Airworthiness Directives; Hélicoptères Guimbal Helicopters

Document 2026-11506 is a Final Rule published by the Department of Transportation in the Federal Register on June 9, 2026, with an effective date of June 24, 2026. The FAA is adopting a new airworthiness directive (AD) for all H[eacute]licopt[egrave]res Guimbal (HG) Model Cabri G2 helicopters. The FAA previously sent this AD as an emergency AD to all known U.S. owners and operators of these helicopters. This AD was prompted by a report that was received of a crack on the main rotor (MR) mast after the crew reported an abnormal increase of vibration. This AD requires inspecting the MR mast for cracks and corrosion pitting, and depending on the results of the inspection, accomplishing corrective actions. This AD also requires modifying the MR mast, which includes applying corrosion protection to the MR mast, reporting the inspection results and prohibiting the installation of a certain main gear box (MGB), unless certain requirements are met. The FAA is issuing this AD to address the unsafe condition on these products. View the original at https://www.federalregister.gov/documents/2026/06/09/2026-11506/airworthiness-directives-hlicoptres-guimbal-helicopters.

No. Document 2026-11506 is not classified as economically significant under Executive Order 12866. Economically significant rules require OIRA review and are estimated to have impacts of $100 million or more per year.