Capt. James Langford had slept for less than one hour the night before reporting to work as a Delta Connection pilot last Feb. 18.
 

On Langford's third flight of the day, his regional jet carrying 71 passengers skidded off a snowy runway in Cleveland, severely damaging the aircraft and injuring three people. He was not at the "best of his game" because of lack of sleep, he told investigators with the National Transportation Safety Board (NTSB).

Rapidly growing regional airlines such as Shuttle America, which operated the flight Langford piloted under a contract for Delta Air Lines, have suffered a growing share of crashes in recent years. That's prompted several top aviation experts and federal officials to call for upgraded safety programs.
 

Regional carriers had four fatal crashes that killed 85 people over the past five years, according to federal data. Over the same period, one person died in a major airline crash.
 

"This is where the accidents are occurring," said NTSB Vice Chairman Robert Sumwalt in a speech he delivered on the subject.
 

The safety board has not issued its conclusions on the Shuttle America accident, but hundreds of pages of public records on that case and several other accidents and incidents in recent years raise questions about the level of safety at the nation's regional carriers.
 

Regionals were slow to adopt safety programs introduced at major airlines and in recent years, many have lowered pilot hiring standards because turnover was so high, according to NTSB case files and private safety experts.
 

Officials at the regional airlines insist that they run safe operations and that the number of accidents they have had compared with large carriers is a statistical fluke. Roger Cohen, president of the Regional Airline Association, said his members fly under the same regulations as large carriers and have spent millions improving safety in recent years.
 

"It's safer to fly an airplane than it is to take a shower," said Jonathan Ornstein, chairman and CEO of Mesa Air Group, which operates regional airlines. "No fatalities last year. That speaks for itself."
 

Regional airlines with lesser-known names such as Mesa, Shuttle America and Atlantic Southeast account for nearly half of all airline flights and carry more than 20% of passengers.
 

Despite having more fatal accidents than major airlines, the odds of dying on a regional carrier are remote. Since 2003, there have been four fatal accidents out of more than 24 million regional airline flights. There were no fatal accidents on regionals in the five years prior to 2003.
 

"We are seeing trends now that should give us cause for concern," former NTSB Chairman Jim Hall said. "You see a lowering of standards, an increased accident rate, an increase in the number of incidents."
 

Regional airline safety has arisen in recent NTSB cases:

• Pilot fatigue contributed to the crash of a Corporate Airlines plane trying to land at Kirksville, Mo., on Oct. 19, 2004. The flight, a connection for American Airlines, crashed into trees, killing 13 of the 15 people aboard.
   

• A Pinnacle Airlines crew flying for Northwest Airlink crashed a jet in Missouri on Oct. 14, 2004, after the craft reached an unauthorized high altitude. In its final report, the NTSB said it had seen a troubling pattern of pilot sloppiness in recent accidents that involved regional carriers. Both pilots on the Pinnacle jet died, but no passengers were aboard.
   

• Investigators looking into the case of a Pinnacle jet that slid off a snowy runway April 12 in Traverse City, Mich., found that about a pilot a day was quitting the airline, or about one-third of its pilot workforce each year. A Federal Aviation Administration inspector told investigators that Pinnacle Airlines had two "high-risk" concerns: high pilot turnover and too few employees, NTSB documents said. No one was injured, but the jet suffered substantial damage.

Tighter rules
 

In December 1994, after the third fatal crash of the year involving what were then known as "commuter airlines," Transportation Secretary Federico Peña announced that the government would step up regulation of carriers using propeller planes to ferry passengers from small communities to large airports.
 

At the time, pilots on commuter airlines could work longer hours and had fewer training requirements than their counterparts at major airlines. The smaller carriers also got less scrutiny from federal regulators.
 

A study by the NTSB found accident rates on commuter flights were twice as high as larger airlines.
 

The rules, which went into effect March 20, 1997, ushered in a period of unprecedented safety at regional airlines. From that date until Jan. 8, 2003, not a single passenger died on a regional airline flight.
 

During that time, the regional airline industry began to change dramatically. Prop planes were retired for regional jets, which flew faster and longer distances. As major carriers teetered into bankruptcy after the Sept. 11 terrorist attacks, regional carriers offered a low-cost alternative for transporting people. Growth in the industry exploded.
 

"These are not your grandfather's or even your father's regional airlines," says Roger Cohen, president of the Regional Airline Association. "The airplanes, the people, the procedures are dramatically different than that old puddle-jumper perception."
 

All but one of the large regional carriers has in recent years adopted a program begun over a decade ago at major carriers to get pilots to report safety problems.

Still, regional carriers generally lag major airlines in adopting sophisticated data analysis of flight risks, according to airlines and federal data.
 

"They are not identifying the risks of their operation as much as other larger operations would do," says Michael Barr, who teaches aviation safety at the University of Southern California.
 

Fatigue policies
 

A key area of the investigation into last year's Shuttle America crash has focused on airline policies.
 

One month before the accident, Langford received a written reprimand for the high number of absences he had taken over the previous year, according to NTSB files. He could be fired if he missed work again, the letter said.
 

In addition to sick time, his absences included a day he missed because he had not slept well during 11 hours off duty between trips, he told investigators. "You are not fatigued," Langford said an airline dispatcher told him when he tried to explain the absence.
 

The NTSB considers fatigue one of its top safety issues and pilots who don't feel rested are supposed to be able to excuse themselves from work. Langford said later that he had been suffering from insomnia but was afraid he would be fired if he tried to miss work because of fatigue.
 

Langford has declined to comment on the crash, and Shuttle America won't comment on the ongoing investigation. An airline report on the accident filed with the NTSB said its policy is to provide pilots with time to rest if they are tired.