The RC Allen RCA82A-11 is a 3-inch electric turn coordinator instrument used in aircraft flight decks to indicate both rate of turn (yaw) and roll coordination. It contains an electrically driven gyroscopic system mounted in a tilted gimbal, allowing it to sense aircraft movement in two axes and display coordinated turns via a miniature aircraft symbol.

This model operates on a wide input range of 11–30 VDC, making it compatible with both 14V and 28V aircraft electrical systems. The “-11” version is unlit, meaning it does not include internal instrument panel lighting, unlike the RCA83A variant.

The instrument includes a power failure warning flag, which becomes visible when electrical supply drops below operational limits, ensuring the pilot is aware of gyro failure or insufficient voltage. It is commonly used in general aviation aircraft as part of the standard “turn coordinator” flight instrument set.

Key features include:

RC Allen part number: RCA82A-11
3-inch panel-mounted turn coordinator
Electrical gyro with dual-axis sensing (roll + yaw)
Input voltage: 11–30 VDC (14V / 28V compatible)
Unlit configuration (no internal lighting)
Power failure warning flag indicator
Standard 2-minute turn indication system
Compatible with MS3106A-10SL-3S connector
FAA TSO-certified instrument (meets aviation requirements)
Approx. 1.9 lb (0.86 kg) weight
Used in light aircraft attitude and coordination indication systems