In response to a recent accident involving a rotor blade separation in a Robinson R-22 aircraft, Robinson Helicopter Company has issued a Safety Alert dated December 1, 2004:
Robinson Helicopter Company
(edited to include RHC link - B.B.)
Thanks for posting this.
Despite the link in the last para, the notice hasn't been put on the RHC site yet. I've posted it below for information.
Heliport
In response to a recent accident involving a rotor blade separation in a Robinson R-22 aircraft, Robinson Helicopter Company has issued a Safety Alert dated December 1, 2004:
R-22 Safety Alert: Exceeding Manifold Pressure Limits Can Cause Blade Failure. An A016-2 main rotor blade failure recently occurred at only 700 hours time in service. Although R-22 blades have a 2,200 hour service life, repeated over-stressing can substantially reduce blade fatigue life. Exceeding manifold pressure limits produces excessive stress and can result in premature fatigue failure.
Warning:
1) If the helicopter has been occassionally operated above manifold pressure limits, replace main rotor blades.
2) If the helicopter is normally parked outside in humid climates, particularly in tropical or coastal areas, replace A016-2 main rotor blades prior to 5 years time in service due to possible internal corrosion.
3) If main rotor vibration increases during flight, make an immediate safe landing and determine the cause of vibration before further flight. If cause cannot be determined, replace main rotor blades before further flight.
Operators are also reminded to reread Safety Notices SN-37 and SN-39. Safety Notice 37, "Exceeding Approved Limitations Can Be Fatal" was issued on December 1, 2001. Safety Notice 39, "Unusual Vibration Can Indicate A Main Rotor Blade Crack" was issued in July 2003. These Safety Notices can be viewed at Robinson Company web site.