Questions heard with increasing frequency during the first weeks of fruitless searching for Malaysia Air-lines Flight MH370 concerned whether the search would eventually be abandoned, and whether it's possible that we might never know what happened to the Boeing 777 with 239 people on board. There have been occasions when searches were abandoned, but an accident site was discovered by chance. There also are particular aircraft that have yet to be found.
Probably the most infamous concerned the disappearance of Amelia Earhart and her navigator, Fred Noonan, in a twin-engine Lockheed Electra. The last radio call from the airplane was on July 2, 1937, near Howland Island in the Pacific Ocean. In addition to the massive initial search, there were numerous other searches over the years, some of which appeared to have found what some consider to be evidence of the airplane.
On January 30, 1979, a Boeing 707 cargo airplane operated by Varig Airlines took off from Tokyo en route to Rio de Janeiro, Brazil. The airplane was to make a stop at Los Angeles. Six crewmembers were on board. Among the cargo were valuable paintings. The airplane disappeared about 30 minutes after departure. No trace was found.
On November 1, 1965, the crew of a Douglas C-54 Skymaster operated by Argentina's military radioed they had an emergency and were diverting to Puerto Limón, Costa Rica. There was no further contact with the airplane. Searchers recovered pieces of debris from the Caribbean Sea, but couldn't find the main wreckage or remains of the 68 people who had been on board.
On March 16, 1962, Flying Tiger LineFlight 739 disappeared after taking off from a refueling stop on Guam. The Lockheed Super Constellation carried 96 soldiers and 11 crew on a military charter from the U.S. to Saigon, South Vietnam. The U.S. Navy searched an area of 200,000 square miles, but turned up nothing. Crewmembers on a tanker reported having seen what looked like an explosion in the sky at about the time the airplane went missing. The U.S. Civil Aeronautics Board determined that there had been an explosion on board, but couldn't assign a cause. Speculation ranged from sabotage to a fuel accident.
On June 23, 1950, Northwest Orient Airlines Flight 2501 disappeared while on an overnight flight over Lake Michigan. The DC-4 was en route from New York's LaGuardia Airport to Seattle, Wash. The flight had been at 3,500 feet in an area of developing weather. Shortly after 1 a.m., the crew requested a descent to 2,500 feet for weather avoidance. The request was denied because of traffic. It's believed the airplane had a thunderstorm encounter. Some debris and human remains were found, but the main wreckage was never located. There were 55 passengers and three crewmembers on board.
Even today, the NTSB's files cover a few general aviation disappearances in which we're not likely to ever know what happened to particular aircraft, and others in which official searches had ended and wreckage was discovered by chance months or years later.
On August 9, 2008, a float-equipped Cessna 182E departed from a remote lake about 15 miles south of Juneau, Alaska, en route to the Juneau International Airport Seaplane Base. When the airplane didn't arrive in Juneau, it was reported overdue. Both the instrument-rated private pilot and his son, who also was a pilot, were presumed to have been killed. Instrument meteorological conditions were reported along the airplane's anticipated flight path, and no flight plan was filed. The missing airplane's anticipated flight path would have been over about 15 miles of ocean. The terrain around the Juneau area is characterized by tree-covered steep mountainous islands, numerous ocean channels and an extensive shoreline containing small coves and bays. The area frequently has low ceilings and reduced visibility due to rain, fog and mist.
U.S. Coast Guard ships and aircraft, Alaska State Troopers and ground search volunteers participated in searches that lasted more than two weeks. No emergency locator signal was received by search personnel. Family members and volunteers continued to search for the missing airplane after the official search ended. Search personnel reported that survival time in water less than 40 degrees F is typically less than one hour.
On June 8, 2012, a Cessna 150F with only the pilot on board took off from an airport at Germansville, Pa., for a day/VFR personal flight. The following day, a family member reported the airplane and pilot were missing. According to a review of radar data, the airplane flew on an easterly heading that took it over the Atlantic Ocean. After 172 nautical miles, radar contact was lost. A search was conducted by the Civil Air Patrol and the U.S. Coast Guard. After four days, the search was called off. The airplane wasn't located, and no debris was sighted.
