TER-1M

Automatic glass heating control through TER-1M

The TER-1M monitors the temperature condition of the heated glass through a connected resistance temperature sensor. When the glass temperature changes, the sensor resistance changes accordingly. The regulator processes this resistance value and, when the threshold is reached, sends a control signal to the magnetic contactor. The contactor then switches the heating circuit. This allows the system to maintain windshield temperature within the required range without constant manual switching by the crew. Stable operation of the regulator helps preserve visibility and reduce thermal stress on the glass.

TER-1M with TD-2 temperature sensor

The TER-1M operates together with a wire-type temperature sensor, such as TD-2, installed directly on the heated glass surface. The TD-2 sensor provides the temperature-dependent resistance input used by the regulator. The regulator does not heat the glass by itself; it controls the electrical switching of the heating circuit through associated contactors. Because the regulator depends on sensor accuracy and wiring condition, troubleshooting should include the TER-1M unit, TD-2 sensor, connector contacts, wiring harness, magnetic contactor and heating element circuit.

Installation of TER-1M in Mi-8 / Mi-17 cockpit equipment

On Mi-8 / Mi-17 type helicopters, TER-1M regulators are installed in the cockpit area, normally on equipment shelves behind the pilots’ seats, in the area of fuselage frames 4N–5N. Two regulators may be installed for the left and right heated cockpit glass panels. They operate as part of the windshield anti-icing system together with magnetic contactors and related electrical equipment, including the AT-8-3 autotransformer where applicable. Installation inside the cockpit protects the electronic unit from direct external environmental exposure and allows replacement during maintenance.

Construction and electrical integration of TER-1M

The TER-1M is a compact monoblock device in a screened metal housing with an aircraft electrical connector. It is integrated into the aircraft 27 V DC onboard electrical system and controls the heating circuit through associated switching devices. The unit is intended for operation in aircraft electrical equipment compartments and cockpit-mounted avionics areas. Its connector-based installation allows the regulator to be removed and replaced during service. During inspection, technicians normally check housing condition, connector pins, wiring continuity, sensor circuit resistance and contactor response.

Identification and ordering of TER-1M

Before ordering TER-1M, the aircraft type, glass heating circuit, sensor type, required condition and documentation set should be confirmed. If the unit is required for a Mi-8 / Mi-17 windshield heating system, it is useful to specify whether it is for the left or right heated glass circuit and whether the associated TD-2 sensor, magnetic contactor or AT-8-3 equipment is also required. For acceptance, the buyer should clarify the availability of product passport, test records, connector configuration and serviceability documentation.