Swissair Flight 111 (SR-111, SWR-111) was a Swissair McDonnell Douglas MD-11 on a scheduled airline flight from John F. Kennedy International Airport in New York City, United States to Cointrin International Airport in Geneva, Switzerland. This flight was also a codeshare flight with Delta Air Lines.
On September 2, 1998 the aircraft used for the flight, registered HB-IWF, crashed into the Atlantic Ocean southwest of Halifax International Airport at the entrance to St. Margarets Bay, Nova Scotia. The crash site was 8 kilometres from shore, roughly equidistant between the tiny fishing and tourist communities of Peggys Cove and Bayswater. All 229 people on board were killed.
The resulting investigation by the Transportation Safety Board of Canada (TSB) took over four years and cost CAD$57 million (at that time approximately US$39 million). The organization concluded that flammable material used in the aircraft's structure allowed a fire to spread beyond the control of the crew, resulting in the loss of control and crash of the aircraft.
Prior to the crash, Swissair 111 was known as the "U.N. shuttle" due to its popularity with United Nations officials; the flight often carried business executives, scientists, and researchers .
The aircraft and its crew
The aircraft, a McDonnell Douglas MD-11, serial number 48448 registered HB-IWF, was manufactured in 1991 and Swissair was the only operator. The airframe had a total of 36,041 hours. The three engines were Pratt & Whitney 4462s. The cabin was configured with 241 seats (12 first-, 49 business-, and 180 economy-class). First- and business-class seats were equipped with an in-flight entertainment system.
The standard crew of MD-11 is a flight crew of a captain and a first officer, and a cabin crew of a maître de cabine (M/C - purser) and 11 flight attendants. All personnel were qualified, certified and trained in accordance with Swiss regulations, under the Joint Aviation Authorities (JAA).
Delta sold the tickets of 53 of the Swissair passengers as part of a codeshare arrangement . Since Air Canada was on strike at the time, some passengers who would have flown on Air Canada instead flew Swissair 111
At 22:10 Atlantic Time, cruising at FL330, or 33,000 feet (10,058 m), the flight crew Captain Urs Zimmermann and First Officer Stephan Loew, smelled an odour in the cockpit and determined it to be smoke in the air conditioning system. Four minutes later, the smoke was visible and the pilots began considering a diversion to a nearby airport for the purpose of a quick landing. At 22:14 AT the flight crew made a "pan-pan" radio call, indicating that an emergency exists but there is no immediate danger to the aircraft, and requested a diversion to Boston's Logan International Airport (300 nautical miles away), but was instead directed to the closer Halifax International Airport in Enfield, Nova Scotia, 66 nm (104 km) away. The crew then put on their oxygen masks and began descending.
At 22:19 AT the plane was 30 nautical miles (56 km) away from Halifax airport, but required more time to descend from its current altitude of 21,000 feet (6,400 m). At 22:20 AT the crew informed ATC that it needed to dump fuel, and was subsequently diverted away from the airport. According to the checklist In case of smoke of unknown origin, the crew shut-off the power supply in the cabin, which caused the recirculating fans to shut off. This induced the fire, by a vacuum phenomenon, to spread back into the cockpit. At 22:24 AT, the crew declared an emergency. Aircraft systems, such as lighting, flight instruments, and the autopilot began to fail and as a result the crew slowly lost any means of successfully flying the aircraft. According to readings from seismographic recorders in Halifax and Moncton, the aircraft struck the ocean at 22:31 AT. The crash location was approximately 44°24'33?N, 63°58'25?WCoordinates: 44°24'33?N, 63°58'25?W, with 300 metres' uncertainty.
Recovery and investigation
The aircraft broke apart on impact with the water, and most of the debris sank to the ocean floor (a depth of 55 m or 180 ft). Some debris was found floating in the crash area, and over the following weeks debris washed up on the nearby shorelines.
