From The Ergoweb® Learning Center

Can the New FAA Standard Reverse Rising Figures for Runway Incursions?

The Federal Aviation Administration (FAA) standard for runway markings becomes mandatory for 75 of the nation’s major airports on 30 June 2008. It was designed to help prevent runway incursions by enhancing markings so they are easier to see and interpret. The standard is intended to complement a suite of mainly voluntary standards and initiatives. Packaged as the agency’s “corporate approach,” these haven’t reversed the upward trend in incursions. The impact of the standard could be slight – poor markings are only one part of the complex choreography of runway risk factors – but even a small success could challenge the present supremacy of the voluntary approach to aviation safety.

In an interview with the New York Times in April, the chairman of the National Transportation Safety Board, Mark Rosenker, described the time in the plane before takeoff or after landing as “the most dangerous aspect of flying."

The standard applies in 2008 to airports that have more than 1.5 million passenger enplanements in a calendar year. Airports with fewer than 1.5 million enplanements but more than 370,000 have until 30 June 2009 to comply. Several other airport categories have two years to meet the standard.

Aiming for Simplicity

The standard is not reader-friendly – there are rules, sub-rules, tables and figures covering individual circumstances beyond counting – but it is a simple system and it isn’t new. The common requirement is for enhancements to the present system for marking runways and taxiway holding positions. Building the new on the old is presented as a way to keep confusion and additional training to a minimum.

The standard determines where lines should be continuous and where they should be dashed, and how to handle intersecting lines. Visibility enhancements, such as glass beads in the yellow taxiway centerline, are also specified. And on light pavement, the yellow must be outlined in black. It also specifies runway holding position markings, which identify the location on a taxiway where a pilot has to stop while waiting for clearance to proceed onto the runway.

The enhancements are designed to assist drivers on runways as well as pilots. Some 20 percent of runway incursions between 1999 and 2002 involved tugs, maintenance carts and baggage and fuel trucks.

Ergonomist Fingerprints

The specification that the markings need to emphasize a preferred route through a confusing intersection shows ergonomist fingerprints on the standard.  It draws on findings from the Enhanced Surface Markings Project, published in the Spring 2005 issue of Ergonomics in Design. The scientific quarterly described the project as a successful collaboration among human factors/ergonomics (HF/E) consultants, the FAA and aviation industry representatives.

The HF/E researchers recommended a modified centerline extending 150 feet from the runway holding position, with a pattern of dashes on either side to warn pilots that a runway is approaching; surface-painted holding position signs at all runway intersections and on both sides of the centerline; and a modified runway hold line with white dashes, instead of yellow, to indicate the runway side and not the taxiway side. The first two recommendations were incorporated into the standard.

A Telling Record of Accidents and Near-misses

The crash in August 27 of a Comair CRJ-100 in Kentucky that killed 49 of the 50 people on board was the most recent fatal runway accident. It thrust runway incursions and flawed airports and airport operations into the headlines. The pilots of the Comair jet had taken off from the wrong runway, a short spur reserved for small private planes. According to the USA Today article about the accident, pilots report that it is easy to mistake one runway for another, particularly at night or in poor weather.

Near misses are frequent. The most recent, reported by the Associated Press, involved a Southwest Airline jetliner at Los Angeles International Airport on June 10. It reached  within 50 yards of a runway where another plane was preparing to land. FAA spokesman Ian Gregor said the pilot of a Southwest flight bound for Sacramento on Sunday morning did not have permission from a controller to cross over onto the runway.

A near miss on April 6 at Dallas-Fort Worth International Airport was one of very few that wasn’t attributed to human error. A tug operator pulling a Boeing 777 along a taxiway failed to stop at a runway as another plane was landing, missing the tug by about 25 feet. The incident was described as one of the closest near misses on record. The mechanics towing the plane were unable to stop near the runway and pulled the plane into the path of an incoming flight. After the incident, mechanics complained the tug’s brakes didn’t work well enough to stop the heavy plane.

The tug was blamed. American Airlines bought the Goldhofers-brand tugs, which can pull planes across runways at high speed without the assistance of the plane’s engines, because they save fuel.

The FAA has reported small increases in runway incursions—defined as the "incorrect presence" of a plane or other moving object on a runway being used for takeoffs and landings—every year since it introduced its so-called “corporate approach” to reducing the numbers. Fiscal year 2003 saw 323 incursions. FY 2007 saw 370.  The number of these deemed serious (meaning there was a strong likelihood of a crash) more than doubled, to 15, in recent months from the same period a year earlier.

The FAA dismisses the rise as the result of changes in the way incidents are reported.  The agency formerly tracked and monitored low-risk incidents – those with no conflict potential or ample time or distance to avoid a collision – as surface incidents and not as runway incursions. Most of these are now tracked as Category C or D runway incursions.
The number of serious runway incursions – categories A and B – dropped by more than 55 percent from fiscal year 2001 through FY 2007, the agency says, describing the total of 24 serious incursions for FY 2007 as an all-time low. Presenting other figures as evidence its approach is working, the agency says 92 percent of the 370 incidents in 2007 presented ample time and/or distance to avoid a conflict or presented no immediate danger.

The agency points out that the 24 incidents have to be viewed in the context of 30 million commercial flights in the United States last year.

