Nav-Aids 18821-4 Pitot Test Adapter

The Nav-Aids 18821-4 pitot test adapter creates a sealed connection between the aircraft’s pitot probe and an air data test set, enabling accurate pitot system checks without leakage or measurement errors. Once installed, it allows technicians to test each pitot system independently or simultaneously, depending on the aircraft configuration. This helps verify proper airspeed indication, pitot pressure response, and system integrity during scheduled maintenance.

The 18821-4 is used across multiple Nav-Aids air data kits, including those for the Gulfstream G150/G200, Dornier 228, Bombardier CL-215, Mooney aircraft, as well as the AH-64D and CH-136 helicopters. Each platform uses the adapter with the pitot probe type specified in its kit documentation. Compatibility depends on the probe model – such as AN5812, PH502, or P/R-603/2/5 – ensuring a secure, leak-free fit during testing.

The number of adapters required corresponds to the number of independent pitot systems needing isolation during testing. Twin-pitot aircraft such as the G150, G200, Dornier 228, or AH-64D require two adapters to test each system either separately or simultaneously. Aircraft with a single pitot probe, such as certain Mooney models, only require one adapter.

The adapter provides a sealed mechanical interface that prevents air leakage, ensuring the air data test set can apply stable pressures with a predictable response. This tight seal allows accurate detection of leaks, blockage issues, and calibration errors in the aircraft’s pitot system. Proper adapter use ensures that test results accurately reflect true system performance, rather than connection-induced errors.

Yes. The adapter is engineered for straightforward installation on the specified pitot probe, often requiring only hand pressure and proper alignment. Removal is equally quick and does not require tools, helping minimize aircraft downtime during pitot-static testing cycles. Nav-Aids also includes hose connection guidance in the applicable air data kit documentation.

For some aircraft, such as the Bombardier CL-215, the hose must be attached to the adapter before placing it on the probe. This prevents the probe from twisting or stressing during installation. For other platforms, the sequence may vary, so technicians should follow the instructions provided in the specific Nav-Aids air data kit.

The adapter is compatible with most industry-standard air data test sets when used with the correct Nav-Aids hose assembly supplied in the applicable air data kit. The adapter itself does not regulate pressure but ensures a secure interface for the test set to apply pitot pressures. Always verify compatibility with the kit documentation to ensure correct fittings and hose configurations.

The adapter should be stored in its designated compartment within the air data kit case to prevent contamination or physical damage. Keeping the sealing surfaces clean and free of debris is crucial for maintaining airtight connections. Regular visual inspection helps ensure the adapter remains serviceable for pitot testing.

Maintenance primarily consists of cleaning the sealing surfaces and inspecting the adapter for wear, cracks, or deformation that could compromise leak integrity. No calibration is required, as the adapter does not contain internal measuring components. If damage is found, the adapter should be replaced to ensure accurate pitot test results.

Because each aircraft has unique pitot and static probe designs, Nav-Aids packages the correct adapter combinations into tailored air data kits to ensure a precise fit and safe operation. Including the 18821-4 in these kits ensures technicians have the correct hardware to interface with aircraft-specific probes. This eliminates the risk of using the wrong adapter during critical pitot-static testing.

Yes. When installed on multi-probe aircraft, the adapters enable technicians to isolate left and right pitot systems to identify leaks, blockages, or faulty components. This isolation capability is essential for diagnosing discrepancies in airspeed indications or pitot pressure behavior.

For helicopters such as the AH-64D and CH-136, the adapter provides a secure interface on nose- or fuselage-mounted pitot probes, enabling precise pitot pressure testing even in environments with limited access. Its compatibility with the supplied hose assembly ensures a stable connection, helping technicians perform accurate air data tests on rotorcraft systems.