The initial focus of the recovery was on finding and identifying human remains, and finding the flight recorders, but this proved difficult as the force of impact was "in the order of at least 350 g,"  and the environmental conditions, only allowed recovery along with wreckage.  Only one of the victims was visually identifiable. 147 were identified by fingerprint, dental records, and X-ray comparisons. The remaining 81 were identified through DNA tests. 
The cockpit voice recorder (CVR) and flight data recorder (FDR) were found by the submarine HMCS Okanagan using sonar to detect the underwater locator beacon signals, and quickly retrieved by Navy divers (the FDR on September 6 and the CVR on September 11, 1998). However, both had stopped recording at approximately 10,000 ft (3,000 m), six minutes before impact.
The survey and recovery, dubbed Operation Persistence was TSB guided with resources from the military, CCG, RCMP, and many others. The area was surveyed using route survey sonar, laser line scanners, and remotely operated vehicles to locate items, then recovered (initially by divers and ROV's, later by dredging and trawling).
On October 2, 1998 the Transportation Safety Board of Canada (TSB) initiated a heavy lift operation to retrieve the major portion of the wreckage from the deep water before the expected winter storms began. By October 21, 27% of the wreckage was recovered. 
At this point in the investigation, the cause of the crash was generally believed to be due to faulty wiring in the cockpit, after the entertainment system in the plane started to overheat. Certain groups issued Aviation Safety Recommendations. The TSB released its preliminary report August 30, 2000, but the final report was not completed until 2003. 
The final phase of wreckage recovery by dredging ended in December 1999 with 98% of the aircraft retrieved: approximately 126,554 kg (279,000 lb) of aircraft debris and 18,144 kg (40,000 lb) of cargo.
Two memorials to the victims have been established by the government of Nova Scotia. One is located east of the crash site at The Whalesback, a promontory 1 km north of Peggys Cove. The second memorial is a more private but much larger commemoration located west of the crash site near Bayswater Beach Provincial Park on the Aspotogan Peninsula. Here, the unidentified remains of the victims are interred.
In September 1999 Swissair and Boeing offered the families of the passengers full compensatory damages. This was rejected in favor of a $19.8 billion suit against Swissair and DuPont, the supplier of Mylar insulation sheathing. A US federal court rejected the claim in February 2002.
A number of notable individuals died in this accident, including Jonathan Mann, former head of the WHO's AIDS program; Mann's wife, AIDS researcher Mary-Lou Clements-Mann; Pierce J. Gerety Jr., UNHCR Director of Operations for the Great Lakes Region of Africa, who was on a special mission for U.N. Secretary General Kofi Annan to the Democratic Republic of the Congo to attempt to negotiate a peace accord with Laurent Kabila in an erupting regional war; and Joseph LaMotta, son of former boxing world champion Jake LaMotta,   The crash destroyed a number of works of art, including a piece by Pablo Picasso.
After the crash, the flight route designator for Swissair's New York-Geneva route was changed to Flight 139.
Since the crash there have been many television documentaries on Flight 111, including episodes of disaster shows like History Channel's Disasters of the Century, National Geographic's Air Crash Investigation and PBS's NOVA . NOVA created a classroom activity kit for teachers at schools using the crash as an example of an airplane crash investigation .
In May 2007 the TSB released copies of the audio recordings of the air traffic control transmissions associated with the flight. One of the pilots was reported to have spoken in a heavy Swiss-German accent. The transcripts of these recordings had been released in 1998 (within days of the crash), but the TSB had refused to release the audio on privacy grounds. The TSB argued that under Canada's Access to Information Act and Privacy Act, the audio recordings constituted personal information and were thus not disclosable. Canada's Federal Court of Appeal rejected this argument in 2006, in a legal proceeding concerned with air traffic control recordings in four other air accidents. The Supreme Court of Canada did not grant leave to appeal that decision, and consequently the TSB released a copy of the Swissair 111 air traffic control audio recordings to Canadian Press, which had requested them under the Access to Information Act. Several key minutes of the air traffic control audio can be found on the Toronto Star web site.