Pan Am Flight 202
| Pan Am Flight 202 | |
|---|---|
.jpg) A Pan Am aircraft of the same construction |
|
| Accident summary | |
| Accident type | structural failure |
| place | northern Brazil , approx. 240 km northwest of Palmas |
| date | April 29, 1952 |
| Fatalities | 50 |
| Survivors | 0 |
| Aircraft | |
| Aircraft type | Boeing 377 |
| operator | Pan American World Airways |
| Mark | N1039V |
| Surname | Clipper Good Hope |
| Departure airport | Ezeiza Airport , Buenos Aires |
| 1. Stopover | Carrasco Airport , Montevideo |
| 2. Stopover | Galeão Airport , Rio de Janeiro |
| 3. Stopover |
Piarco Airport , Port of Spain (planned, not reached) |
| Destination airport | Idlewild Airport , New York |
| Passengers | 41 |
| crew | 9 |
| Lists of aviation accidents | |
On April 29, 1952, a Boeing 377 Stratocruiser broke on Pan-Am Flight 202 as a result of structural failure over the Brazilian state of Pará . All 50 occupants were killed in the crash. It was the worst accident for this type of aircraft.
Flight history
A scheduled flight from Buenos Aires to New York was operated with the Boeing 377 of Pan American World Airways . Scheduled stopovers were planned in Montevideo , Rio de Janeiro and Port of Spain .
The plane coming from Montevideo landed on April 28, 1952 at 10:05 p.m. local time (01:05 GMT ) at Galeão Airport in Rio de Janeiro, where refueling and crew replacement took place. At 11:17 p.m. (02:17 GMT), the aircraft took off for its onward flight to Port of Spain ( Trinidad and Tobago ) and rose to a cruising altitude of around 3,800 meters (12,500 feet ). The pilots were given permission to set a direct course to the destination airport and flew outside of airways according to visual flight rules . The planned flight time to Port of Spain was over 11 hours.
The crew reported regularly to Brazilian air traffic control when the abeam position of one of the radio beacons next to the route was reached. The aircraft remained at its original cruising altitude of 3,800 meters (12,500 feet) until 1:45 a.m. (4:45 GMT). At 03:45 a.m. (06:45 GMT) a station in Cayenne ( French Guiana ) received a routine report from the crew and forwarded it to the air traffic controllers in Belém . The Boeing 377 was at an altitude of around 4,400 meters (14,500 feet) at the time. The pilots stated that they were expected to reach a position west of the radio beacon in Carolina ( Maranhão , Brazil) at 04:45 am (07:45 GMT) . This was the last radio contact with the plane. The crash presumably occurred around 04:40 a.m. (07:40 GMT), approximately 1,640 kilometers north-northwest of Rio de Janeiro.
Scene of the accident
On May 1, 1952, search planes discovered a burnt-out area about 30 meters wide in the (then still) dense rainforest, which marked the scene of the accident. The region was far away from human settlements and traffic routes, around 60 kilometers west of the banks of the Rio Araguaia . In order to get to the crash site, a 40-kilometer path through the jungle had to be cut with considerable effort. On May 16, eight accident investigators reached the wreck, but they had to stop their investigations two days later due to lack of water. At the end of August 1952, another team of investigators pushed forward to the crash site. Three demarcated fields of debris were discovered, which indicated a breakup in flight. Starting from the main wreckage, the debris spread within a radius of approximately 1,200 meters (4,000 feet). The engine no. 2 (the inner left motor) and its propeller are not found in the search area and stayed gone.
Cause of accident
The Boeing 377 broke at cruising altitude, initially with engine no. 2 loosening. In quick succession, the outer part of the left wing and the rear fuselage section together with the vertical stabilizer and horizontal stabilizer broke off. The debris from these two assemblies was found around 700 meters and 1,200 meters away from the main wreck, respectively. As the machine crashed, other parts of the airframe tore off, including the ailerons and flaps of the right wing, as well as the cowling of engine number 4. The plane hit almost vertically and at high speed. Although the main wreck showed a high degree of destruction and was completely burned out, an explosion on board could be ruled out.
It was known from previous incidents that the hollow propeller blades of the Boeing 377 were prone to fatigue fractures even with minor external damage . The investigators assumed that the breakage of a propeller blade caused an imbalance in engine no. 2. The vibrations caused the engine to loosen and break off the left wing. Part of the engine cowling struck the left horizontal stabilizer and deformed its leading edge. The debris on the left side of the fuselage was covered with engine oil that came from the torn pipes. The pilots probably extended the landing flaps to keep the aircraft under control.
After the engine was torn down, most of its fairing remained on the wing. The changed flow profile resulted in turbulence which hit the left horizontal stabilizer and caused it to vibrate strongly (see buffeting ). The outer third of the fin broke from the overload. As a result of the break, the left elevator partially disengaged from its anchorage and fluttered in the airflow. The rudder probably deflected upwards in an uncontrolled manner, which abruptly increased the aircraft's angle of attack . The air flow then pressed against the underside of the damaged wing, so that its outer part bent upwards and broke away together with engine no. 1. When the aircraft tilted over its nose and went into a dive , the downward pressure on the top of the horizontal stabilizer increased suddenly . The load led to the entire rear section being torn down .
The commission of inquiry recommended that the hollow propeller blades used be replaced by a fully encapsulated type. However, this requirement was not implemented immediately, so that further Boeing 377s crashed for similar reasons in the 1950s.
Individual evidence
- ^ A b c d e f Civil Aeronautics Board, Accident Investigation Report, Pan American World Airways, INC., Near Carolina, Brazil, April 29, 1952
- ↑ The crash site was in an undeveloped, dense forest area that has now been almost completely cleared through clearing .
- ^ Aircraft disasters , David Gero, Stuttgart 1994
Coordinates: 9 ° 46 ′ S , 50 ° 47 ′ W