The Federal Aviation Administration has issued a new airworthiness directive targeting a family of Bombardier Challenger business jets after a confirmed incident of uncommanded nosewheel steering during landing — a failure that occurred even as the aircraft touched down squarely on the runway centerline.
AD 2026-06506, published April 3, 2026 in the Federal Register and effective May 8, 2026, covers all Bombardier Model CL-600-1A11 (Challenger 600), CL-600-2A12 (Challenger 601), and CL-600-2B16 (Challenger 601-3A, 601-3R, and 604 Variants) on the U.S. register.
A Small Component, a Serious Risk
The FAA traced the unsafe condition to loose or degraded setscrews in the nosewheel steering rudder pedal potentiometer universal coupling. When those setscrews degrade, the system can receive erroneous steering inputs — causing the nose gear to deflect independent of pilot rudder pedal commands during rollout.
Uncommanded directional deviation during landing rollout carries significant runway excursion risk. Even modest lateral forces at approach or rollout speeds can push an aircraft toward runway edges or past overrun zones. FODNews has tracked a pattern of such events, including the Learjet overrun at Teterboro that activated EMAS arrestor beds and a Piper Saratoga runway excursion and fire at Marana Regional Airport.
What the AD Requires
The directive mandates two separate corrective actions:
Immediate setscrew replacement. Operators must replace the nosewheel steering rudder pedal potentiometer universal coupling setscrews per Bombardier service bulletins — SB 601-1114 for Challenger 600 and 601 models, and SB 604-32-033 for the Challenger 604.
Revised maintenance life limits. Operators must also update their maintenance or inspection programs to impose a mandatory 96-month replacement cycle for the setscrews going forward.
The AD was triggered by Mandatory Continuing Airworthiness Information (MCAI) issued by Transport Canada Civil Aviation (TCCA), reflecting the bilateral safety coordination framework used for Canadian-manufactured aircraft operating in the U.S.
Fleet Scope and Compliance Resources
The Challenger 600-series has served corporate and government operators worldwide for decades. The AD covers all three model designations on the U.S. register — a significant portion of the active business jet fleet.
Operators can contact the Bombardier Business Aircraft Customer Response Center at 514-855-2999 or through my.bombardier.com. The full AD docket, including public comments from the rulemaking process, is available under Docket No. FAA-2025-1732 at regulations.gov.
The FAA has intensified its runway safety focus in 2026. The agency’s updated runway incursion hot spots guidance underscores a broader push to reduce ground-level risk across the national airspace system.
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