W81592 - Incident: Cargojet B763 at Sao Paulo on Nov 10th 2021

A Cargojet Airways Boeing 767-300 freighter, registration C-GVIJ performing flight W8-1592 from Sao Paulo Viracopos,SP (Brazil) to Miami,FL (USA) with 2 crew, was climbing out of Viracopos Airport when the crew stopped the climb at FL260 when the crew noticed the cabin would not pressurize more than 5 psi and was unable to maintain pressure. Both pressure controllers were failed. The crew declared PAN PAN, descended to FL100 and returned to Viracopos for a safe overweight landing about 90 minutes after departure.

The Canadian TSB reported maintenance replaced the center RAD ALT Transceiver. The lower pressure relief valve was found open by foreign object debris (FOD), the FOD was removed and the valve closed. The cabin pressure controllers were replaced, the first officer's display control panel was replaced, the captain's FMC was tested and found servieable, an overweight inspection conducted and the aircraft was returned to service.

The aircraft was able to finally reach Miami on Nov 11th 2021.

The aircraft had suffered a similiar problem 3 days earlier, see Incident: Cargojet B763 at Sao Paulo on Nov 7th 2021, cabin altitude warning and was on its first flight following that occurrence.