Normal operation is confirmed by the absence of the red OFF flag on the display face. For the -3B, there is no Tach Output signal — the flag is the sole indicator of operational status.
No. The 1394T101-3B requires no periodic scheduled maintenance or calibration for continued airworthiness. If the unit fails to perform to specifications, it must be returned to Mid-Continent Instruments and Avionics or their authorized designee for service. There are no field-repairable parts.
Yes. Per SIL 1394T101-01 (effective April 1, 2025), the 1394T101-3B supersedes the 1394T100-3B and is a form, fit, and function equivalent. The SIL may be used to demonstrate that the new part number can be used in lieu of the discontinued part number.
The 1394T101-3B uses a 3-pin MIL-DTL-5051 connector. The mating connector is MS3106A10SL-3S.
The 1394T101 series carries updated certification to FAA/EASA TSO-C3e (vs. TSO-C3b on the 1394T100) and is software qualified to RTCA DO-178C Design Assurance Level A. Additionally, the 1394T101 series contains no moving parts other than the displayed indication and operates silently — whereas the 1394T100 series produced audible sound from its gyro rotor.