AD 2013-19-06 78 FR 60185

We are adopting a new airworthiness directive (AD) for Robinson Model R22, R22 Alpha, R22 Beta, and R22 Mariner helicopters with certain fuel shut-off valves installed. This AD requires replacing the fuel shut-off valve with a newer design fuel shut-off valve. This AD is prompted by three accidents that occurred because the fuel shut- off valve was inadvertently moved to the "off" position. These actions are intended to prevent inadvertent closing of the fuel valve, which could result in engine power loss from which a safe landing may not be possible.