances – it also denotes how difficult the aircraft will be to manoeuvre. For this reason, the same stability characteristics are not found in airliners and fighter aircraft.
How are two torques equal in trimmed flight?
In trimmed flight, these two torques are equal: The torque equation, as written here, is a vector equation . All of the quantities are vector quantities having a magnitude and a direction.