Delta Flight 2311, traveling from Los Angeles to Salt Lake City with 174 passengers and six crew members aboard, experienced an unexpected pressurization issue on September 6 that forced the crew to descend roughly 27,000 feet in about 10 minutes and divert to Las Vegas.
Oxygen masks deployed throughout the cabin as the plane dropped, and pilots could be heard on air traffic control recordings confirming the rapid descent and requesting a direct route to Las Vegas. The aircraft landed safely at Harry Reid International Airport, passengers exited normally, and Delta arranged a replacement aircraft to get everyone to their original destination.
How rare is an incident like this, and what actually triggers it?
Genuinely rare in commercial aviation, according to retired Navy fighter pilot Matthew Buckley, who has nearly 40 years of flying experience. Modern jets maintain cabin pressure equivalent to roughly 6,000 to 8,000 feet even while cruising at 37,000 feet, and a pressurization failure means that artificial environment starts equalizing toward the thinner outside air.
At a typical emergency descent rate of around 4,000 feet per minute, a drop from cruising altitude to a safe 10,000 feet takes about six minutes, well within the 12 to 15 minutes of oxygen most passenger systems supply. The most common causes trace back to either a mechanical fault in the pressurization system itself or gradual structural fatigue building up around window frames, door seals and fuselage joints after thousands of takeoff and landing cycles, which is exactly why airlines run scheduled inspections looking for early fatigue cracks before they become a real problem.
Has something similar happened on a Delta flight before?
Yes, and the earlier case turned out worse for passengers. In September 2024, a cabin pressurization problem aboard a Delta 737-900ER traveling from Salt Lake City to Portland caused several passengers to bleed from their nose and ears, with medical personnel meeting the flight to evaluate ten people once it landed. The FAA opened a routine investigation into that incident, and the aircraft was pulled from service for a day while Delta technicians resolved the underlying issue. That comparison shows the range of outcomes a pressurization event can produce, from Flight 2311’s relatively uneventful diversion to a case with actual physical injuries just two years earlier.
What did it actually feel like inside the cabin during Flight 2311?
Confusing more than anything else, based on passenger accounts shared online afterward. One traveler described the scariest part not being the descent itself but not knowing what was happening, since flight attendants were trying to give instructions through their own oxygen masks in a cabin too loud to hear clearly…