The FAA has issued a final rule for an Airworthiness Directive for the Embraer Phenom 100 S/N 50000005 through 50000118, 50000120, 50000122 through 50000126, 50000128, and 50000131, certified in any category. The AD says it is prompted by failures of the flow control shutoff valve in the closed position. Failure of the two valves (left and right) can lead to loss of cabin pressurization. According to the AD, at the next scheduled maintenance check–or within 12 months after the effective date of the AD or 600 hours time-in-service, whichever occurs first–both flow control shutoff valves must be replaced. The FAA estimates the AD will affect 79 aircraft of U.S. registry and require approximately four work-hours per aircraft to comply, at a cost of approximately $10,487 per aircraft. According to a spokesman for Embraer, the parts cost of the AD might be covered under warranty. The AD takes effect December 14