BA-137-2S

Function of BA-137-2S in engine icing detection

The main function of BA-137-2S is to receive an icing signal from the engine icing detector and issue the required control commands. When the detector identifies icing conditions, the signal is transmitted to the automatic unit. The BA-137-2S then activates the corresponding cockpit warning indication and controls the heating circuit of the detector. This allows the crew and onboard system to detect ice formation in the engine inlet area and maintain detector operability during icing conditions.

Operation with DO-206 icing detector

BA-137-2S works together with DO-206 type icing detectors installed near the engine inlet guide vane area. In the source context, when the inlet openings of the DO-206 detector are blocked by ice, an internal contact closes and sends an electrical signal to the BA-137 unit. The control unit processes this signal and switches the related warning and heating circuits. After ice is removed and detector contacts open, the unit keeps the warning and heating circuits active for a short delay period before switching them off.

Warning and heater control logic

The BA-137-2S unit controls two main output functions: cockpit icing warning and detector heater supply. When an icing condition is detected, the unit issues power to the cockpit warning annunciator for inlet guide vane icing and also supplies power to the heating element of the DO-206 detector. The heating element helps cyclically clear the detector pin or sensing area from accumulated ice. According to the source context, after the detector contact opens, the unit switches off the heater and warning indication with a fixed delay.

Electrical and construction features of BA-137-2S

BA-137-2S operates from the standard aircraft 27 V DC network. The supplied context gives an operating voltage range of 18 to 30 V DC and self-consumption not exceeding 0.5 A, excluding switched heater load. The unit is housed in a metal protective casing with aviation-type plug connector for integration into the anti-icing system wiring. The block is described as vibration-resistant and suitable for aircraft operating conditions, including temperature variation, engine-related vibration and installation in heated or unheated aircraft compartments.

Identification and ordering of BA-137-2S

Before ordering BA-137-2S, the buyer should confirm the aircraft type, engine type, anti-icing system configuration, associated icing detector and required series. The unit may be required for engine anti-icing system repair, replacement of a defective automation block, stock replenishment or restoration of Il-76 / D-30KP equipment. It is important to confirm whether the request concerns BA-137-2S specifically or another BA-137 modification of the second or third series. Product passport, test records, wiring data and connector condition should be checked before shipment.