The “Corporate Approach”

The meeting in of Acting FAA Administrator Bobby Sturgell with aviation leaders from airlines, airports, air traffic control and pilot unions and aerospace manufacturers in 20007 exemplicies the "corporate approach." They agreed on 15 August 2007 to an initiative to improve safety at US airports by focusing on solutions in cockpit procedures, airport signage and markings, air traffic procedures and technology. Other short-term steps focused on improved procedures and increased training for airport and airline personnel.

There was no talk of enforcement measures, and no talk of root causes. 

Writing in USA Today in December, Najmedin Meshkati, a professor of engineering and an aviation safety researcher and instructor  at the Viterbi School of Engineering, University of Southern California – Los Angeles, took issue with the FAA’s assertion that its aggressive efforts to make airports safer are delivering significant results. “Some of the most notable causes of incursions are poor visibility, fatigue, air traffic controller’s workload, deficient radar systems, pressure on cockpit crews and inconsistent communication practices,” he observed. There also are strong indications that air traffic controllers are increasingly suffering from cumulative fatigue, the term given to the condition workers face after working long hours for consecutive days, he added.

Overcrowded airports mean overcrowded runways, taxiways and ramps exacerbate all other risks. They take place in a complex and dynamic environment where root causes are difficult to isolate.

The FAA’s Runway Safety Council could win points from Professor Meshkati and the human factors and ergonomics community, which has always urged accident investigators to look behind human errors for root causes. Comprised of 12 to 15 representatives from various parts of the aviation industry, according to the FAA description, a working group will integrate investigations of severe runway incursions, conduct a root cause analysis, present the analysis it to the council, and make recommendations. The council will review the recommendations. If accepted, they’ll be assigned to the part of the FAA and/or the industry that is best able to control the root cause. The council will track recommendations to make sure appropriate action is taken.

Several of the FAA’s initiatives show awareness of ergonomics principles, and are also ripe for standards with “teeth” – if the anti-regulation climate in Washington changes with the incoming administration in 2009.

The agency identified a need for more explicit instructions for taxiing, runway crossings, take off and multiple landings, International surface phraseology such as "line-up and wait" could replace the US phraseology, "position and hold."

A standard for end-round taxiways, which removes the need for aircraft to cross runways used for takeoffs and landings at the busiest airports, has been introduced. New end-round taxiways at Atlanta and Dallas-Fort Worth will eliminate more than 2,000 runway crossings each day, according to the agency.

It is encouraging operators to build perimeter roads around the airfield so that vehicles do not have to be driven across taxiways and runways. Certain runway/taxiway intersections will be enhanced with a stop bar, which is a series of in-pavement and elevated red lights that indicate to pilots that they may not cross.

In partnership with industry and airport operators, the FAA is developing a soft-ground arrestor system to quickly stop aircraft that overrun the end of a runway where there is not enough level, cleared land for a standard runway safety area. The system has been installed at 21 airports, and there are plans for more.

Communications methods are being overhauled. The FAA wants airports to provide airlines and pilots with diagrams giving the latest information on runway construction and closings. This would be distributed by email, on a web site or hand-delivery. The measure would supplement Notices to Airmen (NOTAMS), which are printed as text or delivered verbally, and thus do not have diagrams.

Training is emphasized. The FAA recommends regular recurrent driver training for people with access to movement and ramp apron areas. At commercial airports, it requires the training.

Its technology strategy includes wider use of the Airport Movement Area Safety System (AMASS), a radar-based system that tracks ground movements and provides an alert to controllers if evasive action is required. Airport Surface Detection Equipment, Model X (ASDE-X) is a more sophisticated surface detection technology than AMASS, which is radar-based and vulnerable in poor weather. ASDE-X integrates data from a variety of sources, including radars and aircraft transponders, to give controllers a more reliable view of airport operations.

The agency is testing Runway Status Lights. Just as it sounds, the system is a series of runway lights, like traffic lights, that tell pilots whether or not runways are clear. Surface and terminal surveillance systems, such as ASDE-X and AMASS, detect the presence and motion of aircraft and vehicles on or near the runways. The Runway Status Light safety logic then assesses any possible conflicts with other surface traffic.

Another technology under review is the Final Approach Runway Occupancy Signal (FAROS). It is designed to prevent runway accidents by activating a flashing light visible to landing pilots to warn them that the runway is occupied and hazardous.

The FAA and the aviation industry are also developing moving map displays in the cockpit that show an aircraft’s precise position on the airfield. By using this Own-ship Position system, pilots will be able to pinpoint their location on the airfield and avoid being in the wrong place.

In his December article, Professor Meshkati argued that throwing more technology into the runway problem does not address human factors and human error, and his point is made by the continuing upward trend in incursions. The FAA’s “corporate approach,” which reflects the emphasis on self-regulation by the industry, hasn’t reversed the trend.  It remains for the new FAA standard to make its mark on the figures. But the FAA can fend of attacks on its approach by reminding legislators and critics that United States commercial aviation is enjoying its safest period in history. The last major fatal US air crash occurred in August 2006.

Sources: New York Times; USA Today; FAA


This article originally appeared in The Ergonomics Report™ on 2008-06-11.