Summary
The FAA proposes to supersede an existing airworthiness directive (AD) for certain Model A310; and Model A300 B4-600, A300 B4- 600R, and A300 F4-600R (collectively called A300-600) series airplanes. That AD currently requires modifying the ram air turbine (RAT) by replacing the ejection jack. This proposed AD would require a one-time inspection of the RAT ejection jack to determine the part number, and further investigative and corrective actions if necessary. This proposed AD is prompted by the discovery of a rupture in the housing of one of the RAT ejection jacks installed as specified in the existing AD. We are proposing this AD to prevent rupture of the housing of the RAT ejection jack due to overpressure in the jack caused by overfilling the hydraulic fluid, and consequent failure of the RAT ejection jack. Failure of the ejection jack could result in a lack of hydraulic pressure or electrical power in an emergency.