West Star Aviation is advising Bombardier Challenger operators of a newly issued FAA Airworthiness Directive (AD) that addresses a critical — but easily correctable — component within the nosewheel steering (NWS) system.

AD 2026-06506 applies to:

• CL-600-1A11 (Challenger 600)
• CL-600-2A12 (Challenger 601)
• CL-600-2B16 (Challenger 601-3A, 601-3R, and 604 variants)

This directive highlights how a small component can present a serious operational risk if left unaddressed.

The Issue: Uncommanded Nosewheel Steering

The AD was prompted by a confirmed event involving uncommanded nosewheel steering during landing, despite the aircraft touching down on the runway centerline.

The FAA has determined the root cause to be:

• Loose, worn, or degraded setscrews
• Located in the nosewheel steering rudder pedal potentiometer universal coupling

If these setscrews loosen or fail, the integrity of the steering input can be compromised — leading to unexpected nosewheel movement during critical phases of operation.

AD Requirements

To address this condition, the FAA mandates the following actions:

Immediate Compliance (See Paragraph G in the linked AD)

Operators must replace the affected setscrews in accordance with:

• Bombardier SB 601-1114
• Bombardier SB 604-32-033

Ongoing Maintenance Requirement

Operators are also required to revise their maintenance or inspection programs to include:

• A mandatory 96-month (8-year) replacement interval for the setscrews

This establishes a recurring requirement to ensure long-term system reliability.

Service Bulletin vs. Inspection Requirement: Key Clarification

The applicable Bombardier Service Bulletins reference replacement of both the coupling and the setscrews.

However, it is important to note:

• The 96-month recurring requirement applies specifically to the setscrews only.
• Full coupling replacement is not required at each interval, unless otherwise indicated by condition or inspection findings.

Understanding this distinction can help operators better plan maintenance scope, cost, and downtime.

Minimal Downtime, Maximum Impact

The good news for operators: this is a straightforward correction with minimal operational disruption.

• Typical downtime approximately one day
• Can be easily incorporated into scheduled maintenance events

West Star Aviation has already successfully completed multiple installations related to this requirement, demonstrating both efficiency and familiarity with the procedure.

West Star Aviation: Your Challenger Technical Resource

West Star Aviation brings decades of experience supporting the Bombardier Challenger platform, including avionics, structures, inspections, and flight control systems.

As a trusted MRO partner, West Star provides:

• Expert interpretation of FAA ADs and OEM service bulletins
• Efficient compliance planning to minimize downtime
• Proven installation experience with repeatable, high-quality results
• Integrated scheduling to combine AD compliance with other maintenance events

Our teams understand not just the “what” of compliance — but the “how” to execute it efficiently.

Plan Ahead for Compliance

While the corrective action is technically simple, proactive planning ensures:

• Timely compliance (Refer to Paragraph G of the attached AD)
• Minimal disruption to operations
• Efficient coordination with other scheduled maintenance