Robinson Helicopter Company has issued two service bulletins, impacting some tail rotor blades installed on R44 and R66 helicopters, after reports of corrosion cracks on R44 tail rotor blades.
According to the R44 service bulletin, the affected C029-3 tail rotor blades have developed a spanwise corrosion crack along the leading edge of the blade.
“Early reports involved blades manufactured from a single lot of skin material with a suspected heat treat anomaly,” the bulletin states. “An additional lot of blade skins has been identified.”
Impacted blades have serial numbers (S/Ns) from 9910 through 10659, and were factory-installed on R44 S/Ns 2599 through 2619; R44 II S/Ns 14360 through 14394 (except 14363); and R44 Cadet S/Ns 30064 through 30068.
Affected blades were also shipped as spares between August 2019 and December 2020.
The R66 bulletin states the impacted F029-1 tail rotor blades have S/Ns 2410 through 2589, and were installed on R66 S/Ns 1035 through 1090 (except 1039, 1067, 1076, 1077, and 1081). Some affected blades were shipped as spares between January 2021 and November 2021.
The blades must be removed from service, and operators must perform an additional preflight inspection to continue to operate them until they are replaced.
If a helicopter is equipped with an affected tail rotor blade, a special preflight inspection page must be added to the operating handbook within the next 10 flight hours or by Jan. 31, 2022. They must be replaced by Dec. 31, 2022.
