DENVER, NOV. 21 -- Continental Airlines Flight 1713 was Lee Bruecher's second trip as a DC9 copilot. He had worked for the airline for four months, having been hired as a reserve pilot in July.

The flight, scheduled last Sunday for 12:25 p.m. local time, was also Bruecher's first trip in the DC9 to Boise, Idaho. It was his first with Capt. Frank Zvonek and his first in snow.

Two days later, as the jet lay in crumpled heaps between two runways, Bruecher's relative inexperience as a pilot of turbo-propelled jets would emerge as an issue. He, Zvonek and 26 others were killed when the jet dropped only a few seconds after lifting off the runway, touched a wing on the grass and flipped forward onto its back. Bruecher is believed to have been flying the plane on takeoff.

Bruecher's newness to the cockpit of the DC9 is not uncommon in today's deregulated airline industry, whose rapid growth has created a huge demand for new pilots. The 26-year-old Texan was one of 20,000 new pilots hired by airlines in the last two years. He was eager to move up to the "majors," and Continental was paying him about $24,000 a year.

When Bruecher, who lived in Houston, drove to the airport last Sunday after having stayed overnight in Denver, it was snowing. Denver had been hit during the night with its first major winter storm of the season. And it had brought high winds and dumped 1 1/2 feet of snow on the city. At the airport, six inches piled up. By dawn, Stapleton's fleet of snowplows was working the airport's four runways. Runway 35 Left was plowed for the last time at 6:25 a.m.

Stapleton is Continental's largest hub, and the airline operates about 275 flights in and out of Denver every day. Continental and United Airlines have battled to dominate the airport, often scheduling flights to the same destination at the same hour. At one point early last summer competition became so fierce that the airport management office stepped in to referee. In June, United employes began wearing lapel pins that, when flipped over, pictured the tail of a Continental jet with a screw through it. Then, they raided Continental's ticket lines in search of passengers.

"We frowned on that," said Norm Avery, a spokesman for the airport office. "We were not going to turn this airport into a combat zone."

Officials here have plans to build a new airport to handle Denver's growing air traffic. In clear weather, Stapleton can accommodate 140 landings and takeoffs an hour. But when it snows, the airport's two east-west runways are rendered virtually useless, and they are often closed.

By the time Bruecher and Zvonek showed up for work to go through their preflight checks, gusting winds had closed the east-west runways. Air traffic would be slowed that day.

Zvonek lived in Carlsbad, Calif., and commuted from San Diego that morning. As captain, he looked over the weather report for each of the three flights he and Bruecher were to make that day. At Stapleton, the temperature hovered just below freezing -- 28 degrees. Winds were from the north-northeast. The Federal Aviation Administration posted an advisory warning of one-eighth inch of snow on Runway Left.

After the flight to Boise, Zvonek and Bruecher were to return to Denver and then go on to Oklahoma City for a layover. Over the next two days, they were to fly seven more legs, covering 3,000 miles, and end back in Denver as Flight 1693 from Rapid City, S.D.

On the plane, a flight attendant approached Zvonek after meeting Bruecher and expressed concern about who would be landing the jet when they returned from Boise. Zvonek assured her he would perform the landing back in Denver.

Zvonek had been made a captain 17 days earlier, on Oct. 28, and had flown 33 hours and 23 minutes in the captain's seat of the DC9. He was ranked 42nd in seniority on a list of 154 DC9 captains based in Denver.

Airline pilots bid for monthly trip assignments, which are awarded on the basis of seniority. Zvonek bid the three-day trip with another senior copilot and was scheduled to fly it five times this month.

A few days before the crash, the airline scheduled Bruecher to fly that first trip so that he could maintain his proficiency.

At 43, Zvonek had logged considerable flight time -- 12,000 hours. He was earning $70,000 a year -- a low salary in the industry. His career progression mirrored the ups and downs of Continental's turbulent past. He began flying as a Navy pilot, on four-engine P3s, and he was a captain in the Navy reserves.

He had worked for Continental since 1969, the year he was hired as a flight engineer. The Denver-based carrier had moved its headquarters to Los Angeles in 1963 and was just entering a period of financial difficulties. As a new pilot, Zvonek started at Continental with 1,400 hours of military flight time -- about half what Bruecher had logged by the time he was hired. Zvonek was promoted to copilot on Boeing 727s in 1977 -- a position he held for five years.

Then, in the early 1980s, Continental was immersed in one of the most bitter takeover bids in aviation history and was ultimately acquired by Frank Lorenzo, head of Texas Air Corp. In 1982, Zvonek was bumped over to the flight engineer's seat, where he monitored gauges and equipment.

In October 1983, Continental's pilots began a strike that ended in the crushing of the union. Zvonek walked off the job. The strike lasted two years. In the meantime, Zvonek opened a restaurant in Carlsbad called the Four Zs.

But he missed flying, and in July 1986 he went back to Continental as a flight engineer. Last April, he went through training and was certified as copilot on the two-person DC9. He made captain in October and had already bid to move up to captain on the 727, which operates with a three-person cockpit crew.

Bruecher began his aviation career when the airline industry was expanding as never before. In 1983, when he began flying for Rio Airways, a commuter airline based in Killeen, Tex., that later filed for bankruptcy, the number of airlines had tripled from 36 in 1978 -- the year deregulation took effect -- to 106.

Bruecher, who needed a total of only 250 hours to meet FAA qualifications to fly as a commercial airline copilot, went to Continental with 3,150 hours of flying experience. He was put through Continental's flight training for the DC9.

