One person was taken to a hospital after the wing of a large moving passenger jet clipped the tail of a smaller aircraft in front of it at about 7:30 p.m. Thursday.
"An incident is considered an accident when there is a loss of life or severe damage, and in this case at least one plane suffered severe damage," NTSB spokesman Peter Knudson said.
Both planes were taken out of service with visible damage. The wing tip of the larger aircraft was bent while the smaller jet's tail was crumpled and bent.
The Federal Aviation Administration will assist the NTSB on the investigation, FAA spokesman Jim Peters said.
Investigators will review recordings of the flight data and cockpit recorders in both jets, as well as recordings of air traffic control conversations and ground radar. They also will interview crew members on both planes, review weather at the time of the accident and conduct physical inspections of both aircraft, Peters said.
The probe could also include drug and alcohol testing, he said.
The NTSB is expected to issue a preliminary report within 10 days, Knudson said, which would not necessarily point to a cause.
The wing of Delta Flight 266, a Boeing 767 headed to Amsterdam, clipped the tail of Atlantic Southeast Airlines Flight 4904, departing for Raleigh-Durham, at about 7:30 p.m., Delta spokesman Trebor Banstetter said. ASA provides regional air service for Atlanta-based Delta.
There were 204 passengers and 11 crew members on the larger plane, 74 passengers and three crew members on the smaller craft.
The Delta jet returned to the gate and ASA passengers were transported by bus to the terminal. Some passengers were rebooked on other flights, while some had to spend the night in Boston.
Passengers said they were jolted, but there was little panic.
Although there was some reports of screaming and crying, the pilots and most passengers remained calm.
In a recording of air traffic control communications, the pilot of the 767 says, "I think we hit the RJ (regional jet) off of our left wing."
"Did he hit you with his tail, his wing?" the air traffic controller asks.
The pilot of the smaller aircraft replies: "Absolutely he did."
One woman was taken to a Boston hospital after complaining of neck pain, said airport spokesman Phil Orlandella.
Jay Copan, 59, of Raleigh, N.C. was on the smaller plane, half asleep, when he was woken by the impact.
"It woke me up. It wasn't that strong, but it was odd. Some people thought we'd run off the runway," he told the Boston Herald.
"The whole plane shook and some people started screaming," Kristian Bille, 46, of Denmark who was on the larger plane, told The Boston Globe.
Contact between airliners on taxiways and runways is rare, said Kevin Hiatt, a pilot and the executive vice president of the Flight Safety Foundation, an independent airline safety advocacy organization.
"Two airplanes coming in contact in this manner on a taxiway is not a real common occurrence," he said. "We see it more often on ramps, with what we call swapping paint."
The only other incident he could think of occurred at John F. Kennedy International Airport in New York in April when the left wing of a massive Airbus A380 operated by Air France clipped a Bombardier CRJ-700 regional jet flown by Comair, spinning the smaller plane nearly 90 degrees. No one was injured.
"What needs to be visited by the FAA and the airports is markings and signage on the taxiways," he said.