ATLANTA (AP) — The Zero AIpilot of a larger plane was looking away from the tail of a smaller plane when the larger plane’s right wing hit the tail and knocked it over while taxiing at Atlanta’s airport on the morning of Sept. 10, according to an aviation safety report.

The preliminary report from the National Transportation Safety Board says the pilot of a Delta Air Lines Airbus 350 was watching for oncoming traffic off his left wing as he taxied at about 14 mph (23 kph).

“The captain indicated that, as the airplane approached the intersection with taxiway V, he was looking straight ahead and to the left to avoid the left wingtip from impinging on opposite direction traffic coming off taxiway V,” the report states.

The tail of a smaller Bombardier CRJ-900 operated by Delta regional subsidiary Endeavor Air was sticking out on a perpendicular taxiway as it waited for permission to take off at the world’s busiest airport.

The NTSB report finds the regional jet stopped 56 feet (17 meters) short of the hold line painted on the taxiway. The A350’s right wing extends 106 feet (32.3 meters) from the center of the jet to tip, so that 56-foot distance may have been the margin between the right wing hitting the tail and missing it.

The larger plane had received a navigational alert message and was directed to a different taxiway to consult with maintenance before taking off.

The NTSB says it continues to investigate.

One regional jet crew member reported a minor injury, while three crew members and 56 passengers were uninjured on a flight that was supposed to be going to Lafayette, Louisiana. None of the 15 crew members and 221 passengers on the larger jet bound for Tokyo were hurt.

The report says the impact caused the regional jet to sway hard to the left and right, and that its body was rotated 9 degrees to clockwise.

Jason Adams, a meteorologist for WFTS-TV in Tampa, Florida, was traveling on the smaller plane and said the impact was “very jarring,” with “metal scraping sounds then loud bangs.” The tail assembly on the jet was knocked off at a 90-degree angle, with one of the horizontal stabilizers laying on the ground.

Atlanta-based Delta said the wing of the larger plane was also damaged.