Heralded as "the airport for the 21st century", sceptics began to believe that Denver International (DIA) might not see its first passenger until then.

Technical problems involving the airports automated baggage-handling system, delayed DIA's grand opening four times, for a total of 16 months. Each month cost the taxpayer about $33 million in debt service and other delay costs and, in the end, the City of Denver was forced to install a $53 million conventional conveyor/tug-and-cart baggage system. Today, the luggage at DIA is kept on the move with a combination of manual and automated baggage-handling systems.

By most accounts, Denver's "push night" - in which the 66-year-old nearby Stapleton International Airport was shut down and DIA started operations- took place without any major hitches.

The transition, which began on 27 February, involved shifting air operations between the two airports, moving airport equipment, and transferring about 23,000 rental cars to the new site.

Flight operations were phased down at Stapleton after midnight, and one runway was converted into a loading area for removal vans. Airport rescue and fire-fighting equipment began moving to DIA later the next afternoon. DIA's 327ft (100m) control tower, the tallest in the world, was then activated to handle the arrival of ferry flights from Stapleton.

That night, large yellow Xs were painted on Stapleton's six runways to indicate closure, and DIA's $8.5 million tower and terminal radar approach control (Tracon) became operational at one minute past midnight on 28 February.

DIA - the USA's first entirely new airport in 20 years - opened for business with a 06.00 United Airlines departure.

United has the most to lose, or the most to gain, as the largest tenant at DIA. It uses 45 gates on the B Concourse in support of 290 daily departures to 62 destinations nationwide. At Stapleton, United flights were spread over three different concourses.

For the convenience of the new operation, United passengers using DIA must pay more. The carrier has raised ticket prices on all flights starting or ending at DIA, to offset higher airport-user fees. Round trips starting there have been increased by $40.


Apart from United, airline support for DIA remains lukewarm. Delta has agreed only to a short-term lease, but UPS Airlines, Airborne Express and FedEx plan substantial operations. AMR Combs is operating the general-aviation fixed-base operation there.

Continental Airlines, which had its third-largest hub at Stapleton International, was losing $12 million a month and it elected to cut severely its planned services to DIA. The City of Denver sued Continental, to force the carrier to abide by its original agreement to lease 20 gates at the new airport. An out-of-court settlement allowed the cash-strapped US carrier to be responsible for only ten gates. After five years, Continental may cut back to three gates without penalty.

With its Teflon-coated glass fibre-reinforced-plastic roof and its underground "people-mover" rail system, DIA can be described as "high-tech". It is ironical, then, that the largest single cause of delay has been the Integrated Automated Baggage Handling System (IABHS) built by BAE Automated Systems of Dallas, Texas, under a $230 million contract.

Before the airport's opening, the IABHS was debugged and the system was stressed to test the solutions. Despite assurances from BAE, United is using the automated system only to move bags from the terminal to its aircraft. It is, however, using it to transport outsized items, such as skis, in both directions. It is unclear when United will place its confidence in IABHS, or when other carriers will join United in using the system.

BAE's system is computer-controlled, with the key component being a destination-coded vehicle (DCV) resembling a small mining car, which runs on a track. More than 2,000 linear induction motors propel the DCVs along 35km (21 miles) of track. The DCVs accept luggage automatically and transport and discharge baggage. Laser scanners keep track of luggage and the DCVs as they roll rapidly beneath the airport. More than 3,500 DCVs are available during peak travel seasons.

DIA's land-side terminal building is connected to three airside concourses (A, B and C) by an underground Automated Guideway Transit System "people-mover" made by AEG Transportation Systems (formerly AEG Westinghouse Transportation Systems).

Airport and US Federal Aviation Administration officials concede that they underestimated the number of cars needed. Four additional cars have been ordered, but they will not be delivered for at least a year. Passengers may also walk between the terminal building and Concourse A.

Trains depart every 2min and are designed to transport 6,000 passengers an hour in each direction. A trip to Concourse C takes an average of 4min. DIA has 88 gates. Plans call for expansion to 260 gates by adding two more concourses and lengthening the existing three.

Denver International opened with five 3,700m runways. Plans for construction of a sixth, 4,800m, runway this year are in limbo. The new runway would accommodate long-range, wide-body aircraft used for international flights.


Each existing runway has a full-length parallel taxiway with associated entrance and rapid-exit taxiways. The airport is designed for up to 12 runways (eight running north to south and four east to west) to be constructed as required. Stapleton did not allow for simultaneous landings during instrument-flight-rule conditions. During foul weather, Stapleton handled no more than 30 arrivals an hour. In comparison, DIA can handle nearly 100 arrivals in the same period.

