BACKCOURSE APPROACH
Approach with back course, the approach to the runway in the opposite direction of the conventional approach. When landing with a return rate of glide path beacon signals are not available, and the perception localizer signal must be the opposite (reverse).
BACKGROUND DATA
DATA background, the data shown on the EFIS (electronic flight instruments) which do not change the appearance of the instrument, such as navigational aids.
BAFFLE
Baffles partition in the tank or vessel to prevent movement of fluid in said tank or reservoir.
BALANCE TAB
BALANCING COMBINATION, small pinchers and the movable part in the moving edge control surfaces (aileron, elevator, rudder). A guard moves in the opposite direction to the control surfaces to assist in moving the control surfaces.