Episode 58: Swissair Flight 111

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By the time Swissair Flight 111 reached its cruising altitude in the evening hours of September 2, 1998, there was no reason to expect anything other than a safe flight. Less than an hour after takeoff, a strange smell in the cockpit indicated something was wrong— and it would take more than four years before the world would know exactly what that was. In this week's episode of Take to the Sky: the Air Disaster Podcast, Stephanie walks us through what happened and what we learned from a disaster whose legacy shaped aviation as we know it today.

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Who Were the Passengers on Swissair Flight 111?

As Swissair Flight 111 prepared for departure on September 2, 1998, it was a night like any other— especially for many of the passengers onboard. Nicknamed the UN Shuttle, this particular route was very popular with officials from the United Nations; departing from New York City's JFK International Airport, where the UN Headquarters is located, it was bound for Geneva, Switzerland, where the second-largest UN center is located, and several high-profile employees took their seats as some of the 215 passengers preparing for their transatlantic journey.

Ingrid Acevedo, the public relations director for UNICEF, was among them, as was Pierce Gerety of the United Nations High Commission for Refugees and Yves De Roussan, a UNICEF adviser. Jonathan Mann, the former head of the World Health Organization's AIDS program, and his wife, AIDS researcher Mary Lou Clements-Mann, buckled their seatbelts for the trip along with them. And although it was nick named the UN Shuttle, there were many other people onboard preparing for very different trips. Klaus Kinder-Geiger lived in Long Island, New York, but was heading to Italy to give a speech before returning to Geneva to work at CERN; he was a top physicist working on a computerized model of large nuclei at high energies. Denis and Karen Malliet were heading to France with their 14-month-old son, Robert; they were engineers, and this trip was exciting for them because it would be the first time Robert met his paternal grandparents. Tara Nelson was on her way to France to be present when her sister gave birth. Roweena Lee White was heading off to Geneva to start pastry school. And they were just some of the people sharing a pressurized ride high above the world as they embarked on vacations, business trips, or a little bit of both.

Swissair Flight 111 Plane

Swissair Flight 111 was scheduled for a comfortable ride on a McDonnell-Douglas MD-11. The MD-11 is a tri-jet wide-body airliner featuring three Pratt and Whitney engines, a stretched fuselage to accommodate more passengers than previous designs, and a glass cockpit: on this plane, the cockpit design is called the Advanced Common Flightdeck, which featured an Electronic Instrument System, a dual Flight Management System, a Central Fault Display System, and GPS. For passengers in the first class and business cabin, they also had access to a state-of-the-art entertainment system that introduced movie watching, shopping, and games to the flight experience.

Swissair Flight 111 Flight Crew

Captain Urs Zimmermann was 49-years-old and had been flying since he was 18, when he started flying recreationally. In 1967 he joined the Swiss Air Force as a fighter pilot, and he qualified as a first officer for Swissair in 1971. He was upgraded to captain in 1983 on the DC-9, and he flew as the captain in command on the MD-80 and the Airbus A-320, when he was also an instructor pilot, before transitioning to the MD-11 in June 1997. He was also an instructor pilot on the MD-11; he was known for being very detail-oriented, especially with regard to briefings about how to use checklists, and he was also known to quiz his students before, during, and after their experiences in the simulator. Captain Zimmermann was recognized for creating a friendly and professional atmosphere in the cockpit, and his colleagues said he worked with exactness and precision.

He was joined by First Officer Stefan Lowe, who was 36 years old on the night of the flight. First Officer Lowe shared Captain Zimmermann's Swiss Air Force background; he served from 1982 until 1990, and he joined Swissair in 1991 while still remaining a part-time fighter pilot for the Air Force. He was a first officer on the MD-80, Airbus A320, and then the MD-11- just like Captain Zimmerman. The accident report provided a glowing description of his manner and capabilities; it said, "He was considered to be experienced, well qualified, focused, and open-minded in performing the duties of a first officer. His cockpit discipline was described as ideal. He was described as a partner in the cockpit, with a quiet and calm demeanor; he was assertive when appropriate."

Swissair Flight 111 Crash Sequence

Flight 111 departed at 8:18 PM on a route that would take it up toward Canada, over Greenland, and above continental Europe and on to Geneva from there. Takeoff was on time and normal, and there were no issues at 9:00 PM, as the plane approached its cruising altitude at Flight Level 33, which is 33,000 feet. The cockpit voice recorder picked up the sounds of conversation as well as the sound of cutlery; the flight crew was served dinner at that time.

