DENVER, NOV. 17 -- The pilot of the Continental Airlines jet that crashed in a snowstorm at the Denver airport Sunday had flown only 33 hours and 23 minutes as a captain of a DC9 jet, and the copilot had flown only for 36 hours and 36 minutes in the aircraft. In addition, the plane had moved out of the sequence air traffic controllers thought it was in and at least one other jet had to taxi around the Continental DC9 and took off ahead of it while the Continental plane waited at the end of the runway.
National Transportation Safety Board Chairman Jim Burnett said Capt. Frank Zvonek, 43, had flown only 198 hours in a DC9 and had been upgraded to captain on Oct. 28.
Burnett pointed out that on an Oct. 19 "check flight," which Zvonek was required to complete before he could be qualified as a captain on the jet, his examiner said Zvonek needed "further experience" before he could be rated as a captain.
Burnett said Zvonek completed his last proficiency check Oct. 30. Burnett declined to characterize the experience level of the crew, but he noted that last year the safety board urged commuter airlines not to pair captains and first officers in cases where both were inexperienced.
"We saw that situation in several commuter accidents and thought it might have contributed to a less than optimum operation of the flight," Burnett said.
Zvonek had 12,000 hours flying time and first went to work for Continental in 1969. He was also a Navy Reservist who flew heavy, four-engine transport jets for the Navy, according to a Continental spokesman.
The copilot, Lee Bruecher, 26, completed his proficiency training for the DC9 on Sept. 14. Before joining Continental on July 20, the copilot had flown for Rio Airways of Texas.
Both the pilot and copilot died in the crash.
The Boise-bound jet waited for 23 minutes after it was de-iced until the pilots began the takeoff roll down the runway, officials said today.
Burnett described what he called "an unusual sequence of events" after the jet left the boarding gate. He said the crew did not request a clearance to taxi to the de-icing pad, and as far as air traffic controllers, who could not see the jet through the snowstorm, knew, the jet was still at the gate.
When the crew radioed to the tower for clearance to make its next movement, controllers cleared it to proceed to the de-icing pad, but the plane, which was already at the pad, went to the runway instead. Consequently, Burnett said, controllers were giving takeoff clearances to jets behind the Continental plane, and at least one taxied around Flight 1713 to take off.
Burnett said the investigators do not know how long this unusual sequence of events delayed Flight 1713's takeoff.
A passenger from New Jersey reported seeing ice building on the wings, but crash investigators said they found no evidence of ice on the jet's engine pressure probes, which would have given false engine pressure readings on the gauges in the cockpit.
False engine pressure readings, caused by ice buildup, misled the crew piloting the Air Florida jet that crashed into the 14th Street Bridge in January 1982. That plane, a two-engine Boeing 737, crashed just after taking off from National Airport in a heavy snowstorm.
The safety board found that the Air Florida accident was caused by the crew's failure to use engine anti-ice heaters while on the ground and its decision to take off with snow and ice on the plane's wings.
Crash investigators here recovered flight instruments from the cockpit of the wrecked Continental DC9 and began examining the jet's two engines for damage. A source close to the investigation said the jet's wing flaps were set at 20 degrees, consistent with the proper takeoff position.
After the Air Florida crash, the safety board urged airlines operating in snowstorms to examine aircraft every 20 minutes for ice. But the Federal Aviation Administration (FAA) rejected the recommendation and said there should be no time limit for de-icing other than the requirement that aircraft not take off with frost, snow or ice adhering to wings or propellers.
The safety board later withdrew the recommendation. Burnett said today that the FAA's decision on the issue was correct because aircraft may be operated in weather conditions that require inspections for ice buildup more frequently than every 20 minutes.
Bruce Hicks, a spokesman for Continental, said pilots flying in wintry weather are required to look at the wings for ice buildup every 20 minutes. Continental challenged a report Monday by the FAA that 26 minutes elapsed between de-icing and takeoff and said that the time was four to five minutes shorter.
But Burnett said tapes of conversations between air traffic controllers and the crew show that the pilots requested permission to leave Continental's de-icing pad and head to Runway 35 Left at 1:51 p.m. MST. At 2:12, Flight 1713 was told to taxi into position. At 2:14, the pilots radioed the tower they were at the end of the runway, and 30 seconds later, they were cleared for takeoff by the tower.
The debate over the elasped time became an important issue because the conditions Sunday were just right for ice to accumulate. The temperature was 28 degrees, which produced heavy, wet snow, and the jet was an older model that lacked slats on the front edge of the wings to give the plane additional lift.
Twenty-seven of the 54 survivors remained hospitalized yesterday. A memorial service for the 27 who were killed was arranged by Continental at the University of Denver's Whatley Chapel. A twenty-eighth person died tonight.
Among those killed was William Harkenrider, 42, of Manassas. Harkenrider, a range conservationist with the Bureau of Land Management, was en route to the Boise Interagency Fire Center to develop a training course on fire rehabilitation.
BLM spokeswoman Marta Witt said Harkenrider was one of four agency employes booked on the flight. Makoto Hideshima, 54, chief of records and library at the bureau's Denver Service Center, also died in the crash. Two other employes missed the plane because of snowy road conditions.