By Kim Smiley

At least three times over the past decade, air traffic controller fatigue has been investigated by the National Transportation Safety Board (NTSB) in near-miss airline accidents.  Five years ago, controller fatigue was a significant factor in a Lexington, KY crash killing 49, the last fatal crash related to this problem.  Again last week, controller fatigue was in the news when two early-morning aircraft had uncontrolled landings at Reagan National Airport near Washington D.C.  The controller, who had 20 years of experience with most of them at Reagan, was clearly well experienced.  In fact, the controller was also a supervisor.  But no level of experience can overcome the effects of fatigue.  The relieved controller stated that he had worked the 10 p.m. to 6 a.m. shift four nights in a row.

Faced with harsh criticism over the latest incident, the FAA reacted by mandating a second controller at Reagan National Airport and reviewing traffic management policies at all single-person towers.  Regional radar controllers are now required to check in with single-person towers during night shifts to ensure controllers are prepared to handle incoming traffic.

Controller fatigue is a well known problem, and multiple solutions have been suggested over the past two decades.  It has been a part of the NTSB’s Most Wanted list since 1990.  In 2007 following the Lexington crash, the NTSB urged the Federal Aviation Administration (FAA) to overhaul their controller schedules, claiming that the stressful work and hectic pace were putting passengers and crews at risk.  The FAA responded, and is currently working with the National Air Traffic Controllers Association (NATCA) to develop “a science-based controller fatigue mitigation plan”.

In addition, from 2007 to 2011, more than 5,500 new air traffic controllers were hired.  However, many of these simply replaced air traffic controllers who were retiring, resulting in no net gain in the pool of available labor.  Air traffic controllers have a mandated retirement age of 56, with exceptions available up to age 61.  Additionally, on-the-job training is extensive, requiring two to four years just to receive initial certification.  Adding staffing therefore is more difficult than initially meets the eye.

Faced with an expected increase in air traffic and an aging infrastructure, the FAA has aggressively pursued a long-term modernization called NextGen.  With the proposed modernization and staffing, the 2011 FAA budget request is now $1.14B, a $275M or 31% increase from 2010.  While material and personnel changes are often necessary, sometimes simpler solutions are equally effective or quicker to implement.

The associated Cause Map reflects the multiple solutions suggested, and even implemented, to combat the problem of controller fatigue.  As discussed, the FAA, NTSB and NATCA have pursued multiple paths to overcome the issue of controller fatigue.  However, as the Cause Map shows, there are multiple contributing factors in this case.  Controller fatigue isn’t the only reason those planes had an uncontrolled landing, and controller fatigue wasn’t caused by just four night shifts in a row.  Because there are multiple reasons why this happened, it also means there are multiple opportunities to correct future problems.  The key isn’t eliminating all of the causes, but rather eliminating the right one.