Bruecher finished ground school Aug. 11 and simulator training Aug. 29. By Oct. 2, he finished 25 hours of initial operating experience -- a requirement of all pilots before they are certified -- and made one three-day trip Oct. 20-22 that included 11 hours, 36 minutes of flight time and involved 10 landings.

The captain who flew with him on that first trip told investigators for the National Transportation Safety Board that Bruecher was "slow on the flow," meaning his scanning of cockpit instruments was slow -- not unusual for someone new to a particular type of plane.

The pairing of Zvonek and Bruecher is being examined by the NTSB. The safety board closely studied crew pairing in a 1980 crash of a Boeing 727 on Yap Island in the Pacific. The jet was operated by Air Micronesia, owned by Continental. The captain on the flight had flown DC10s, but was bumped down to the smaller B727 because of layoffs. The captain completed his training in the 727, but was not scheduled in it for four months and continued to fly the DC10.

The accident occurred on his first trip in a B727. As he was landing on Yap Island, the NTSB found, the captain reverted to DC10 techniques. No one was killed. The copilot was making his first trip, filling in for a more senior copilot who had called in sick.

The safety board did not write a recommendation addressing pairing of crew members in that accident. But last year, when the issue arose again after several commuter accidents, the NTSB recommended that inexperienced captains not be paired with inexperienced first officers.

NTSB Chairman Jim Burnett pointed to the recommendation a few days after the Continental crash, but stopped short of comparing the commuter accidents with this crash.

The Air Line Pilots Association said the two are not comparable because commuter pilots are less experienced in general, while Continental's pilots, even with relatively little time in the DC9, were seasoned.

Henry Duffy, president of the pilots association, said it is common throughout the industry, because of promotions and changing job assignments, for pilots with relatively little time on various planes to fly them.

"It is not only common, it's almost a bedrock foundation of our industry," he said. "We'll fight very hard for tough standards, but when you are qualified, you are qualified in that seat with any person."

The Future Aviation Professionals of America, which tracks hiring statistics for pilots, has found the average flight experience level of pilots to be steady at 3,000 hours. But the experience level in jets has dropped from 2,300 hours in 1983 to 800 hours in 1985, the last year for which numbers are available.

By the time Zvonek and Bruecher were in the cockpit, the snow was blowing hard and visibility had fallen to one-eighth mile. Continental and United hub operations -- in which dozens of planes arrive in bunches, reload and leave -- were running behind schedule.

The jet making the flight was an old DC9-10 model, a workhorse that had been flying for 21 years. Continental operates 91 of the twin-engine DC9s, including 11 DC9-10 models, which lack slats on the front edge of the wing. Slats were added to later models of the McDonnell Douglas DC9 to assist in gaining lift on takeoffs.

Two years ago, after studying three winter accidents involving the same model, Douglas issued a bulletin to operators reminding them of the DC9-10's tendency to accumulate ice on the wings.

In addition, Douglas cautioned that "ice accumulation on the wing upper surface is very difficult to detect," especially on the upper surfaces of the wings with an ambient temperature above freezing. "It may not be detectable from the cabin because it is clear, and wing surface details show through," the company wrote.

Most of the 82 passengers on Flight 1713 had tickets to fly United to Boise, but the flight was canceled. Among them were six high school students from Melba, Idaho, two graduates and two chaperones returning from a weekend Future Farmers convention in Kansas City.

Flight 1713 waited at Gate D18 for an hour to accommodate the United passengers, then the two pilots radioed to Continental's ground crew that they were going to a de-icing pad. Passengers on the flight said they saw ice on the plane's wings before it was de-iced. The de-icing pad was installed near Continental's hangars last year, and its jets stop there to be sprayed with a hot glycol-and-water mixture before heading to the runway.

Zvonek and Bruecher, according to sources who have heard the cockpit voice recorder tape, remarked on the effectiveness of the de-icing equipment.

Then the confusion began. At 1:51 p.m., Zvonek's voice can be heard on the cockpit voice recorder radioing to air traffic controllers for clearance from the de-icing pad to the runway. The controller could not see the plane, and radioed back, giving clearance to go to the de-icing pad. Neither pilot caught the controller's apparent confusion about the jet's location, and they moved off the pad to the end of Runway 35 Left. Three Continental jets landed on Runway 35 Right, 1,600 feet away.

That afternoon, controllers were alternating departures and arrivals on the two parallel runways, with jets departing on 35 Left and jets landing on 35 Right.

Continental Flight 875, which passed through the de-icing pad after Flight 1713, arrived at the end of 35 Left and was cleared for takeoff while Zvonek and Bruecher waited. Then, another jet, a Delta Air Lines Boeing 767, was brought in on 35 Right.

Soon after, at 2:14 p.m., Zvonek and Bruecher were cleared for takeoff. All told, they waited 23 minutes from the time they left the de-icing pad until they were cleared for takeoff.

Flight 1713 was airborne for only a few seconds. Noises similar to an engine surge are heard on the recorder. Then the final word, an expletive. Then the sound of impact.

Investigators found the first scar in the ground 8,244 feet down the 12,500-foot runway. Next is a light from the plane's left wing. Then the plate window from the cockpit. The final piece, the engines attached to the main fuselage, is 1,090 feet from where the skid began.

A passenger on a later Continental flight told investigators he was growing concerned about the length of time his own plane sat in the snowstorm after leaving Continental's de-icing pad.

The passenger, a flight engineer for Evergreen Airlines, said the jet had had a good de-icing, but he estimated it sat for 15 to 20 minutes and he noticed ice adhering to the front edge of the wings. The passenger said he was just starting to hope that the jet would return to the de-icing pad when the captain came on the air.

Continental Flight 1115 was not going anywhere, the captain said, because the airport had suddenly been closed.