Aircraft

The aircraft involved in the accident was a 1981-built Boeing 737-244 Advanced, registered OB-1809, which had been leased to TANS Perú from the South African lessor company Safair two months prior to the accident occurrence. With manufacturer's serial number 22580 and powered with two Pratt & Whitney JT8D-17A engines, the airframe had its maiden flight on 4 August 1981, and was originally delivered to South African Airways. At the time of the accident the aircraft had accumulated 49,865 flight hours and 45,262 cycles, and was 24 years old.

Description of the accident

There was an unusual developing cold front in the vicinities of Pucallpa minutes before the event took place, with cloud tops estimated to be 45,000 feet (14,000 m) high. Instead of heading the aircraft to another airport, the pilots initiated the approach to Pucallpa Airport with torrential rains and strong winds in the background. Some ten minutes before the scheduled time for landing the plane started rocking. Realizing that the airport could not be safely reached amid that worsening weather conditions, the pilots attempted an emergency landing. The aircraft was flying through a hailstorm for the last 32 seconds of its ill-fated flight when it was seemingly taken down by a wind shear, hit tree tops, impacted terrain in a swamp located 3.8 nautical miles (7.0 km; 4.4 mi) ahead of the runway threshold, broke up as it crash landed and burst into flames, leaving a path 100 feet (30 m) wide and 0.8 nautical miles (1.5 km; 0.92 mi) long. The wreckage of the airplane was engulfed by the fire.

There were 91 passengers and seven crew members on board; 40 of them —35 passengers and five crew— lost their lives in the accident. Non-Peruvian occupants of the aircraft included 11 Americans, one Australian, one Colombian, and one Spaniard; Italians were also aboard, but the actual figures for them depend upon the source. Most of the fatalities were recorded for passengers travelling in the front of the aircraft. Fifty-eight people survived the accident, many of them suffering serious injuries, mostly burns and broken limbs.

Investigation

Investigation of the crash site was hindered by looters, who descended upon the crash and stole various elements to be sold for scrap. A US$500 (equivalent to $605.81 in 2015) reward did succeed in securing the return of the flight data recorder. After 312 days of investigations, there were no reports of any technical malfunction. The official cause of the accident was determined to be pilot error for not following standard procedures under adverse weather conditions. The pilot took control of the plane, but the co-pilot did not immediately monitor the instruments; as a result, the crew did not notice the rapid descent in the few crucial seconds they had where they could have accelerated out of danger. According to Aviation Safety Network, the accident ranks among the deadliest ones that took place in 2005. It was also the second major crash involving a TANS Perú airplane in slightly over two years.

In the media

Flight 204 has been the subject of a Reader's Digest story and an MSNBC documentary. The Canadian TV series, Mayday, has also produced an episode about the accident named ″Lack of Vision″.