Created Friday, Mar 19th 2021 21:15Z, last updated Friday, Mar 19th 2021 21:15Z
A Morningstar Air Express Avions de Transport Regional ATR-72-200 freighter, registration C-FTMN performing freight flight MAL-8066 from Saskatoon,SK to Calgary,AB (Canada) with 2 crew, was enroute at FL220 about 45nm westsouthwest of Saskatoon when the crew received a master caution and a "EXCESS CAB ALT" indication and noticed the cabin altitude was at 10,000 feet climbing at about 300 fpm. The crew checked the pressurization systems, which showed no abnormal indications. The crew initiated an emergency descent to 10,000 feet, and continued the flight at 10,000 feet to Calgary.
The Canadian TSB reported maintenance found during a walk around, that the document door was latched but not fully closed as insulation was protruding. The door was closed and latched properly. An operational test of the pressurization system as well as a leak test of the pressurization system were performed with satisfactory results.
