Regulators in Canada, Europe and the United States have adopted an emergency airworthiness directive (EAD) for Bell 505 helicopters due to reports of cracked vertical stabilizer caps.
There have been “multiple occurrences” of cracked vertical stabilizer top end cap assemblies, said Transport Canada in an EAD issued Jan. 25, 2024.
According to Transport Canada, in some cases, NAV/VOR/GS antennas and tuning weights have departed from the helicopter during flight.
“Detailed investigation has identified that the stabilizer top end cap assembly was not designed for the full fatigue spectrum,” Transport Canada said.
“The investigation has determined that if no corrective actions are implemented, there is potential for the antenna and tuning weight to depart, which could impact and damage the tail rotor resulting in the loss of directional control of the helicopter.”
The Transport Canada EAD applies to Bell 505 helicopters including and subsequent to serial number 65011. It mandates an initial inspection, instructions for replacing the vertical stabilizer top end cap, if required, and a recurring inspection of the top end cap for cracks.
All affected aircraft are required to have a detailed visual inspection within 10 flight hours of Jan. 29, followed by additional inspections every 25 flight hours.
A detailed list of corrective actions is available at the Transport Canada website.