
A Delta Air Lines flight attendant made an expensive mistake on Saturday morning when they accidentally deployed an emergency slide on a Boeing 767-300 that had just arrived in Dublin following an overnight flight from Boston.
Delta flight DL155 landed in the Irish capital at around 7:20 am on Saturday following an otherwise uneventful flight, but after the 24-year-old aircraft had arrived at the gate, an emergency slide was inadvertently deployed.
Oh, that's not good .. accidental deployment of the emergency slide on a Delta aircraft at Dublin this morning pic.twitter.com/i6j4oaQRy0
— Michael Kelly (@Michaelkelly707) September 9, 2023
It’s estimated that the cost to replace an emergency slide in parts and maintenance, as well as associated delays, is at least $35,000, although this figure can be much higher for dual-aisle aircraft like the Boeing 767.
Delta confirmed that the emergency slide on the front right-hand side door was accidentally activated during the disarming procedure.
Boeing 767 doors are rather unusual in that they open upwards into the interior of the aircraft. The slide arming mechanism is very close to the door opening handle, which also goes in an upward motion.
This might come as a surprise, but inadvertent slide deployments or ISDs, as they are known in the industry, are a regular everyday event. According to aircraft manufacturer Airbus, there are around three ISDs worldwide every day, and four out of five of those occur on aircraft arrival.
Flight attendants are to blame for around 65% of ISDs, and so-called ‘human factors’ such as fatigue or lack of concentration are often the primary cause of an accidental slide deployment.
As well as the cost, ISDs are a big concern for airlines because they pose a very serious injury risk – especially to ground workers who could be hit by an inflating slide.
The vast majority of ISDs occur at the forward left-hand door because this is the door most often used for boarding and deplaning, and the ISD occurs when the flight attendant goes to open the door without first disarming the slide.
In the case of the Delta incident on Saturday, it looks like a crew member may have accidentally moved the door handle. A similar incident occurred on a British Airways jet in June and there was another almost identical ISD on a British Airways plane in January.

Mateusz Maszczynski honed his skills as an international flight attendant at the most prominent airline in the Middle East and has been flying throughout the COVID-19 pandemic for a well-known European airline. Matt is passionate about the aviation industry and has become an expert in passenger experience and human-centric stories. Always keeping an ear close to the ground, Matt's industry insights, analysis and news coverage is frequently relied upon by some of the biggest names in journalism.
I think DL154 is the BOS-DUB and DL155 is the DUB-BOS. (I looked it up because I didn’t realize Delta had this flight!)