The aircraft involved 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.

[3] 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.

[3]: 7–10 An unusual cold front was developing in the vicinity of Pucallpa, minutes before the event took place, with cloud tops estimated to be 45,000 feet (14,000 m) high.

The aircraft flew through a hailstorm for the last 32 seconds of its ill-fated flight when it was taken down by wind shear, hit tree tops and impacted a swamp located 3.8 nautical miles (7.0 km; 4.4 mi) ahead of the runway threshold.

[2] The captain took control of the plane, but the trainee 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 avoided danger.