By AeroCopilot Editorial Team
The FAA has issued Airworthiness Directive FAA-2026-0728, effective May 26, 2026, requiring mandatory replacement of anti-yaw block fasteners on the CRJ-700, CRJ-900, and CRJ-1000 family of regional jets currently held under the MHI RJ Aviation ULC type certificate. The new directive supersedes prior AD 2025-22-02, which had relied on repetitive inspections rather than a hardware change.
For operators of the CRJ series in the United States and abroad, this is a fleet-wide compliance event that will touch maintenance planning, parts logistics, and dispatch reliability through the second half of 2026.
What the directive requires
The anti-yaw block is a structural component that constrains lateral (yaw-axis) movement of the horizontal stabilizer at its attachment to the vertical fin. The FAA's docket cites "repeated reports of loose or missing fasteners which, combined with bird strike or wind gust loads, may cause horizontal stabilizer separation and loss of longitudinal control."
Under the superseded AD, operators were performing recurring visual and torque inspections on the existing fasteners. The 2026 directive concludes that repetitive inspection is insufficient and instead mandates:
- Physical replacement of the anti-yaw block screws with new-specification hardware designated by MHI RJ Aviation ULC.
- Detailed inspection of the anti-yaw block itself, the support bracket, and adjacent primary structure during the same maintenance event.
- Replacement of any discrepant components identified during the inspection, before further flight.
- Logbook documentation of the modification, including hardware part numbers and inspection findings, for future operator and FAA reference.
The directive applies on a per-airframe basis, with compliance times tied to flight cycles and the operator's heavy-check schedule. Operators should consult the AD docket and the MHI RJ Service Bulletin referenced therein for the exact compliance threshold applicable to each tail.
Why the FAA escalated from inspection to replacement
The horizontal stabilizer on the CRJ family provides longitudinal trim and pitch control authority. Loss of stabilizer integrity in flight is a catastrophic failure mode, which is why the FAA's risk model weights any credible separation pathway heavily even when no in-service failure has occurred.
The original 2025 AD was issued after operators reported finding fasteners that had backed off, sheared, or were absent during routine inspections. Subsequent service data indicated that the loosening pattern was recurring across airframes and that inspection intervals were not catching every discrepancy before the next flight cycle. The FAA's determination that "inspection alone is insufficient" is consistent with how the agency has historically handled fastener and structural-attach issues on transport-category aircraft: when the failure mode is catastrophic and the root cause is hardware-driven, the corrective action shifts from detection to elimination.
Operator impact
The CRJ-700/900/1000 remains a workhorse of regional networks in North America, Europe, and Latin America. In the United States, the directive will primarily affect regional carriers operating under capacity-purchase agreements with the major network airlines.
Practical considerations for affected operators include:
- Hangar and slot availability for the modification, particularly for carriers whose heavy-maintenance providers are already running near capacity.
- Hardware lead time from MHI RJ Aviation ULC, including any parts pooling arrangements between operators.
- Dispatch reliability during the compliance window, with possible short-term capacity reductions for smaller fleets.
- Foreign airworthiness validation, including ANAC in Brazil, EASA in Europe, and TCCA in Canada, each of which will typically issue a corresponding mandatory continuing airworthiness instruction within days or weeks of the FAA's effective date.
For pilots, the directive does not change normal procedures, limitations, or the AFM. It is a maintenance action invisible to the flight crew once complete. However, crews should expect to see reference to the AD compliance status on dispatch release paperwork and in the aircraft technical log during the transition period.
Pre-flight relevance
ADs are part of the airworthiness chain that pilots are responsible for confirming before accepting an aircraft. AeroCopilot tracks active and pending FAA ADs against the aircraft you fly and surfaces relevant items in your pre-flight briefing, alongside NOTAMs, weather, and route hazards, so compliance status is visible without manual cross-referencing of the FAA database.
Sources
- Federal Register / FAA Docket: FAA-2026-0728, "Airworthiness Directives; MHI RJ Aviation ULC (Type Certificate Previously Held by Bombardier, Inc.) Airplanes" — https://www.federalregister.gov/
- FAA Airworthiness Directives database — https://drs.faa.gov/
Information current as of publish date; pilots responsible for verifying with current FAA/NTSB sources before flight.