Aviation Maintenance Terms beginning with B

B/CU

Battery/Charger Unit

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BAT or BATT

Battery

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BCD

Binary-coded Decimal

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BDC

Bottom dead center. The position of a piston in a reciprocating engine when the piston is at the bottom of its stroke, and the wrist pin, crankpin, and center of the crankshaft are all in line.

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BHP

Brake horsepower. The actual horsepower delivered to the propeller shaft of a reciprocating or turboprop engine.

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BIT

Binary Digit; Built-in Test

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BITE

Built-in test equipment.

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BITE

Built-in test equipment. A troubleshooting system installed in many modern electronic equipment. BITE equipment monitors engine and airframe systems, and when a fault is found, isolates it and provides maintenance personnel with a code that identifies the LRU (line replaceable unit) that contains the fault.

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BITE

Built-in Test Equipment

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BITS

Bus Interconnect Transfer Switch

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BMEP

Brake mean effective pressure. The average pressure inside the cylinder of a reciprocating engine during the power stroke. BMEP, measured in pounds per square inch, relates to the torque produced by the engine and can be calculated when you know the brake horsepower.

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BNR

Binary Numerical Reference; Binary

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BP

Band-Pass

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BPCU

Bus Power Control Unit

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BSFC

Brake specific fuel consumption. A measure of the amount of fuel used for a given amount of power produced by a heat engine. BSFC is expressed in pounds of fuel burned per hour for each brake horse-power the engine is producing.

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BT

Bus Tie

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BTB

Bus Tie Breaker

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BTC

Before Top Center

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BUS

Electrical Bus; 429 Digital Data Bus

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