On the 10th of September 2024, an Airbus A350 took the tail off of a Bombardier CRJ at Hartsfield-Jackson Atlanta International Airport in Georgia, USA.

Delta Air Lines flight 295 was a scheduled international service from Atlanta to Haneda Airport in Tokyo, Japan being flown that day by an Airbus A350-941 registered in the US as N503DN. There were 15 crew members and 221 passengers on board.

The Airbus A350 is a long-range wide-body twin-engine airliner that weighs about 255,000 pounds (~115,700 kilos) empty. Its most distinctive feature is a black windshield mask around the cockpit window frame, which I can’t help but think of as slutty eyeliner (in a good way). It also has really big wings.

Delta Connection flight 5526, operated by Endeavor Air, was a scheduled domestic service from Atlanta to Lafayette Regional Airport in Louisiana, being flown that day by a Bombardier CL-600-2D24 (CRJ-900) registered in the US as N302PQ. There were three crew and 56 passengers on board.

The CRJ-900 is a twin-engine, short-to-medium-haul regional airliner that weighs about 48,000 pounds (~21,800 kilos) empty. The most distinctive feature of the CRJ is a tall T-shaped tail, like an oversized spoiler bolted onto a Honda Civic.

Needless to say, it was hardly a fair fight.

There are five parallel runways at Atlanta, all of which run east-west to allow for simultaneous takeoffs and landings. Atlanta’s control tower is the tallest in the US in order to allow the air traffic controllers to oversee the entire length of all five runways. Atlanta Ground is responsible for all ground movements with the exception of the active runways. Atlanta Tower is responsible for all inbound and outbound flights and thus controls access to the active runways.

The CRJ had a relatively short route: They needed to travel north from the apron to Taxiway F to join Taxiway E, which is parallel to the runways. On Taxiway E, the CRJ would turn into Taxiway H which runs along the bottom of runways 8 Right and 8 Left, and immediately hold short (wait for clearance before entering) for their departure from runway 8R.

Normally, larger aircraft such as the Airbus A350 would take off from the longest runway, 9L/27R with 12,390 feet of concrete (3,776 metres) on the south side of the airfield. But 9 Left was closed for construction and so the flight was departing instead from the next longest runway, 8 Right, on the north side of the airfield; the same runway as the CRJ was waiting to enter.

The Airbus pushed back from the gate early and the crew got the all clear to taxi north towards the runways. The captain thought about how odd it was to be back at the north side of the airfield, as he hadn’t been there since he’d started flying the A350. He warned the first officer that taxi operations on the north side feel a bit different and that if there were any questions or issues, just say so and they would stop the aircraft and figure it out.

The ground controller told them to continue to Taxiway G and hold short of Taxiway F for the CRJ.

At this point, the CRJ was on the far end of the airfield, on Taxiway F. The CRJ entered Taxiway E, the one which runs parallel to the runway, and was asked to hold short at Taxiway H and switch frequency to Tower.

The captain commented later that it was a slightly awkward routing because there was a Frontier aircraft in the way. “They don’t usually make us jig and jag that big airplane around.” The Airbus was cleared to enter Taxiway F, where they also turned onto Taxiway E. The controller told the flight crew to follow the CRJ on Taxiway E and monitor the Tower frequency. The CRJ was so far ahead of them, neither pilot considered it to be a factor.

At that moment, the crew of the Airbus noticed a navigational alert message. They weren’t sure it was important but they needed to find out before embarking on that long trip to Tokyo. The first officer called Ground to say that they needed to stop and speak to maintenance. The controller confirmed that they should stay on the Ground frequency but told them that they could not stop there; they should continue straight, past the intersection to Taxiway H, and then they could hold short at the entrance to Taxiway V where they would be out of the way.

This navigation isn’t really as complicated as it sounds; here’s a top-down view of the routes with the CRJ in orange and the Airbus in blue.

The CRJ turned at the intersection for Taxiway H and stopped at the hold short line, or actually, about 56 feet short of the hold short line.

The captain taxied the aircraft towards the end of Taxiway E. He wasn’t too worried about the alert. “We’re going to Tokyo, we had a 14-hour flight, the five or ten minutes it’s going to take to deal with maintenance is not an issue with me.”

He remembered that it could get tight at the end of Taxiway E and that aircraft could come quite quickly around the corner from the opposite direction, from Taxiway V to Taxiway F. “I all of a sudden started going well, how far down there can I get before the left wing starts to be a problem for ripping around the corner…and when I say rip around the corner, people come around that corner pretty fast. They come up over that hill and because it’s a hill, they got the power up and they get up and they don’t get it back and they’re — I mean, they’re doing a good 15-20 knots coming around that corner, most times, Southwest even faster.”

(I laughed at that little jab at Southwest Airlines)

So the captain was watching their position, making sure that their left wingtip wouldn’t be in the way of any oncoming aircraft. I should note that the flight crew can’t actually see the wingtips from their seats in the cockpit. Even if they got up and looked out of the rearmost windows, they would struggle to see if the wingtip was clear of any obstructions, so it’s important to be positioned correctly on the centreline, especially on a small taxiway. “The basic fact is I became so worried about my left wingtip, I forgot about the right wingtip.”

The first officer was staring at the navigational display but Taxiway V was not displayed. The first officer remembers trying to figure out exactly what their clearance was, and then spotted the taxiway on the moving map.

With the captain looking towards the left and the first officer checking their navigation, neither pilot noticed as they passed behind the waiting CRJ until the Airbus right wingtip smashed into the CRJ’s tail.

The first officer of the CRJ remembered that there was some sort of vibration, which he compared to the start of wake turbulence, and then there was a jolt and the sound of multiple warnings and dings in the cockpit.

At the same time, Tower called them to line up and wait on the runway.

The CRJ captain told the first officer to decline the clearance.

The first officer, unsure what had just happened, asked Tower to standby. Both pilots stared at the cockpit displays and a series of hydraulic system caution messages, still not sure what had happened, even while someone on the radio started to talk about a collision.

The first officer remembered the moment. “I think it was another aircraft asking Tower what they were going to do about the collision and we’re just sitting there, we know something happened. And at that point we realised, okay, we’re the ones involved in that collision.”

The Airbus first officer said of the impact, “I thought either the gear collapsed or we had run over something.”

The Airbus captain was a bit less prosaic. “Felt the thump, thump, thump, thump and went oh, shit –excuse my French–and stopped the airplane, set the parking brake and told the co-pilot, we got to call ground.” He seemed to be the only one who immediately understood that they’d collided into something.

None of the passengers were injured; however, the cabin crew member in the CRJ suffered a minor injury.

## Probable Cause and Findings

The National Transportation Safety Board determines the probable cause(s) of this accident to be:

Delta Air Lines flight crew’s loss of situation awareness of the clearance between their right wingtip and the empennage of an Endeavor Air airplane holding on a perpendicular taxiway, resulting in their wingtip colliding with the other airplane’s empennage. Contributing to the collision was the Endeavor Air flight crew stopping too far from the hold short line, resulting in insufficient clearance for the Delta Air Lines airplane to pass.

The CRJ-900 was substantially damaged. The report describes it as “the separation of the vertical stabilizer” which sounds very clinical. In actuality, the Airbus wing literally severed the CRJ’s tail, which hung there attached by the flight control cables, wiring, and a strip of skin.

The A350 was said to have suffered only minor damage; though that looks pretty bad to me, not to mention the embarrassment of the blue paint scrapes and pieces of the CRJ found in the wing when they extended the flaps.

You can read the full report on the NTSB site: Aviation Investigation (DCA24FA299)