Air Safety Link
Court Upholds ‘Whitlow Letter’ 16-Hour Duty Limit

Air Line Pilot, July/August 2002, p.5
By Air Line Pilot staff

A U.S. Court of Appeals panel lifted a stay, obtained by the Air Transport Association and the Regional Airline Association, against the FAA's enforcement of pilots' 16-hour maximum duty day.

ALPA won a substantial victory at the end of May in the continuing battle to secure adequate rest under real-world conditions.

The U.S. Court of Appeals for the District of Columbia Circuit, in a unanimous, three-judge panel decision, upheld an FAA interpretation of FAR 121.471b, clarifying that 16 hours is the maximum time a pilot may remain on duty, regardless of delays caused by weather, air traffic control, or maintenance.

Current regulations limit scheduled flight time for domestic operations to a maximum of 8 hours in a single duty period, with that limit to be exceeded only under circumstances beyond a carrier’s control. Another section of the rule requires that pilots "look back" after every arrival and find at least an 8-hour scheduled rest period during the previous 24 hours.

FAA Deputy Chief Counsel James Whitlow in November 2000 issued an interpretation of the rule in terms of delays, stating, "If, when using the actual expected flight time [for a flight segment], the carrier cannot find at least eight hours of look-back rest upon arrival, then the flight may not depart [on that segment]."

Specifically, the Whitlow letter said, "If, when this information is factored in, it is known or should be known that arrival based upon the actual expected flight time will not result in at least eight hours of look-back rest, then the flight may not leave the gate. If the flight is away from the gate, but not yet in the air, then the flight may not take off."

The ruling therefore requires pilots and airlines to continuously monitor delays, particularly during long duty periods, to ensure that a flight will not violate the rest requirements under the FARs. Both pilots and air carriers have a regulatory duty to not violate the rule.

The FAA announced in May 2001 that it would enforce the interpretation and later review airline flight scheduling practices.

The Air Transport Association, representing the majority of U.S. airlines, filed suit on Jan. 18, 2001, against the FAA, challenging the interpretation and contending that as long as airlines did not actually schedule a pilot to be on duty longer than 16 hours, the pilot would be legal to continue flying until the end of the flight schedule. The ATA suit, supported by the Regional Airline Association, contended that the FAA interpretation represented a departure from past practices and prior interpretations and thus constituted rulemaking, requiring public notice and comment.

ALPA, who was an intervenor in support of the FAA, argued in January that blocking the interpretation would essentially permit airlines to keep pilots on duty for unlimited periods of time, particularly if the pilots had no contractual protections limiting their time on duty.

The May 31 ruling by the District of Columbia Circuit Court panel said that the FAA "reasonably interpreted the required rest regulation to re-quire a carrier to recalculate past rest periods in light of actual flight times, including those scheduled flight times required to be rescheduled by existing flight conditions."

The ATA and the RAA have until July 15 to seek reconsideration of the panel decision by the full U.S. Court of Appeals, or review by the U.S. Supreme Court. Meanwhile, the FAA plans to move ahead on training its inspectors and en-forcing the rule. ALPA will keep its members advised of additional developments.

ALPA issued a statement on May 31 after the ruling was announced, calling on the FAA to immediately resume enforcing the rule "in accordance with its own interpretation." The Association added, "We also call on airlines to immediately begin scheduling pilots under the FAA interpretation, rather than their own."

ALPA also called for long-delayed revisions to the flight and duty time regulations. "For more than six years, revisions to the basic flight and duty time limits for pilots have been bottled up at the FAA because of airline opposition," the Association charged. "With the airlines’ suit now cleared from the deck, it’s time for the FAA to move forward with an update of these regulations."

The complete text of the ruling on the "Whitlow letter" can be found on the "Preventing Pilot Fatigue" portion of ALPA’s website ( under "FAA Interpretations."