At 9:10 PM, as the plane flew northeast toward Halifax, Canada, Captain Zimmermann and First Officer Lowe started to smell something strange, and it was accompanied by their initial observation of smoke in the cockpit. Although this might immediately sound concerning, they realized it seemed to be connected to the air conditioning system in the cockpit, and they very quickly confirmed there was no smoke or corresponding strange smells coming from the passenger cabin. Four minutes later, at 9:14, the crew contacted air traffic control and said, "Swissair one eleven heavy is declaring Pan Pan Pan. We have smoke in the cockpit, uh request immediate return to a convenient place, I guess Boston."

If mayday being a universal declaration of an emergency, pan pan is a step below that: think of it us a universal sign of urgency. What they pilots were trying to communicate was that there was a serious issue on board, but the plane, the crew, and the passengers were not necessarily in immediate danger.

Air traffic control cleared Swissair Flight 111 to Flight Level 310 and asked if they would prefer to land at Halifax instead of Boston; Boston was more than 300 miles away whereas Halifax was about 60 miles from their location, so it was much closer given that they were experiencing an urgent situation onboard. The flight crew confirmed that Halifax would be desirable, and they were cleared to descend to Flight Level 290. A nearby British Airways flight that had heard the pan pan call offered to give the flight crew a weather report as they prepared for their landing, letting them know there were some broken clouds and low winds in the area. The crew also put on oxygen masks at that time.

The smoke in the cockpit may have been concerning to the flight crew, but it was the amount of fuel on board that dominated their conversation with air traffic control. The plane had only been in the air for about an hour, which means they were far too heavy to safely land in Halifax, which was coming up quickly. By 9:19 they were just 30 nautical miles from the airport, and after being cleared to descend to 8,000 feet there was no way they were going to be able to land so fast; it would have been too quick a descent, and the plane was still too heavy. The flight crew told air traffic control they needed more time for a safe landing, and they were given a new heading that would buy them some more time to make their descent. Air traffic control asked the flight crew to confirm the number of people on board as well as the amount of fuel remaining; while the flight crew did not confirm the number of people, they did say they had 230 tons of fuel, which was a misspeak: the entire weight of the plane was 230 tons. The flight crew asked if they could start dumping fuel to reduce their weight, to which air traffic control said, "Turn to the left heading of two zero zero degrees and advise me when you are ready to dump. It will be about ten miles before you are off the coast. You are still within about twenty-five miles of the airport." The flight crew confirmed that they were turning to the left; at that point, the CVR picked up the sound of the flight crew discussing the air conditioner smoke checklist.

At 9:23, air traffic control gave Flight 111 a new heading to turn them more toward the left and let them know they would be over the ocean for their fuel dump within 15 nautical miles and that they would still be close to their airport in case the urgent situation turned into a full emergency. The flight crew acknowledged receipt of the new heading and relayed that they were at 10,000 feet. Just twenty seconds later, the flight crew contacted air traffic control, saying, "Swissair one eleven. At the time we must fly manually. Are we cleared to fly between eleven thousand and niner thousand feet?" Air traffic control responded that they could block between 5,000 and 12,000 feet, giving them more clearance than requested.

Seven seconds later, both members of the flight crew were picked up simultaneously. One said, "Swissair one eleven heavy is declaring emergency," as the other said, "We are between twelve and five thousand feet we are declaring emergency now at time zero one two four." Ten seconds later, there was another transmission from the flight crew: "Eleven heavy we starting dump now we have to land immediate." Air traffic control responded with, "Swissair one eleven just a couple of miles I'll be right with you," to which the flight crew responded, "Roger. And we are declaring emergency now Swissair one eleven." Fifteen seconds later, air traffic control said, "Swissair one eleven you are cleared to ah commence your fuel dump on that track and advise me ah when the dump is complete." 25 seconds after that, air traffic control repeated their transmission. Swissair Flight 111 never responded.

