32 Years On – What Was Learned From United 811’s Explosive Decompression

(Simple Flying by Sumit Singh)
Yesterday marked 32 years since a United Airlines Boeing 747 lost a cargo door shortly after departing, resulting in nine passenger fatalities. The aircraft was operating Flight 811 from Los Angeles to Sydney with scheduled stops in Honolulu and Auckland.

Simple Flying by Sumit Singh

Yesterday marked 32 years since a United Airlines Boeing 747 lost a cargo door shortly after departing, resulting in nine passenger fatalities. The aircraft was operating Flight 811 from Los Angeles to Sydney with scheduled stops in Honolulu and Auckland when the incident happened.

Quick responses

On February 24, 1989, the Boeing 747-122 experienced a cargo door failure taking off from Honolulu. The explosive decompression that followed blew out several rows of seats on the aircraft.

Sadly, nine people lost their lives following the unexpected incident. However, the crew on board the plane were heralded for their actions amid the chaos. The pilots and 15 flight attendants worked well to avert even greater tragedies.

An Association of Flight Attendants-CWA (AFA) statement seen by Simple Flying highlights how cabin crew swiftly attended to those injured on the flight. The staff secured oxygen masks before clearing debris from the aisles and exits. They then prepared for an emergency landing.

Laura Brentlinger, a United flight attendant serving as chief purser on the service was making her way up the famous spiral staircase of the aircraft when the decompression happened. She was left hanging in mid-air, holding on for her life and digging her fingernails into the carpet to slow her movement toward the gap.

She was just feet from the hole before managing to hook her elbow around the bottom rung of the stairs to the upper deck. After the plane stabilized, Brentlinger led the preparation of the cabin for an emergency landing.

 Bretlinger also previously shared that had the aircraft been any other type, she is not sure if she would have survived. She expresses that the 747 saved her life and she cried when the legendary plane was retired.

Across the galleys

Other members of the crew described how it was in the lower galley. The decompression forced the walls to cave in. In the final moments before landing, certain staff members sitting together on their jumpseats and rehearsing emergency evacuation procedures.

At the moment of the explosion, Curt Christensen, who was also working on board, was facing forward with empty hands, standing partly in the aft service center. He recalled what he experienced when collapsing into the right aisle.

“Immediately the air filled with a hazy smoke and flying debris. I felt a cold wind and sucking if you will, but it wasn’t a sucking. It was like being in the middle of a huge cannon blast, a blast of cold air. There was grey, swirling smoke and debris flying everywhere,” Christensen said, as shared by Confessions of a Trolley Dolly.

“Out of the corner of my eye, as I was being thrown down, I watched ceiling panels fall; door panels and side panels blew off. Big panels fell on people’s heads. It was like an implosion. Everything came down from the ceiling and the walls inward to us.”

The aftermath

Captain David Cronin, and his crew, consisting of First Officer Gregory Slader and Flight Engineer Randal Thomas, returned the 747 to Honolulu, landing 24 minutes after the cargo door had been lost. As a result of the incident, the aircraft also lost two engines and received wing damage. However, the aircraft landed without any further incidents and the flight attendants helped to evacuate the plane in just 45 seconds.

The known flaws in the design of the cargo door latching mechanism were ordered to be fixed within 30 days. The National Transportation Safety Board (NTSB) shares that examinations reveal that the forward lower lobe cargo door had separated during the flight. This caused extensive damage to the fuselage and cabin structure adjacent to the door.

“The National Transportation Safety Board determines that the probable cause of this accident was the sudden opening of the forward lower lobe cargo door in flight and the subsequent explosive decompression,” the NTSB shares in a statement seen by Simple Flying

“The door opening was attributed to a faulty switch or wiring in the door control system which permitted electrical actuation of the door locking mechanisms, which made them susceptible to deformation, allowing the door to become unlatched after being properly latched and locked. Also contributing to the accident was a lack of timely corrective actions by Boeing and the FAA following a 1987 cargo door-opening incident on Pan Am B-747.”

The NTSB also recognized the vital safety role that staff on board played following the loss of the door. Moreover, the crew received the Secretary’s Award for Heroism for their efforts. Altogether, with such a frightening and time-sensitive incident arising, the crew members managed to get 346 people to safety.

The aircraft

According to Planespotters.net, N4713U, the 747 performing Flight 811, first joined United in November 1970. It held Manufacturer Serial Number (MSN) 19875 and arrived straight from Boeing’s Everett site. Following the incident, it was re-registered as N4724U at the end of 1989 and returned to service in 1990.

 

The aircraft would join Air Dabia with registration C5-FBS in March 1997. This airline was a short-lived Gambian outfit, which flew between 1996 and 1998. Following, the carrier’s collapse, the plane was abandoned in 2001 during overhaul maintenance at the state of New York’s Plattsburgh International Airport. Eventually, it was scrapped for parts in 2004.

It was tragic that nine people lost their lives while in the skies on February 24th, 1989. However, thanks to the quick response and the determination of the crew members, further devastation managed to be avoided.