MIL-HDBK-143A
boattail - The conical section of a ballistic body that progressively decreases in diameter
toward the tail to reduce overall aerodynamic drag.
body mounted Gyroscope - A Gyroscope mounted directly on the body of a missile airframe;
used as a reference instead of a stabilized platform.
BODY SECTION, GUIDED MISSILE - That which makes up a portion of a Guided Missile
body, and, when used in conjunction with other missile body sections, forms a complete
missile. It provides the housing and may contain ard/or have accommodations for attaching
mechanical, electronic, and high explosive components.
boil-off - The vapor loss from any volatile liquid, e.g., LIQUID OXYGEN, particularly when
stored in a missile ready for flight.
booster - An auxiliary or initial propulsion system which travels with a missile and may or
may not be separated from the missile when its impulse his been delivered. A booster system
may contain or consist of one or more units.
boost-glide vehicle - An air-breathing vehicle capable of aerodynamic lift, which is propelled
to extreme altitudes by reaction propulsion arid returns with little or no power or guidance. it
uses glide principles to increase effective range on re-entry.
boot-strap operation - A self-generating or self-sustaining process which is, in liquid
ROCKET ENGINE operation, the feeding back of a portion of the turbo-pump output to a gas
generator which causes an increase in available energy for driving the turbo-pump, which in
turn delivers more Propellant to the gas generator.
boundary layer - The thin region of nearly static fluid next to the surface over which the fluid
stream is moving. In the case of a missile traveling in the atmosphere, the stagnant layer of
air along the surface of the airframe or aerodynamic control surfaces.
burner drag - The total drag created by a missile propulsion system; includes the drag forces
on the igniter, flame holders, diffuser wall, combustion chamber wall, etc.
burnout - The point in time or in the missile trajectory when combustion of fuels in the
ROCKET ENGINE is terminated by other than programmed cutoff.
C
canard configuration - A missile airframe which has the horizontal Surfaces used for trim and
control on the forward horizontal portion of the body, and the main lifting surfaces attached to
the rear section. The forward control surfaces can be used to vary lift by varying the angle of
attack of the body-wing combination Cf: dart configuration
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