It took 51 days to find out what happened to a Cessna 172N that went missing on June 21, 1997, even though the airplane had been squawking a discrete transponder code at takeoff. The rented airplane carried a commercial pilot who was fatally injured. It had departed Santa Barbara, Calif., on a day/VFR personal flight. It struck mountainous terrain just over 12 miles south of Cuyama, Calif. The rental facility became concerned when the airplane failed to return at the scheduled time, and a search was initiated. No evidence of emergency locator beacon transmissions was recorded in the mountains surrounding the Santa Barbara area. The accident site was located on August 10, 1997.
When recorded radar data from the Los Angeles Air Route Traffic Control Center was initially reviewed for the search, the airplane's discrete transponder code was seen departing Santa Barbara and flying in a northwesterly direction toward Santa Ynez. The radar track disappeared when the airplane was between 10 and 12 miles southwest of Santa Ynez. The accident site was about 21 miles north of the Santa Barbara Municipal Airport.
After the accident site was finally located, radar data was reexamined to look for any returns that might have been missed during the initial review. In addition to the discrete transponder code that had been used by the accident airplane, investigators looked for VFR codes of 1200 and primary returns without transponder enhancement. No evidence of radar tracks in the vicinity of the crash site was found.
On May 28, 1999, a Cessna 152 failed to return to Felts Field at Spokane, Wash., from a dual instructional flight. The airplane remained missing for just over two years until July 24, 2001, when the aircraft's wreckage was discovered by a U.S. Forest Service employee who had been performing routine duties in the Idaho Panhandle National Forest about 15 miles northeast of Coeur d'Alene, Idaho. Both the instructor and student had been killed, and the aircraft was destroyed. Visual meteorological conditions had existed for the flight, and the aircraft wasn't on a flight plan. Searchers hadn't detected an ELT signal. Radar showed a 1200 transponder code departing Felts Field and heading generally eastbound toward the accident site. The last recorded position for this track was about 12 miles northeast of Coeur d'Alene.
Initial search and rescue operations were coordinated by the Air Force Rescue Coordination Center at Langley Air Force Base, Va. These involved the Washington State Aviation Division, the Civil Air Patrol, Idaho Transportation Department Aeronautics Division, a U.S. Air Force helicopter, a commercial aerial ambulance helicopter and the Kootenai County, Idaho, Sheriff's Office. AFRCC suspended the search on June 8, 1999. The area where the Forest Service employee ultimately found the wreckage had been covered in the initial search.
A Piper PA-46-350P Malibu was lost from radio and radar contact on April 11, 1998. It was about 20 nm east-southeast of Glacier Park International Airport, Kalispell, Mont., at the time. It was on an IFR flight plan from Bismarck, N.D., to Kalispell and had been cleared to descend for its approach. It took just over two months to find the wreckage, which was approximately 10 nm east-northeast of Bigfork, Mont. The aircraft was destroyed, and the pilot and passenger had been killed.
Following the last FAA radar contact with the aircraft, a military radar site near Malmstrom Air Force Base (AFB), Great Falls, Mont., recorded a series of 11 primary radar returns in the accident area.
The search was coordinated by the Montana Aeronautics Division and involved air and ground searchers from the state, the U.S. Air Force, the Civil Air Patrol, the Flathead County Sheriff's Office and private parties. Poor weather, including snow, hampered initial search efforts. The full-scale search for the aircraft was called off after 11 days. Families of the pilot and passenger arranged for a private search. A search pilot they had hired found the accident site about two months later.
It took more than a year for evidence to be found following the disappearance of a Bellanca Super Decathlon carrying wealthy businessman and adventurer Steve Fossett despite massive official and private search efforts. Fossett held 116 records in various sports, maritime and aviation areas, including being the first person to fly solo nonstop around the world in a balloon. The day/VFR flight in the Bellanca originated from a private airport at the Flying M Ranch near Yerington, Nev.
The Civil Air Patrol, state and county authorities, and friends of the pilot initiated an extensive search for the missing airplane. The search area stretched over two states. The official Civil Air Patrol search was suspended after a month.
A year later, a hiker notified a sheriff's department that he had found personal effects, including a pilot certificate belonging to Fossett, in the Sierra Nevada Mountains. A new search found the airplane's wreckage about a half mile from where the personal effects had been found. An aircraft had flown over the crash site during the initial search, but the wreckage wasn't observed at that time. The crash site was about 65 miles south of the departure airstrip.
Peter Katz is editor and publisher of NTSB Reporter, an independent monthly update on aircraft accident investigations and other news concerning the National Transportation Safety Board. To subscribe, write to: NTSB Reporter, Subscription Dept., P.O. Box 831, White Plains, NY 10602-0831.