Originally Posted by
b1lanc
Citing AVH,
"According to information The Aviation Herald received on Apr 12th 2019
ground tracks reveal the aircraft was dragging its left wing tip for quite some distance on the ground, the ground tracks even suggest the aircraft came close to ground loop.
The aircraft and left wing tip became airborne just ahead of the runway sign, the left wing tip impacted the sign, parts of which became embedded in the left wing tip. The wing also sustained according damage to its underside near the wingtip."
“When we departed… strong roll to the left… as we climbed out,” the pilot told air traffic controllers shortly after takeoff, according to an audio recording from LiveATC.net.
“We were banking… Uncontrolled bank 45° to the left.”
“Turbulence from another aircraft?” the pilot adds.
“I don’t think so. There’s a good crosswind, but we had an un-commanded roll to the left as we rotated.”
The pilot also tells controllers that the aircraft was at that point “flying great”, and he requests clearance to return to JFK, where the A321 landed without incident at 21:09.
“" I was aboard this aircraft. The take off was fast, rather quick and felt short. Then we pitched down and banked right (left wing up) and then left (right wing up) and the back felt to skid out sideways, I was in the window seat just behind the left wing. Then it felt like the pilot pulled the aircraft up manually. He continued to make very strong left and right banks while in the air before we circled back to JFK. He made an announcement that we had a major computer failure, but that he had control of the airplane and that we'll be making an emergency landing."
Given this description of the ground track, a prevailing crosswind from the right, the reported crew comments and the reported passenger observations this event could be the result of something similar to what occurred to the Lufthansa A320 D-AIPW in 2001. If a mis-wiring of the ELAC plug fitting is still possible (can't recall if Airbus modified this subsequently) then a reversal of the PF's aileron control could possibly account for what's been observed/reported.
Imagine the PF establishing a small into wind right wing down input when rotating to counter the expected effect of the right wing rising due to what he described as a "good crosswind". A reversed aileron input would exacerbate the crosswind's effect of raising the right wing with the PF responding by adding a further reversed right wing down input causing the right wing to rise further and the left to start dragging on the ground. Increased drag on the left side pulls the aircraft to the left eventually with the tip off the paved surface and contacting the DTG sign just as the aircraft gets airborne. Once in the air the reduction in drag on the left side after the impact with the sign induces an initial roll back to the right mentioned by the passenger followed by further roll oscillations to left and right that would be bound to occur if the ailerons were operating in reverse to the PF's stick inputs. As with D-AIPW a transfer of control to the other pilot or engagement of the A/P would have caused the reversed inputs to cease allowing the airplane to be controlled normally and leaving the appearance to the crew of having experienced an uncommanded roll to the left on take-off (which indeed it would be).
There was also at least one instance of spoiler actuators being incorrectly locked out that led to a similar flight control response on rotation, but in that case the uncommanded roll effect persisted throughout the flight which does not accord with the pilot's statement that the aircraft was subsequently "flying great"..
ELAC
https://aviation-safety.net/wikibase/wiki.php?id=147094
https://www.bfu-web.de/EN/Publicatio...ublicationFile
https://aviation-safety.net/wikibase/wiki.php?id=147070
https://assets.publishing.service.go...12__G-KMAM.pdf