Swissair Flight 111 Rescuers and Volunteers

In Peggy's Cove, off the south shore of Nova Scotia, it was 10:25 PM local time, and Bob Conrad was dozing off on his couch. He was a tuna fisherman, and his nap was disrupted by the sound of an explosion outside of his house. Not long after that, he heard reports that there had been a plane crash nearby. He told his wife Peggy he was going to get in his boat and help with the rescue. On what was described as a miserable rainy evening, Bob found himself floating in his boat in the midst of a horror show of debris that was illuminated by the glow of flames. He tried to haul what he could see onto the boat, first attempting to grab a suitcase that was too heavy for him to safely load on his boat. He pulled in a jacket that was sticking out of it instead. Next, he reached out to bring in a child's doll that was floating in the water— but it wasn't a doll.

Bob recovered the body of 14-month-old Robert Maillet, who was traveling with his parents to France. He said, "I brought him aboard and later found out he had the same name I had — he was a Robert and I was a Robert. So I just cared for the body and wrapped it in a blanket."

Scott Hubley had just finished fishing for the day, and like Bob Conrad he rushed back to the water to be part of what he hoped would be a rescue effort. He didn't even bother to put socks on before pulling on his boots and returning to his boat. He said, "It was a black old night. We started picking up luggage, clothes, food trays — whatever's on a plane — and then it got more graphic. Stuff you've never seen before, but you knew what it was."

Vic Gerden led the investigation for Canada's Transportation Safety Board, but there were 1,500 people involved in initial search and rescue efforts. Those numbers counted members of the coast guard, the crew of Canadian warships, local fisherman, and community members with boat access and a desire to do all they could to aid the efforts. It was clear very quickly that the only mission would be one of recovery; volunteers brought in stuffed animals, pocketbooks, photos, and clothing that were found floating among the waves. One fisherwoman, Ellen Hayes, said, "You want to see these belongings returned to loved ones. It isn't much, maybe, but it's what we can do."

Swissair Flight 111 Victims

There were 229 people on Swissair Flight 111, and there were no survivors after it crashed into the open water in Peggy's Cove that night. It would take days to comprehend the magnitude of the air disaster four years before a report would detail what happened, and 39 million dollars to seek the truth.

Chief medical examiner Dr. John Butt was responsible for some of the most emotional and heartbreaking aspects of the recovery: he was charged with identifying remains and reuniting them with family members. It was an unfathomable task; the plane broke into what investigators would eventually determine to be two million pieces. The bodies of the victims could not withstand the impact with the water any better than the plane could. Dr. Butt said, “Five or 6 days after the crash, my instructions were: ‘If you can see into the fuselage, don’t remove any bodies until we see where they are seated. Wasn’t that naïve. What fuselage? What bodies? What seats?” On September 4, two days after the crash, he stood before 600 family members who had gathered for an update on the search for survivors. He said in an interview that he didn't know what he would say to them when the time came to speak, and as he looked out he could think of just one thing. Accord to Dr. Butt, “That was ‘I’m sorry to tell you, but none of you will ever see your loved ones again.’” And that created a stillness in the room, and it was done.”

There were 229 souls on board, and investigators found 15,000 body parts as they combed the water. Many of the remains, such as pieces of skin, were just too small to process. DNA testing on all 15,000 remains was not feasible, so it took dental records, hair from hairbrushes, and x-rays to begin identifying the bodies. Many families volunteered DNA samples to be used by labs as they worked through this process. Only one body of the 229 on board was visually identifiable. And thought this work was painstaking and time consuming, it was worth it. One family that perished included a mother, father, and their children— twins. Teams worked to ensure that the remains of each child were correctly and accurately identified. Not all remains were located; in the case of a female passenger, Dr. Butt had to tell a family that all they could find was her left leg and right foot and ankle.

Swissair Flight 111 Crash Investigation

In the immediate aftermath of the crash, air traffic control only knew that the flight crew had declared an emergency— they had not said anything more about it before contact was lost. The investigation determined that the final contact with air traffic control was made at 9:25 PM, but the plane did not impact the ocean until 9:31— six minutes later. There was a lot to uncover about what was going on during those six minutes.

The black boxes— the cockpit voice recorder and the flight data recorder— were recovered, but they did not provide the kind of roadmap to disaster that we're used to hearing; when the flight crew stopped communicating, that coincided with the final data captured on both devices, so there's nothing definitively known about what the crew said to each other or what was happening during those minutes. The only additional clue they had was from the sound of the flight crew's breathing; when they put on their oxygen masks, First Officer Lowe's breathing was measured at 11 breaths per minute based on what investigators could hear from his microphone; Captain Zimmermann's leapt to 25 breaths per minute, a frequency that suggested high stress.

