HARTFORD, Conn. _ Investigators sifted methodically through wreckage at Bradley International Airport Thursday morning, a day after a World War II-era B-17 bomber crashed, killing seven people and injuring seven more.
A team of National Transportation Safety Board investigators were on the runway and surrounding area on the southern end of the airport, reviewing impact marks that the massive Boeing B-17G Flying Fortress, owned by the Collings Foundation, made in the ground and examining the remains of the aircraft.
Officials said that, just minutes after taking off shortly before 10 a.m., the aircraft's pilots reported a problem and said it was not gaining altitude. The pilots also radioed in trouble with the plane's number four engine. The plane then slammed into an airport building before bursting into flames, sending dark columns of smoke into the air that could be seen for miles.
"Investigators are figuring out what's the best way to preserve evidence," NTSB spokesman Eric Weiss said Thursday.
State police officials said there were 13 people aboard the plane _ 10 passengers and three crew members. Seven were killed and six others were injured, they said. A man working at the airport rushed to help after the plane crash and was also injured.
In a Thursday news conference, Hartford Hospital representatives said that the hospital received six patients from the plane crash, many of them arriving within minutes of each other.
By Wednesday evening, three of the patients had been discharged. Two others were transferred to the Connecticut Burn Center at Bridgeport Hospital, and one patient remained at Hartford Hospital by Thursday afternoon.
State police have yet to identify the victims of the crash by Thursday morning, but spent much of Wednesday notifying families. Both state police and the NTSB have scheduled news conferences Thursday afternoon to provide updates on the investigation.
The Simsbury Volunteer Fire Department said two of its members were among the injured, but did not name them. Officials with the Connecticut National Guard said an air guard member was aboard and was injured helping people get to safety.
It could be up to 10 days before the NTSB, charged with investigating serious transportation accidents, files a report on their investigation and another 12 to 18 months before they make any determinations on the cause of the crash.
"Our mission is to determine what happened, why it happened and to prevent it from happening again," said NTSB member Jennifer Homendy.
The intense fire consumed much of the fuel-laden plane. A piece of a wing and the tail were all that was left of the storied bomber known as a Flying Fortress, a celebrated World War II plane that the Collings Foundation uses in its Wings of Freedom vintage aircraft display.
"At about 9:50 a.m. the crew contacted the tower and reported an issue with the airplane. We are looking into that report for further information," Homendy said. "We know that the crew circled back to runway 6 and attempted to land on runway 6."
As it returned, the plane "impacted the instrument landing system stanchions, veered to the right, over a grassy area, over the taxiway and impacted the de-icing facility," she said.
The NTSB could not answer questions about the maintenance of the 75-year-old plane, but said they had requested those records, along with flight records for the plane. The foundation said it was cooperating with investigators.
"I think there is a real need for scrutiny and oversight here ... It's a vintage airplane and it needs to be properly maintained. If there were defects and improper maintenance it is a very strong red flashing light for others flying these planes," said U.S. Sen. Richard Blumenthal, who was quick to call for an investigation into the plane.
FAA records show the plane, owned by the Massachusetts-based foundation, was built in 1944 and is one of 18 Boeing B-17s still registered across the United States. The foundation purchased it in 1986 and reconfigured it from a firefighting plane to its World War II figure.
The plane has twice been involved in accidents. In a 1986 crash in Pennsylvania investigated by the NTSB, the pilot reported trying to land the bomber in a heavy crosswind, and unable to stop, went off the runway, down a ravine and was damaged, records show.
Another accident, not investigated by authorities, in 1995 was reported in a World War II veterans newsletter that said the plane had to land on one wheel when one of its landing gear would not lock into place. During the emergency landing in Iowa, its wing dragged for 700 feet and was damaged.
Maintaining these planes requires specific plans under federal regulations.
Simsbury Airport Manager Bradford Griswold said there are a variety of regulations surrounding the maintenance and inspection of non-commercial aircraft.
Private airplanes are required to have yearly inspections by a certified airframe and power plant mechanic, Griswold said. Those certificates are issued by the Federal Aviation Administration.
The annual inspections are "incredibly" intensive, Griswold said, and pilots must also comply with any airworthiness directives, which may require more frequent inspections for particular aircraft or repair or replacement of specific parts.
But the process is more complicated with historical aircraft, Griswold said.
Historical airplanes _ such as the B-17 that crashed on Wednesday _ are given individual, FAA-approved plans, Griswold said.
Those plans would cover pilot training and maintenance, as well as any other needs specific to the airplane, he said.
"Usually those plans are tailored to that particular aircraft, and approved by the FAA," Griswold said. "They're more custom to the situation, because they don't fit the boilerplate."
Griswold said the process of developing an individual aircraft plan is meticulous.
The FAA "has developed an exceptionally safe and reliable aircraft system in the United States," Griswold said. "They're not ones to generally let things slide. They'll make sure you get your ducks in a row."