None of the runways intersects and, with more than a 4,300ft separation between runways, as many as three aircraft can land at the same time on parallel runways during bad weather. The runways are equipped with Category IIIb and Cat I instrument landing systems (ILS). Every south approach to the airport has a Cat IIIb ILS system and all other ends have Cat I.

Three centralised de-icing pads, located at the end of each concourse just off the west apron perimeter taxiway, will each accommodate as many as six aircraft simultaneously. Airline workers, work, from pad booms or mobile trucks. Because the pads are located close to North/South Runway 16/34, aircraft will not have to queue after de-icing. Used fluids are collected and piped into storage tanks for future recycling. Each pad has a storage tank able to hold 1.9 million litres (500,000USgal) of liquid.

The runway/taxiway surface-control system has innovative fielding lighting and pavement markings to guide pilots in conditions of limited visibility. All runways and taxiways have been built with centreline lighting. Each runway is constructed with distance-to-go signs, as well as a full complement of mandatory instruction and guidance signs.

Runway-incursion prevention measures include tower-controlled stop bars at all taxiways connecting to a runway. These stop bars include in-pavement red lights as well as L-804 taxi-hold position lights (wig wags). Aircraft hold at these positions until cleared by the controllers. Taxiway clearance bars (in-pavement yellow lights) have also been incorporated at key locations to stop taxiing aircraft at designated locations.

DIA has installed an electronic airport-mapping system developed by Arnav Systems. Able to track airport-ground vehicles, its role will be expanded to monitor global-positioning system (GPS)-equipped aircraft. It uses differential GPS to determine vehicle locations and velocities for relay via VHF datalink to all similarly equipped vehicles and a central airport-map display.

Westinghouse Norden Systems Airport Surface Detection Equipment (ASDE-3) is installed and will soon be commissioned. It will be upgraded with the airport-movement area-safety system (AMASS), under development for the FAA by Westinghouse Norden Systems. AMASS uses data from the approach and ground-movement radar to provide runway-incursion alerts.

Snow, severe winds and poor visibility marked DIA's opening. FAA officials note that controllers used ASDE-3 that week to maintain positive control of aircraft on the ground, which they could not see at the extreme ends of some runways 5.5km away. "Without ASDE-3, they would have had to close the airport," says a senior FAA official.

Because of the great distances involved at DIA, two ASDE-3 radar were needed. One of them is located on top of the tower, the other at a remote site on the airport grounds. Eventually, three ASDE-3s are planned for the new airport.

Westinghouse Airport Surveillance Radar and enhanced low-level wind-shear-alert systems (LLWAS), made by Loral are also installed at DIA. The airport hosts the nation's largest LLWAS array. Additional sensors are planned for later installation. When completed, the LLWAS network is claimed to be the largest and most comprehensive airport wind-shear-detection system in the world.

A Raytheon terminal Doppler weather radar, was also commissioned at the new airport in April and air-traffic flow, is supported by a new Tracon on the south end of the airport site.

A month after DIA opened, the FAA issued a report card which noted virtually no operational problems. During the first month, DIA handled 42,000 flight operations with only 245 delays - about one-half of 1%. During the same period at Stapleton in 1994, 3.3% of the operations were delayed.


Michael Boyd, an aviation consultant and DIA critic, says that the FAA claim appears to be bogus. "Thousands of consumers did indeed experience delays at DIA. One must ask if FAA data is being politically altered," says Boyd.

Stapleton handled about 33 million passengers in 1993, while DIA is expected to accommodate 34 million in the first 12 months of operation. That is just the beginning. By 2020, the airport should be able to serve up to 110 million passengers annually.

Sprawling over 137 km2 (53 miles 2 ) of Colorado prairie, DIA is big enough to contain Stapleton, Dallas/Fort Worth International and New York's Kennedy, with room to spare. Wellington Webb, mayor of Denver, says that the technologically advanced airport provides "...a positive solution to the congestion experienced at airports across the country."

Others call DIA "Federico's Folly", in honour of US Transportation Secretary Federico Pe¤a, the former Denver mayor who deftly manoeuvred the airport project through political quagmires.

On hand to help celebrate the opening, Pena thanked all those "...who made the tough decisions and the bold investments that have laid the groundwork for a great future". Pena has dubbed the $4.2 billion centre "the crown jewel" of US airports.

Source: Flight International