PLTW Aerospace Latest Update Graded A+

PLTW Aerospace Latest Update Graded A+ Axial Stress A force with its resultant passing through the centroid of a particular section and being perpendicular to the plane of the section. A force in a direction parallel to the long axis of the structure. Bearing The horizontal direction to or from any point, usually measured clockwise from true north, magnetic north, or some other reference point through 360 degrees. Blind Spot The small circular area in the retina where the optic nerve enters the eye that is devoid of rods and cones and is insensitive to light. Boundary Layer A thin layer of air next to the surface of an airfoil which shows a reduction in speed due to the air's viscosity. Center of Gravity The common reference point for the three axes of the aircraft. Center of Pressure The point on the surface of an object about which the object's surface area is centered. Centroid The geometric center of an area. Cockpit The space in the fuselage of a small airplane containing seats for the pilot, copilot, and sometimes passengers. Composite A material made of multiple layers of fibers held together with a matrix. Compression When a material is reduced in volume by the application of pressure; the reciprocal of the bulk modulus. Compression Stroke The piston moves back towards the cylinder head. Cone Any of the conical photosensitive receptor cells of the vertebrate retina that functions in color vision. Controllability The capability of an aircraft to respond to your flight inputs, especially with regard to attitude and flight path.