Glossary

Spatial disorientation. The state of confusion due to Stability. The inherent quality of an airplane to correct for misleading information being sent to the brain from various conditions that may disturb its equilibrium, and to return sensory organs, resulting in a lack of awareness of the aircraft or to continue on the original flight path. It is primarily an position in relation to a specific reference point. airplane design characteristic. Special flight permit. A flight permit issued to an aircraft Stagnant hypoxia. A type of hypoxia that results when the that does not meet airworthiness requirements but is capable oxygen-rich blood in the lungs is not moving to the tissues of safe flight. A special flight permit can be issued to move that need it. an aircraft for the purposes of maintenance or repair, buyer delivery, manufacturer flight tests, evacuation from danger, Stall. A rapid decrease in lift caused by the separation of or customer demonstration. Also referred to as a ferry permit. airflow from the wing’s surface, brought on by exceeding the critical angle of attack. A stall can occur at any pitch Special use airspace. Airspace in which flight activities are attitude or airspeed. subject to restrictions that can create limitations on the mixed use of airspace. Consists of prohibited, restricted, warning, Standard atmosphere. At sea level, the standard atmosphere military operations, and alert areas. consists of a barometric pressure of 29.92 inches of mercury ("Hg) or 1013.2 millibars, and a temperature of 15 °C (59 Special fuel consumption. The amount of fuel in pounds °F). Pressure and temperature normally decrease as altitude per hour consumed or required by an engine per brake increases. The standard lapse rate in the lower atmosphere for horsepower or per pound of thrust. each 1,000 feet of altitude is approximately 1 "Hg and 2 °C (3.5 °F). For example, the standard pressure and temperature Speed. The distance traveled in a given time. at 3,000 feet mean sea level (MSL) are 26.92 "Hg (29.92 "Hg – 3 "Hg) and 9 °C (15 °C – 6 °C). Spin. An aggravated stall that results in an airplane descending in a helical, or corkscrew path. Standard empty weight (GAMA). This weight consists of the airframe, engines, and all items of operating equipment Spiral instability. A condition that exists when the static that have fixed locations and are permanently installed in the directional stability of the airplane is very strong as compared airplane including fixed ballast, hydraulic fluid, unusable to the effect of its dihedral in maintaining lateral equilibrium. fuel, and full engine oil. Spiraling slipstream. The slipstream of a propeller-driven Standard holding pattern. A holding pattern in which all airplane rotates around the airplane. This slipstream strikes turns are made to the right. the left side of the vertical fin, causing the aircraft to yaw slightly. Rudder offset is sometimes used by aircraft designers Standard instrument departure procedures (SIDS). to counteract this tendency. Published procedures to expedite clearance delivery and to facilitate transition between takeoff and en route operations. Spoilers. High-drag devices that can be raised into the air flowing over an airfoil, reducing lift and increasing drag. Standard rate turn. A turn in which an aircraft changes its Spoilers are used for roll control on some aircraft. Deploying direction at a rate of 3° per second (360° in 2 minutes) for spoilers on both wings at the same time allows the aircraft low- or medium-speed aircraft. For high-speed aircraft, the to descend without gaining speed. Spoilers are also used to standard rate turn is 1½° per second (360° in 4 minutes). shorten the ground roll after landing. Standard service volume (SSV). Defines the limits of the SRM. See single-pilot resource management. volume of airspace which the VOR serves. SSR. See secondary surveillance radar. Standard terminal arrival route (STAR). A preplanned IFR ATC arrival procedure published for pilot use in graphic SSV. See standard service volume. and/or textual form. Stabilator. A single-piece horizontal tail surface on an Standard weights. Weights established for numerous items airplane that pivots around a central hinge point. A stabilator involved in weight and balance computations. These weights serves the purposes of both the horizontal stabilizer and the should not be used if actual weights are available. elevators. G-28