The Aeroplane Speaks [55]
of an engine is a measure of the rate at which work is done by the pressure upon the piston or pistons, as distinct from the rate at which the engine does work. The latter is usually termed ``brake horse-power,'' since it may be measured by an absorption brake.
Power, Margin of--The available quantity of power above that necessary to maintain horizontal flight at the optimum angle.
Pitot Tube--A form of air-speed indicator consisting of a tube with open end facing the wind, which, combined with a static pressure or suction tube, is used in conjunction with a gauge for measuring air pressures or velocities. (No. 1 in diagram.)
Pitch, Propeller--The distance a propeller advances during one revolution supposing the air to be solid.
Pitch, to--To plunge nose-down.
Reaction--A force, equal and opposite to the force of the action producing it.
Rudder--A controlling surface, usually hinged to the tail, the operation of which turns an aeroplane about an axis which is vertical in normal horizontal flight; causes an aeroplane to turn to left or right of the pilot.
Roll, to--To turn about the longitudinal axis.
Rib, Ordinary--A light curved wooden part mounted in a fore and aft direction within a surface. The ordinary ribs give the surface its camber, carry the fabric, and transfer the lift from the fabric to the spars.
Rib, Compression--Acts as an ordinary rib, besides bearing the stress of compression produced by the tension of the internal bracing wires.
Rib, False--A subsidiary rib, usually used to improve the camber of the front part of the surface.
Right and Left Hand--Always used relative to the position of the pilot. When observing an aeroplane from the front of it, the right hand side of it is then on the left hand of the observer.
Remou--A local movement or condition of the air which may cause displacement of an aeroplane.
Rudder-Bar--A control lever moved by the pilot's feet, and operating the rudder.
Surface--See ``Aerofoil.''
Surface, Detrimental--All exterior parts of an aeroplane including the propeller, but excluding the (aeroplane) lifting and (propeller) thrusting surfaces.
Surface, Controlling--A surface the operation of which turns an aeroplane about one of its axes.
Skin-Friction--The friction of the air with roughness of surface. A form of drift.
Span---The distance from wing-tip to wing-tip.
Stagger--The distance the upper surface is forward of the lower surface when the axis of the propeller is horizontal.
Stability--The inherent tendency of a body, when disturbed, to return to its normal position.
Stability, Directional--The stability about an axis which is vertical during normal horizontal flight, and without which an aeroplane has no natural tendency to remain upon its course.
Stability, Longitudinal--The stability of an aeroplane about an axis transverse to the direction of normal horizontal flight, and without which it has no tendency to oppose pitching and tossing.
Stability, Lateral--The stability of an aeroplane about its longitudinal axis, and without which it has no tendency to oppose sideways rolling.
Stabilizer--A surface, such as fin or tail-plane, designed to give an aeroplane inherent stability.
Stall, to--To give or allow an aeroplane an angle of incidence greater than the ``maximum'' angle, the result being a fall in the lift- drift ratio, the lift consequently becoming less than the weight of the aeroplane, which must then fall, i.e., ``stall'' or ``pancake.''
Stress--Burden or load.
Strain--Deformation produced by stress.
Side-Slip, to--To fall as a result of an excessive ``bank'' or ``roll.''
Skid, to--To be carried sideways by centrifugal force when turning to left or right.
Skid, Undercarriage--A spar, mounted in a fore and aft direction, and to which the wheels of the undercarriage are sometimes attached. Should a wheel give way the skid is then supposed to act like the runner of a sleigh and to support the aeroplane.
Skid, Tail--A piece of wood or other material, orientable, and fitted with shock
Power, Margin of--The available quantity of power above that necessary to maintain horizontal flight at the optimum angle.
Pitot Tube--A form of air-speed indicator consisting of a tube with open end facing the wind, which, combined with a static pressure or suction tube, is used in conjunction with a gauge for measuring air pressures or velocities. (No. 1 in diagram.)
Pitch, Propeller--The distance a propeller advances during one revolution supposing the air to be solid.
Pitch, to--To plunge nose-down.
Reaction--A force, equal and opposite to the force of the action producing it.
Rudder--A controlling surface, usually hinged to the tail, the operation of which turns an aeroplane about an axis which is vertical in normal horizontal flight; causes an aeroplane to turn to left or right of the pilot.
Roll, to--To turn about the longitudinal axis.
Rib, Ordinary--A light curved wooden part mounted in a fore and aft direction within a surface. The ordinary ribs give the surface its camber, carry the fabric, and transfer the lift from the fabric to the spars.
Rib, Compression--Acts as an ordinary rib, besides bearing the stress of compression produced by the tension of the internal bracing wires.
Rib, False--A subsidiary rib, usually used to improve the camber of the front part of the surface.
Right and Left Hand--Always used relative to the position of the pilot. When observing an aeroplane from the front of it, the right hand side of it is then on the left hand of the observer.
Remou--A local movement or condition of the air which may cause displacement of an aeroplane.
Rudder-Bar--A control lever moved by the pilot's feet, and operating the rudder.
Surface--See ``Aerofoil.''
Surface, Detrimental--All exterior parts of an aeroplane including the propeller, but excluding the (aeroplane) lifting and (propeller) thrusting surfaces.
Surface, Controlling--A surface the operation of which turns an aeroplane about one of its axes.
Skin-Friction--The friction of the air with roughness of surface. A form of drift.
Span---The distance from wing-tip to wing-tip.
Stagger--The distance the upper surface is forward of the lower surface when the axis of the propeller is horizontal.
Stability--The inherent tendency of a body, when disturbed, to return to its normal position.
Stability, Directional--The stability about an axis which is vertical during normal horizontal flight, and without which an aeroplane has no natural tendency to remain upon its course.
Stability, Longitudinal--The stability of an aeroplane about an axis transverse to the direction of normal horizontal flight, and without which it has no tendency to oppose pitching and tossing.
Stability, Lateral--The stability of an aeroplane about its longitudinal axis, and without which it has no tendency to oppose sideways rolling.
Stabilizer--A surface, such as fin or tail-plane, designed to give an aeroplane inherent stability.
Stall, to--To give or allow an aeroplane an angle of incidence greater than the ``maximum'' angle, the result being a fall in the lift- drift ratio, the lift consequently becoming less than the weight of the aeroplane, which must then fall, i.e., ``stall'' or ``pancake.''
Stress--Burden or load.
Strain--Deformation produced by stress.
Side-Slip, to--To fall as a result of an excessive ``bank'' or ``roll.''
Skid, to--To be carried sideways by centrifugal force when turning to left or right.
Skid, Undercarriage--A spar, mounted in a fore and aft direction, and to which the wheels of the undercarriage are sometimes attached. Should a wheel give way the skid is then supposed to act like the runner of a sleigh and to support the aeroplane.
Skid, Tail--A piece of wood or other material, orientable, and fitted with shock