Bombardier G604-326102-25 Calibrated Proximity Sensor Anti-Target

The Bombardier G604-326102-25 is a calibrated proximity sensor anti-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 absence of a metal target, verifying the sensor's "not detected" response during maintenance procedures. The G604-326102-25 is used in conjunction with its companion target tool (G604-326101-1), and together they provide a complete functional check of the proximity sensor system.

The G604-326102-25 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 span Bombardier's flagship large-cabin business jet families, all of which share common landing gear system architecture that relies on proximity sensors for gear position monitoring and control. Technicians working across multiple Bombardier platforms will find the G604-326102-25 a broadly applicable tool for their landing gear maintenance programs.

In proximity sensor terminology, a "target" is the metal component whose presence the sensor is designed to detect – when the target is near the sensor, the sensor triggers and signals that the monitored component (such as a landing gear assembly) is in position. An "anti-target" is its complement: a calibration tool engineered to present a non-triggering condition, allowing technicians to verify that the sensor correctly registers the absence of a target. Testing both states – triggered and not triggered – is essential to confirming that the sensor will respond accurately across its full operating range during flight operations.

During landing gear system maintenance on compatible Bombardier aircraft, the G604-326102-25 is used to simulate the condition where no metal target is present near the proximity sensor – replicating the "not detected" state without requiring actual gear movement. The technician presents the anti-target to the sensor and verifies the correct output response from the landing gear electronic control unit (LG ECU), confirming the sensor is properly calibrated and functioning within specification. This procedure is referenced under ATA Chapter 32 (Landing Gear) in Bombardier's service documentation and is performed as part of standard operational testing following maintenance events.

The companion tool to the G604-326102-25 anti-target is the G604-326101-1 calibrated proximity sensor target. While the anti-target verifies that the sensor correctly responds when no target is detected, the target verifies the sensor's response when a metal component is present – together, they provide a complete end-to-end functional check of the proximity sensor. Performing both halves of the test is necessary to confirm the sensor is operating accurately at both ends of its detection range, which is critical for the safe and reliable operation of the landing gear system.

The G604-326102-25 is a ground support equipment (GSE) maintenance tool – it is not installed on the aircraft. It is used by maintenance technicians to test and verify proximity sensor performance during scheduled maintenance events and is stored with the shop's tooling inventory between uses. Bombardier lists it as tooling in its official service documentation, alongside other GSE required to complete specific maintenance tasks on the landing gear system.