Learjet: Model Of Safety?

Veteran pilot Gary Flaugher has flown Learjets for 15 years, has been a pilot for 30 years and has logged more than 30,000 flying miles. He calls the Lear "one of the safest in the sky."

Flaugher said he suspects cabin depressurization was a critical factor in the crash that killed golfer Payne Stewart and five other people, reports CBS News Correspondent Randall Pinkston.

Randall Pinkston/CBS
Cockpit of a Learjet Series 35 (later model than the plane that crashed).

The plane that crashed Monday had been inspected twice since Friday, according to James Watkins, president of Sunjet Aviation, which operated the plane, CBS News Correspondent Dan Raviv reports.

"I would honestly say our inspection process could hardly be more thorough," Watkins said.

The jet Â— a light twin-turbofan business jet that can carry eight passengers and a crew of two Â— is a popular business plane with a safety record approaching that of large passenger jets.

Randall Pinkston/CBS
Aircraft seats 8 plus crew of two. It's designed to cruise at 550 miles per hour at 45,000 feet. Range is 2,000 miles.

It has a maximum cruising speed of 550 mph when flying at 45,000 feet and its range when carrying four passengers and the maximum fuel load of 925 gallons is 2,527 miles.

Learjet Inc., a subsidiary of Bombardier Inc., introduced the production model 35 in May 1973, and the model was certified by the Federal Aviation Administration in July 1974, according to Jane's Aircraft Upgrades. The 35A is the current version of production model 35.

"The safety record is excellent," said Robert Blouin, senior vice president of operations for the National Business Aircraft Association. "This particular aircraft model has been [around] since the mid '70s and they have over 600 in service today."

Randall Pinkston/CBS
One f the most important gauges on the control panel. The cabin controller is supposed to maintain appropriate pressure inside the jet.

The plane is equipped with an oxygen system for emergency use, with crew demand masks and dropout masks for each passenger. It also has a depressurization warning system.

Pilots licensed to fly the jet are trained to recognize and deal with the loss of pressure. Officials are intrigued by reports from the F-16 pilots who trailed the Lear of frost on the jet's windows, a sign of cold outside air being in the cabin.

"There's some sign of moisture in the cabin," Blouin said. "The conjecture is they had a loss of pressure."

Randall Pinkston/CBS
This valve must be in the 'on' position in order for the Learjet to supply emergency oxygen.

Flaugher said at 40,000 feet, someone could survive a loss of cabin pressure without oxygen for a maximum of only 15 seconds.

"If it's explosive depressurization, you got 30-degree temperature coming in and all the air is rushing out," Flaugher said.

"You got to maintain control of the aircraft and have the mind-set to put your mask on and make your descent."

More from CBS News