A Delta Air Lines flight en route to Michigan from Keflavik, Iceland diverted to Montréal after losing cabin pressure on 2 September 2025.
Delta Air Lines flight DL179, operated by a Boeing 757-200, was en route to Detroit Wayne County Metropolitan Airport (DFW).
The aircraft was performing a scheduled transatlantic service from Keflavík International Airport (KEF).
Delta Air Lines DL179 Keflavik-Michigan
As the flight approached Goose Bay, Canada on flight plan track flight crew experienced a loss of cabin pressure. An emergency descent to 10,000 feet was initiated.
Following the descent a precautionary diversion to Montréal, Canada was carried out. The flight landed on runway 24L Montréal–Trudeau International Airport (YUL) approximately two hours after leaving cruising altitude.
According to a subsequent Canadian TSB report, flight crew had noted a rise in the cockpit temperature and adjusted the left-hand pressurisation pack accordingly.
Shortly after the adjustment, the aircraft’s right-hand pack failed. This was followed in rapid succession by the failure of the aircraft’s left-hand pack.
The flight crew executed an emergency descent and the passenger oxygen masks deployed. During the subsequent diversion to Montréal, the right-hand pack resumed normal operation. The aircraft’s left-hand pack remained inoperative.
Flight & Aircraft Data
Flight data shows that flight DL179 had departed from Keflavík International Airport at 8:54 AM local time on 2 September.
Following departure, the flight had set course normally, climbing to flight level FL360 for the transatlantic service to Detroit.
The aircraft was at cruising altitude approaching Goose Bay, Canada when the emergency descent and diversion were initiated.
The aircraft conducting the DL179 service to Detroit Wayne County Metropolitan Airport was a Boeing 757-200, registered N821DX. This is a 21.2 year old aircraft belonging to the carrier Delta Air Lines.
It has been operational service with the airline since July 2015. It began service with Shanghai airlines from its initial delivery from the factory in July 2004.