Without data from the black boxes, investigators needed to hear the story from the plane itself, and by some combination of hard work and miracles they were able to recover approximately 98% of the plane's wreckage. That allowed them to reconstruct the plane.

One small bit of good news is that the crash into the water helped to preserve the remnants in a way that wouldn't have been possible on land. I read an interview with aviation reporter David Evans, who made an interesting point: when the plane crashed into the water, the water doused the fire and effectively froze the evidence in time. If the plane had crashed on the ground, it would have continued to burn and likely would have rendered evidence far less useful and led to inconclusive results.

What Caused the Swissair Flight 111 Crash?

Maintenance records didn't indicate anything that could have or should have led to concern. Still, something clearly brought the plane down, and where there's smoke, there's fire— so the investigators started there. Based on their examination of the wreckage, they were able to determine that the fire started toward the front of the plane in the overhead area. They identified and eliminated about 70 potential sources of ignition until they were left with one: they identified evidence of electrical arcing in the wires associated with the in-flight entertainment system. What they discovered is that the entertainment systems had not been properly installed; the wiring caused some kind of a short circuit, which spread quickly through the ceiling of the plane through the thermal acoustic insulation in the fuselage.

It's unknown what was happening on the plane, but it's likely everyone knew something had gone catastrophically wrong— including the passengers, but without question the flight crew in the cockpit. Captain Zimmermann and First Officer Lowe most likely realized that the smoke was from something much more severe than the air conditioning unit when pieces of the cockpit's ceiling would have collapsed on them. There is no CVR data that confirms this illustration, but aviation reporter David Evans had this to say about the moment the crew would have known there was a fire: "I think that the final horror of their grim situation may not have been fully appreciated until the fire in the attic space over the cockpit burned its way through the ceiling panel, and Captain Zimmermann was showered with the charred effects of the fire, the burned plastic, the sudden blast of heat. At that point, I think that that eruption of hot gas and possibly flame into the cockpit pushed him out of his seat, because we do know that he was not in the captain's left seat at the moment the airplane collided with the water."

No circuit breaker ever tripped; the first sign there was something wrong was when smoke was detected in the cockpit, and even then there was no suggestion that there was a warning light on the instrument panel that would have alerted the crew to an electrical problem. They were running through their checklists to troubleshoot smoke related to the air conditioning; this was confirmed by recorded conversation.

The crew was unaware of what they were dealing with as far as the fire was concerned, so investigators looked at whether or not they made the right decision to issue a pan pan rather than a mayday and whether their decision to dump fuel stole too much time away from a potential safe landing in Halifax. Investigators took a hard look at fire detection and suppression measures installed on the aircraft and determined that, because the crew had no idea that fire was even present on the plane, their decision to dump fuel and prepare the cabin for landing was in line with consistent with what they believed would be part of a safe landing. The investigation went a bit further, in fact, to note that even if the crew had understood the severity of the situation, the fire was burning with such intensity that they wouldn't not have been able to land in Halifax. There just wouldn't have been enough time.

Why Did Fire Spread on Swissair Flight 111?

One reason the fire was able to spread as quickly as it did was because of the materials used as part of the acoustic insulation in the ceiling of the fuselage. The report noted that the silicone elastomeric end caps, hook-and-loop fasteners, foams, adhesives, thermal acoustic insulation splicing tapes, and metallized polyvinyl fluoride insulation blanket cover material were all flammable— which means they combined to create a network above the passengers' heads that was perfect for quickly and efficiently moving a fire. Of note here are the end caps, which are connected to the air conditioning system; when those end caps melted and failed, the oxygen within the air conditioning system was available to help the fire burn even faster and hotter.

Swissair Flight 111 Probable Cause

Ultimately, the TSB issued a lengthy set of conclusions that frame the probable cause for the deadly crash of Swissair Flight 111. Listed first among them was this "Aircraft certification standards for material flammability were inadequate in that they allowed the use of materials that could be ignited and sustain or propagate fire. Consequently, flammable material propagated a fire that started above the ceiling on the right side of the cockpit near the cockpit rear wall. The fire spread and intensified rapidly to the extent that it degraded aircraft systems and the cockpit environment, and ultimately led to the loss of control of the aircraft."

Along with 54 other contributors divided into three categories— findings as to contributing factors, findings as to risk, and other findings— the report then issued numerous safety directives and recommendations to every entity involved, including the TSB, the FAA, the NTSB, Swissair, and Boeing, with whom the plane's manufacturer McDonnell-Douglas had merged.

