The report by the National Research Council also expressed concern about the effectiveness of the Federal Aviation Administration’s program to prevent its 15,000 controllers from suffering fatigue on the job, a program that has been hit with budget cuts. And the 12-member committee of academic and industry experts who wrote the report at the behest of Congress said FAA officials refused to allow them to review results of prior research the agency conducted with NASA examining how work schedules affect controller performance.

WASHINGTON — Air traffic controllers are still working schedules known as ‘‘rattlers’’ that make it probable they will get little or no sleep before overnight shifts, more than three years after a series of incidents involving controllers sleeping on the job, according to a government-sponsored report released Friday.


The FAA-NASA research has “remained in a ‘for official use only’ format’’ since 2009 and have not been released to the public, the report said.

The committee stressed its concern that controllers are still working schedules that cram five eight-hour work shifts into four 24-hour periods. The schedules are popular with controllers because at the end of last shift they have 80 hours off before returning to work. But controllers also call the shifts ‘‘rattlers’’ because they ‘‘turn around and bite back.’’

An example of the kind of schedule that alarmed the report’s authors begins with two consecutive day shifts ending at 10 p.m. followed by two consecutive morning shifts beginning at 7 a.m. The controller gets off work at 3 p.m. after the second morning shift and returns to work at about 11 p.m. the same day for an overnight shift — the fifth and last shift of the week.

When factoring in commute times and the difficulty people have sleeping during the day when the human body’s circadian rhythms are ‘‘promoting wakefulness,’’ controllers are ‘‘unlikely to log a substantial amount of sleep, if any, before the final midnight shift,’’ the report said.


‘‘From a fatigue and safety perspective, this scheduling is questionable and the committee was astonished to find that it is still allowed under current regulations,’’ the report said. The combination of ‘‘acute sleep loss’’ while working overnight hours when circadian rhythms are at their lowest ebb and people most crave sleep ‘‘increases the risk for fatigue and for associated errors and accidents,’’ the report said.

Responding to the report, the FAA said in a statement Friday that it is ‘‘adding limitations to its shift and scheduling rules.’’ The statement did not detail the limitations and FAA officials did not immediately respond to a request for clarification

The National Air Traffic Controllers Association defended the scheduling, citing the 2009 study that has not been publicly released. The union said in a statement that NASA’s research showed that ‘‘with proper rest periods,’’ the rattler ‘‘actually produced less periods of fatigue risk to the overall schedule.’’

In 2011, FAA officials and then-Transportation Secretary Ray LaHood promised reforms after a nearly a dozen incidents in which air traffic controllers were discovered sleeping on the job or did not respond to calls from pilots trying to land planes late at night. In one episode, two airliners landed at Washington’s Reagan National Airport without the aid of a controller because the lone controller on the overnight shift had fallen asleep. In another case, a medical flight with a seriously ill patient had to circle an airport in Reno before landing because the controller had fallen asleep.