Airworthiness Directives; Robinson Helicopter Company Model R44 Helicopters

This amendment supersedes an existing airworthiness directive (AD), applicable to Robinson Helicopter Company Model R44 helicopters, that currently requires revisions to the Limitations section, the Normal Procedures section, and the Emergency Procedures section of the R44 Rotorcraft Flight Manual, revised September 6, 1994. These revisions limit operations in high winds and turbulence; provide information about main rotor (M/R) stalls and mast bumping; and provide recommendations for avoiding these situations. Additionally, emergency procedures are provided for use should certain conditions be encountered. This amendment requires the same revisions required by the existing Priority Letter AD, but revises certain words and phrases to further clarify the revised Limitations and Normal Procedures sections, deletes the paragraph that referenced recording compliance with the AD, and adds another paragraph that states that no special flight permits will be issued prior to compliance with this AD. This amendment is prompted by two Model R44 accidents since April 1994 involving M/R blades contacting the helicopters' fuselage; and, 26 accidents involving M/R blades contacting the fuselage on the Model R22 helicopter since 1981. The Model R22 helicopter M/R system design is similar to the Model R44 helicopter M/R system design. The actions specified by this AD are intended to prevent M/R stall or mast bumping, which could result in the M/R blades contacting the fuselage causing failure of the M/R system and subsequent loss of control of the helicopter.