Swissair Flight 111 Legacy

The legacy of Swissair Flight 111 is monstrous in the world of aviation. Of the 23 direct recommendations that would improve flight safety, 20 of them were quickly implemented. As a direct result of the crash:

  • New flammability standards were introduced, and flammable materials were replaced.
  • New procedures for more accurate tracking of specific wire-related problems and anomalies were introduced.
  • Improved power sources for the CVR and FDR were introduced
  • Air crew are now trained to "quickly start planning for immediate landing until they are assured there is no fire threat to the aircraft or occupants" when smoke is detected.
  • Checklists for dealing with smoke were simplified, and better training was created and delivered to flight and cabin crews.
  • The certification process for in-flight entertainment systems was strengthened.

Swissair Flight 111 Cargo

The plane's manifest included a diamond from a Nature of Diamonds exhibition at the American Museum of Natural History in New York, about two pounds of other diamonds, 9 pounds of other jewelry, 100 pounds of cash, and a multimillion-dollar version of Picasso's The Painter. It is unknown to the public whether or not these valuables were ever recovered; while pieces of the painting were reported to have been recovered, there has been much less said about the diamonds. If the diamonds are, indeed, still at the bottom of the ocean, it is illegal to look for them because Nova Scotia has made treasure hunting illegal; additionally, there are human remains that were not recovered, so that part of the ocean is a final resting place for some victims. In fact, Lloyd's of London, the insurer for the diamonds and jewelry, applied for a treasure trove license to look for the items, but families were so angered by that request that they pulled their application.

Swissair Flight 111 Memorial

Most victims' remains are buried at the Swissair Flight 111 memorial, where 25 coffins each containing 100 pounds of passenger remains are buried. Two large stone markers stand not far from the water; one is dedicated to those who worked toward recovery efforts, and another is dedicated to the victims. It reads, "In memory of the 229 men, women, and children who perished off these shores on September 2, 1998. They have been joined to the sea and the sky."

On September 2, 2018, friends and family from around the world gathered in Peggy's Cove at the Swissair Flight 111 Memorial Site in Baywater, Nova Scotia. Reverand Louis Quennell addressed the people who attended, saying, "The lessons of Swissair were many ... One of the lessons taught is that the world can be a very small place. Tragedy touched people in different ways from all around our little blue planet."

Communities can sometimes strengthen in the aftermath of tragedy, and that's what happened within this small Canadian community. Fisherman Bob Conrad eventually met Nancy White, the mother of Roweena Lee. It was her jacket that Bob found floating in the debris; he keeps a picture of her on his piano along with one other: a photo of Robert Maillet, the baby he recovered amidst the wreckage. He also had the chance to meet Robert's grandparents in the months after the plane crash. He said, "what meant a lot to them was simply to hold the hands that had last held their grandson."

Swissair Flight 111 will forever remain part of the fabric of Peggy's Cove and the lives of those touched by a disaster that claimed 239 lives. And for medical examiner Dr. John Butt, while the tragedy continues to weigh on him, he remembers the kindness and compassion of the volunteers and the community at large. In reflecting on Flight 111, he said, “The goodness of people to one another. I think that was what made an impression on me. This was a demonstration of people who really had a focus on something and really wanted to make life better for other people.”

Show Notes:

We start off with a story about a very different air disaster: an Australian flight that was surprisingly forced to quarantine after a delayed takeoff was impacted by new rules at their destination. We wrap up with a discussion on evil pets inspired by Prancer, a chihuahua described by his foster mom as a "Chucky doll in a dog's body." If you have evil pets of your own, tag us on social media with a photo- we would love to meet them (we think...).


Written and produced by: Shelly Price and Stephanie Hubka
Directed and engineered at: Snow Monster Studios
Sound editor: Stephanie Hubka
Producer: Adam Hubka
Music by: Mike Dunn
Swissair Flight 111

Transportation Safety Board investigators look at Swissair Flight 111's fuselage. Source: AP

Swissair Flight 111

Swissair Flight 111 memorial in Peggy's Cove, Nova Scotia. Source: Wikipedia

Swissair Flight 111

The recovered cargo door from Swissair Flight 111. Source: Wikipedia

Swissair Flight 111

The partially reconstructed cockpit from Swissair Flight 111. Source: Global News