Bombardier G604-326101-1 Calibrated Proximity Sensor Target

The Bombardier G604-326101-1 is a calibrated proximity sensor target – a specialized GSE maintenance tool used during landing gear system testing and verification on select Bombardier business jets. It is employed to confirm that a proximity sensor correctly registers the presence of a metal target, verifying the sensor's "detected" response during maintenance procedures. The G604-326101-1 is used in conjunction with its companion anti-target tool (G604-326102-25), and together they provide a complete functional check of the proximity sensor system.

The G604-326101-1 is compatible with the Bombardier Global Express, Global Express XRS, Global 5000, Global 5500, Global 6000, Global 6500, Challenger 604, and Challenger 605. These aircraft represent Bombardier's large-cabin business jet lineup, all of which utilize proximity sensors as a critical element of their landing gear position monitoring and control systems. For maintenance operations that service multiple Bombardier platforms, the G604-326101-1 is a versatile and broadly applicable tool.

During landing gear maintenance, the G604-326101-1 is presented to the proximity sensor to simulate the presence of a metal target – replicating the "detected" condition without requiring actual gear movement. The technician verifies that the sensor produces the correct output response at the landing gear electronic control unit (LG ECU), confirming the sensor activates at the proper detection threshold. This allows precise verification of sensor performance under controlled conditions, independent of the mechanical state of the landing gear assembly.

The G604-326101-1 and G604-326102-25 are companion tools that test opposite ends of a proximity sensor's operating range – the target verifies the sensor's response when a metal component is detected, while the anti-target verifies its response when no target is present. In landing gear applications, these two conditions correspond to the gear being in position versus out of position, and a properly functioning sensor must respond accurately to both. Using only one tool without the other would leave half of the sensor's functional range unverified, which is insufficient for a complete and defensible maintenance record.

A proximity sensor that fails to detect a target when one is present – or that falsely detects a target when none exists – can produce incorrect gear position indications in the cockpit, potentially compromising flight safety. Testing both the triggered and non-triggered states ensures the sensor is functioning accurately across its full operating range, not just in one direction. Bombardier's maintenance procedures require both the G604-326101-1 target and G604-326102-25 anti-target for this reason, as a complete functional check demands verification of both sensor states.

The G604-326101-1 is a ground support equipment (GSE) maintenance tool – it is not installed on the aircraft. It is held in the shop's tooling inventory and brought out during scheduled maintenance events that require landing gear proximity sensor verification. Bombardier designates it as tooling in its official service documentation, and it should be maintained, calibrated, and stored in accordance with the applicable Bombardier Illustrated Tool and Equipment Manual (ITEM).