Trouble in Australia and Israel Compel Emergency AD 2004-06-52

Applicability: Model R22, R22 Alpha, R22 Beta, and R22 Mariner helicopters, with a main rotor blade (blade), part number (P/N) A016-1 or A016-2, installed, certificated in any category.  

Compliance: Required as indicated.

The FAA has sent an Emergency AD notice to all US owners and operators of Robinson Helicopter Company Model R22, R22 Alpha, R22 Beta, and R22 Mariner helicopters.  

According to FAA documents, this "Emergency Airworthiness Directive (AD) is prompted by two accidents that occurred in Australia and Israel that were attributed to failure of the main rotor blade (blade). Investigation revealed that corrosion from water penetration initiated a fatigue crack in a blade. Information from the accident investigations revealed that the cracked blades manifested an increase in helicopter vibration. Following a track-and-balance of the blades, the vibrations would go back to normal for a short time and then slowly increase again until blade failure occurred. This condition, if not prevented, could lead to a fatigue crack, blade failure, and subsequent loss of control of the helicopter.  

This unsafe condition is likely to exist or develop on other helicopters of the same type design." 

Therefore, this AD requires: 

• Within 10 hours time-in-service (TIS) or 30 days, whichever occurs first, track-and-balancing blades that are 5 years old or have 1,000 hours TIS; 
• Replacing the blades with airworthy blades before further flight if an abnormal increase in vibration occurs within 5 hours TIS after the last track-and-balance;
• Within 10 hours TIS or 30 days, whichever occurs first, for helicopters with blades, part number (P/N) A016-1, replacing the blades with airworthy blades other than blades, P/N A016-1, on or before reaching 2,000 hours TIS; 
• Within 10 hours TIS or 30 days, whichever occurs first, for helicopters with blades, P/N A016-2, replacing the blades with airworthy blades other than blades, P/N A016-1, on or before reaching 2,200 hours TIS or 10 years, whichever occurs first; and
• Within 10 hours TIS or 30 days, whichever occurs first, determining the age of each blade and revising the component history card or equivalent maintenance record for blades, P/N A016-2, by adding a 10-year retirement life to the current 2,200 hours TIS retirement life.  

This AD revises the Airworthiness Limitations section of the applicable maintenance manual by adding a new retirement life of 10 years to the current 2,200 hours TIS retirement life. The blades must be retired upon reaching 2,200 hours TIS or 10 years, whichever occurs first.

FMI: Emergency AD 2004-06-52