An intricate, two-year ballet between heavy machinery and jets plying a busy airfield debuts this month at LAX when workers start moving one of the airport's four runways.

Around midnight July 29, airport workers will paint large yellow Xs on the southernmost runway, a signal to pilots that it is closed. Then, multitudes of dump trucks, graders and excavators will roll onto the airfield, not far from where hundreds of airliners will continue to take off and land each day.

The first major project at Los Angeles International Airport in two decades aims to improve safety and prepare the airport for a new generation of jumbo jets. Work will begin just as the airport enters its most hectic month of the year, putting pilots, airlines, air traffic controllers — and members of nearby communities — on edge.

"I think delays will be more significant than the original forecasts," Jon Russell, a safety coordinator for the Air Line Pilots Assn., said of the $333-million project to move the runway 55 feet south — closer to the airport's boundary with El Segundo — and build new taxiways.

The impending mix of heavy construction equipment and commercial air traffic at a crowded airport about to lose one-fourth of its runways has officials looking for ways to head off long delays, which could trigger problems at other airports as well.

Things could get especially dicey during foggy weather or if too many planes queue up for the remaining runways. The Federal Aviation Administration recently took the unusual step of suggesting that airlines rework their schedules to cut back their peak-time LAX operations.

And LAX is experiencing its busiest summer in years, with long lines at ticket counters and security checkpoints, packed planes and routinely overbooked flights.

Airport officials say they must begin work on the project now to be ready to reopen the runway in time to handle the Airbus A380 next year. The soon-to-be-relocated runway, one of two that lie south of the terminals, is the only one of the airport's runways wide enough to accommodate the 555-seat behemoth. (The other two runways are north of the terminals. The runways south of the terminals are the longest of the four.)

"It's a tremendous safety improvement. We want to get it done as quickly as we can," said Jake Adams, runway project manager for the city's airport agency.

The agency and federal aviation officials have lobbied the City Council for years to move the runway. But lawsuits by neighboring cities hamstrung the project until December, when Los Angeles agreed to rethink its LAX modernization plans in exchange for the suits being dropped.

The city's airport agency and the FAA have argued that the work would help prevent close calls on the ground between aircraft at LAX, which historically has had among the nation's highest rates of so-called runway incursion incidents.

More than 80% of the close calls at LAX occur on the south side after pilots land on the outer runway, turn right onto a series of taxiways and stop too close to the inner runway, where planes take off.

After construction is complete, pilots will land on the outer runway and turn onto a new center taxiway, forcing them to slow down before they enter a series of secondary taxiways to cross the inner runway.

After the runway reopens in March, officials will start building the center taxiway and connecting it to both runways on the airport's south side with more taxiways.

Until the taxiways are completed in July 2008, things will be even more challenging as workers stitch connectors to the inner runway at night, keeping the runway open during the day.

Moving the southernmost runway is a massive undertaking that required months of planning to reorchestrate 1,800 flights that use the airport each day and to reroute airplanes once they land.

Construction will bring more than 800 truck trips a day, while most of the airport's south side — including its remaining runway — will stay open to air traffic. At night, when much of the major work will take place, many Boeing 747 cargo jets will have to cross the construction zone to access warehouses on the airport's south side.

"We're building something that's 3 miles long, 4 feet deep and 200 feet wide," said Ray Jack, airport operations supervisor at LAX. "It's a huge project."

In periodic briefings with truck drivers and other construction workers about the dangers of driving on an airfield, Jack uses dramatic pictures from a Sept. 27, 1999, accident at LAX involving a Corsair Boeing 747, a pickup and several large dump trucks.

The far right engine on the two-story aircraft smashed into two big-rig dirt haulers — peeling back the cab roof on each like the skin of an orange — and hit a white pickup, flipping it over, after the pilot turned onto a closed taxiway late at night.

No one was hurt. The aircraft, with 321 on board, was taxiing for takeoff.

