The RC Allen electric directional gyro is similar in appearance and presentation to P/N RCA11A-8 but employs an electrically-driven rotor whose gimbal frame is connected to the vertical azimuth card. A heading select knob is fitted at the 7 o'clock position. Rotor run-up time is 3 min. max. after power is applied. All models have an AC (brushless) motor. The DC versions have a built-in inverter which converts the aircraft DC power to the required voltage & frequency for motor operation. A power failure warning flag drops into view whenever the supply voltage is lost or when the voltage has dropped below a level acceptable for proper operation of the gyro. Connector mates with Amphenol P/N 126-223 or equivalent. Diam: 3-3/8 x 3-3/8 x 6-1/4". Power: 14, 28 VDC. This directional gyro meets or exceeds requirement of FAA TSO-C5c.