Airbus rejects take off at Zürich
On the 27th of October 2023, Edelweiss Air flight WK298B was a commercial flight from Zürich Airport, Switzerland to Faro Airport in Portugal. The aircraft was a twenty-four year old Airbus A320-214 registered in Switzerland as HB-IHY. On board were two flight crew, five cabin crew and 106 passengers.
Zürich Airport has six runways (10/28, 14/32 and 16/34). Generally speaking, during the day with calm winds, runway 14 is used for arrivals and runway 28 is used for departures. However, in the mornings and evenings, to fit in with noise abatement procedures, runway 28 or 34 is used for landings and mostly runway 32 for departures. However, when there are strong (over 8 knot) winds from the west or north, runway 32 is the preferred runway throughout the day, with 34 for heavies. This isn’t particularly relevant to this accident, I just found the breakdown interesting.
Back to the incident. VASAviation has published the interactions between the flight crew and the controller from LiveATC.net in case you want to follow along.
Shortly before 15:00 UTC, the Edelweiss flight crew identified themselves and informed the tower controller that they were ready for departure.
Zürich Tower: Danke Edelweiss 298-bravo. Wind 290 degrees 13 knots gusting 18 knots. Runway 32, cleared for take off.
There we go! 270° is due west so the wind is coming from a west to northwesterly direction and runway 32 is just north of northwest (320°), so we can see why runway 32 was in use!
They started the take-off run and were approaching V1, also known as the Go/No-Go decision point, as it is the maximum speed at which a rejected take-off can be initiated.
From the Airbus Flight Operations Briefing Notes: Revisiting the “Stop or Go” Decision:
Above 100 knots and below V1
The consequence of an RTO (rejected take-off) maneuver becomes more and more critical as the speed increases. Therefore, only very severe conditions should lead to a STOP decision, when the aircraft is at high speeds.
In the high speed segment, the crew should develop a “GO” state of mind. However, the flight crew should never delay a STOP decision, if necessary.
Suddenly, the Airbus skewed hard to the left.
The flight crew immediately regained control to keep the aircraft on the runway and aborted the take-off.
According to Aviation Herald, passengers reported that the aircraft started to shake, with loose items falling through the cabin, and then they felt the brakes.
It may not sound terribly exciting but here’s a video taken by an attributed plane spotter.
The controller called the flight crew as they were still trying to recover from the sudden veer, which wasn’t the most helpful timing.
Zürich Tower: Edelweiss 298-bravo, I see um aborted take-off. Do you need any assistance?
Edelweiss 298B: Stand by, we are stopping on the runway.
This time, the controller quietly waits until they are ready.
Edelweiss 298B: We will vacate the runway straight ahead via golf (Taxiway G)
Zürich Tower: Edelweiss 298-bravo, you can taxi via golf. For your information, we have the… that the Fire Brigade …due to take-off abortion and because of the speed.
Edelweiss 298B: Roger, thank you. For the moment, it does look like we don’t need any assistance for the moment.
Zürich Tower: OK, just let me know and in case, they will be ready for you.
Everyone sounds a wee bit stressed out, don’t you think?
Swiss: [this is] Swiss 65-yankee-echo, we are ready for departure.
Zürich Tower: Swiss Six, hold position.
Swiss: Holding position, Swiss Six.
Zürich Tower: Edelweiss 298B? The Fire Brigade [called?] and something– my information is smoking at your…
Edelweiss 298B: OK. I see.
According to media reports, the aircraft was travelling 140 knots ground speed when it aborted the take-off run. The left main-gear tyre blew in the resulting braking action but no one was injured.
Swiss: Is it possible to get a runway inspection before take off?
Zürich Tower: We will do a runway inspection but I will call you back. Stand by on runway, please.
Swiss: Perfect, standing by.
Here is the same video as above at the moment of the left slew, slowed right down:
Six months after the incident, on the 20th of April this year, the Swiss Transportation Safety Investigation Board released a preliminary report. It only gives very basic details; however, it does serve the purpose of confirming that an accident investigation is in progress.
The passengers were asked to contact the airline to book new flights. The aircraft required light repairs but was back in service a week later. There was no update but it seems safe to assume that Swiss 65EY reached its destination eventually.
It appears that at the exact moment that the a/c veers to the left…the tail rudder can be seen moving to the left! Was this a crew input or a system malfunction?
I’m not sure whether the rudder motion is real or an artifact of a low-resolution camera looking some thousands of feet down the runway. I also see something that apparently moves very fast across the runway, from left to right behind the aircraft just as it veers; that could also be an artifact (although it shows up in several consecutive frames), or it could indicate a sudden wind gust (or shift in direction); I wonder whether the A320 taking off in a bit of crosswind would be blown sideways (to the right in the picture) or would weathervane into a gust. If the former, the Pilot Flying might have overreacted. The final report will be interesting — at least if there’s a translation; my non-ecclesiastical German is nonexistent, and I doubt Google Translate will be accurate.
BTW: “The aircraft required light repairs but was back in service a year later.” According to the date given at the top, a year from the incident is still five months in our future.
Argh! I meant a week. Some weeks do feel like years, to be fair!
We previously discussed an aircraft veering sharply during take-off at https://fearoflanding.com/accidents/fatal-crash-at-lukla/ .
If an A320 could be blown sideways, they’d require tie-downs when parked on the apron—sitting on its main gears, there should be enough friction to prevent that. The weathervaning is more likely; can a strong gust pushing the vertical stabilizer displace the nose wheel?
My speculation would be that the pilot tried to control the rudder, but somehow the nosewheel steered. Is that even possible on an A320?
I admire how the pilot compensated, coming out of that rallye-like S-turn fairly aligned with the runway. The passengers in the back row had an experience they won’t ever forget!
I’m always impressed that the airports routinely roll the fire trucks on aborted take-offs. The brakes need to convert considerable kinetic energy to heat during a short distance, and they get so hot that they sometimes burst into flames. Imagine if that happened on your car!
I suspect that a rolling aircraft can be put off by wind where a fixed one can’t be moved significantly. Consider what happens if the aircraft leans more heavily on the downwind edges of its tires; if it’s fixed it won’t go anywhere absent a gale, but if it’s moving would the off-balance wheels tend to carry it off-track? (It might stay pointed directly ahead but move at an angle to the intended path.) I don’t know enough about the behavior of ~30-ply tires under side stress to be sure, but I wouldn’t assume there would be no effect.
Would an aircraft this size carry some up aileron on the upwind side to counter any tendency to lean away from the wind? I don’t know whether this is standard in a crosswind, and if so whether pilots are trained to use rudder or more aileron in gusts. It will be interesting to see any details about control inputs (if recoverable from the “black box”) in the final report.
“The aircraft required light repairs but was back in service a year later.”
According to the VASAviation video, the aircraft was back in service after 7 days.
Yes, I meant to say “a week” but apparently my brain broke. Thanks.