To prevent such accidents, officials will update pilots on the runway project through periodic bulletins and will block off the site with bright orange fences. Flagmen will be stationed on taxiways to ensure that trucks yield to aircraft. To keep debris from getting sucked into jet engines, mobile sweepers will constantly clean taxiways.

Work will take place 20 hours a day, with contractors simultaneously tearing up the old 11,095-foot runway and building the new one. To break up the existing runway, workers will use a piece of equipment known as a "hoe ram" that stomps on the concrete like a jackhammer on steroids.

Trucks filled with the crushed concrete will make 200 round trips a day, down a road built between the two runways, to a concrete plant on LAX's western edge. There, old concrete will be recycled. An additional 300 trucks per day will bring remixed concrete for the new runway.

Like a concrete layer cake, the new runway will have three sections: 12 inches of lime-treated material on the bottom, 12 inches of low-strength concrete in the middle and 19 inches of concrete on the top. The concrete will be built in 20-by-20-foot squares that will be knitted together with metal bars.

While construction is taking place, controllers must reroute flights that typically would land on the southernmost runway. The FAA used computer models to help figure out how to get the most from the three remaining runways.

Air traffic controllers employed simulations to reassure the airport's 85 carriers that their passengers wouldn't experience major delays as a result of construction.

But some airline representatives are skeptical.

"It's still somewhat of an open question mark from our perspective," said Frank Clark, executive director of the nonprofit organization that represents airlines operating from the Tom Bradley International Terminal.

International carriers, many of which take off around midnight for Asia, fear they could be stuck with a tough choice if too many planes want to use the airport's longest runway, the one next to the one being moved, at the same time: burn precious fuel during a long wait for takeoff or switch to a shorter runway, which could require them to remove cargo.

Airlines are also concerned that during foggy periods, typically from November to February, some flights would have to be rerouted to other airports.

To forestall delays during poor weather and busy times, air traffic controllers worked with the airlines and encouraged them to revamp their schedules.

"We actually distributed to all the airlines our breakdown of anticipated problems during certain time frames, and we emphasized to them, 'You might consider spreading out your schedule during these hours where we have peak traffic,' " said Marv Shappi, operations manager at the LAX tower.

But Clark, who represents carriers in the Bradley terminal, said the 34 airlines he works with haven't revised their schedules because of reassurances from the FAA that construction will cause minimal disruptions. It was unclear whether any of the other 51 airlines have made changes.

If LAX becomes too busy at times, planes awaiting takeoff from other Southern California airports could be kept on the ground to avoid crowded skies. LAX would receive priority as it tries to clear a backup, officials said.

With air traffic down by 20% since the Sept. 11, 2001, terrorist attacks, and with some carriers using smaller jets, officials are hoping that delays at LAX will not climb significantly, despite losing one-fourth of its runways during the relocation.

"Of course there's going to be an impact," Shappi said. "During certain time frames there might be reportable delays, but we don't think we're going to get into any sort of gridlock scenario."

A reportable delay is defined as an arriving flight that is more than 15 minutes late. In the aggregate, on-time arrivals at LAX already have declined somewhat this year.

Surrounding communities also will be affected by the project, which will require aircraft to taxi greater distances and idle longer, temporarily increasing harmful emissions, according to environmental studies conducted for the runway project.

"When they start increasing the number of operations on those other three runways, then the people are going to be upset," said Roy Hefner, a Westchester resident who is on an airport committee that studies noise.

Airport officials and the main contractor that is reworking the southern runway complex, Tutor-Saliba Corp., have promised to reduce noise, emissions and dust by retrofitting construction equipment and continuously watering down the site. The city's airport agency also hired an independent company to monitor requirements to ease effects on the community.

With construction in full swing in a matter of days, air traffic controllers caution that mechanical problems or bad weather could throw off their best-laid plans.

"If there's an aircraft mishap, like someone's gear collapses on the runway, and now we're down to two runways," the FAA's Shappi said, "all bets are off."    from this link