With deference to Charles Dickens, we present in this issue an aerospace version of his A Tale of Two Cities. Actually, we feature two airports, which serve cities with much in common.
Memphis and Milan both are major industrial/commercial centers with several prominent universities and colleges. Both cities are located on an inland, fertile plain. I won’t compare the Elvis Presley museum, Graceland, to Milan’s Sforza Castle or the Memphis Music Hall of Fame to La Scala opera house. Nevertheless, both cities have their share of popular tourist attractions.
Both Memphis and Milan have major air cargo hubs, as well. Indeed, Memphis International Airport is the world’s largest air cargo hub, with air freight traffic accounting for most of the 1,500+ movements tallied there daily. At Malpensa, which also serves major overnight delivery services, such as DHL International and Emery Air Freight, more than 300 million tons of goods and mail were managed last year, 20 percent more than in 1999.
Interestingly, Memphis airport originated primarily as a commercial transport facility and became a cargo hub after overnight delivery services like Federal Express (now FedEx Express) were launched in the early 1970s. Meanwhile, Milan’s Malpensa International Airport has long been an air cargo hub and only recently became a commercial transport facility.
Authorities at both airports have anticipated significant growth in air cargo traffic. On Aug. 26, FedEx launched a fast-delivery service for the U.S. Postal Service, virtually doubling the number of its afternoon flights. Meanwhile, a new cargo facility to host more than 200 air freight operators is planned for Milan Malpensa. Called Cargo City, it will occupy 10.7 million square feet (1 million square meters) and cost $141.3 million (300 billion lire).
Small wonder, with all of this air operations activity, that safe and efficient ground traffic management was stressed in the modernization plans for both airports. As written in our report on Malpensa (page 22) and Memphis International (page 28), both facilities are equipped with sophisticated systems to manage surface movements. The two airports have different tales to tell in surface management, but they share the goal of increasing traffic throughput while reducing, if not eliminating, runway incursions. The U.S. Federal Aviation Administration (FAA) defines a runway incursion as a situation involving "an aircraft, vehicle, person or object on the ground that creates a collision hazard or results in a loss of separation with an aircraft taking off, intending to take off, landing or intending to land."
The runway incursion problem is both serious and complex. Serious because, according to FAA statistics, the number of reported runway incursions in the United States jumped from 186 in 1993 to 431 in 2000, a 132 percent increase.
On Aug. 17, a Delta Air Lines B737 was cleared for takeoff at Dallas-Fort Worth Airport. Meanwhile a Continental B737, which had just landed, was directed to cross the same runway. The Delta aircraft pulled up sharply, missing the Continental aircraft by just 500 feet (152 meters), scraping its tail on the runway surface. The FAA blamed the incursion on controller error.
On Aug. 13, another runway incursion occurred. Again, controller error was suspected, though the incident remained under investigation as this was written. What is disturbing about this incursion is that it occurred where it shouldn’t have: Milan Malpensa Airport.
The latter incident shows how complex resolving the incursion problem can be. Technology, alone, won’t resolve it. A statistical history of incursions further confounds the pursuit of definitive answers. According to FAA figures, contrary to conventional wisdom, weather was not a factor in 89 percent of the runway incursions. Though controller error obviously is a factor, as was evident at Dallas-Fort Worth and Milan Malpensa, 60 percent of the runway incursions over recent years have been caused by "pilot deviations"–taxiing onto runways or taxiways without clearances, distractions, unfamiliarity with ATC procedures or language, etc. Although general aviation pilots accounted for a majority (69 percent) of the runway incursions, a significant number (10 percent) were caused by high-time pilots, according to the FAA.
The elimination of runway incursions obviously requires a multifaceted approach. Improved human factors–clear, concise communications between tower and pilots, proper cockpit procedures, and pilot familiarity with the airport and surface markings–clearly are essential. Technologically, controller awareness through fused data from various inputs is critical, but so, too, is pilot awareness–which is why the Head-up Surface Guidance System shows merit.
The crusade to curb runway incursions continues at Milan Malpensa, where authorities are examining controller procedures and controller use of the airport’s state-of-the-art systems, and the effort progesses at Memphis International, which an FAA official described as "a prototyping and R&D environment" for new developments in surface movement management. These two airports are on the front line in the battle against runway incursions–which is why we tell their tales in this issue.