Air carrier flight crew reported a pressurization malfunction during the initial descent. The crew started an immediate descent to a safer altitude; then continued to a landing at the destination.
Synopsis
Air carrier flight crew reported a pressurization malfunction during the initial descent. The crew started an immediate descent to a safer altitude; then continued to a landing at the destination.
Narrative
During descent into ZZZZ from FL410 down to FL290 warning horn then cabin altitude light came on passing through around FL350. Memory items immediately accomplished successfully (oxygen masks and crew communications established). Myself (PF) continued flying while PM (captain) announced to ATC and cabin that descent was needed. PM continued immediate checklist items which led to dropping passenger oxygen masks with cabin altitude not controllable. PM ran QRH remaining items; we passed through 10;000ft with further coordination for lower altitude. Shortly after we coordinated that I will attempt to take my mask off evaluate; then Captain will take his mask off; the cabin altitude was verified below 10;000 feet on the gauge. We finished all checklists; notified dispatch of the descent and landing at destination. We were vectored for RNAV RWY XX into ZZZZ; all non-normal and deferred checklists were complete and a normal landing and taxi followed. No medical intervention required.As mentioned above: company SOP; memory items; immediate checklists ; QRH; non normal checklists followed. Descent deemed necessary.
Second reporter narrative
During Descent into ZZZZ passing approx FL350 to cleared level 290; the cabin altitude warning horn came on with the cabin altitude light. We accomplished the cabin altitude memory items; The cabin was uncontrollable; the passenger oxygen masks were deployed and cabin was informed of an emergency descent and initiated. We [notified] ATC. We requested to descent to 10000ft and was cleared the same. The checklist was referred and descent NNC (non-normal checklist) completed. We notified dispatch and landed at destination. There was no medical concern onboard the aircraft; ATC was informed of the same with POB (Portable Oxygen Bottle) AND NO DANGEROUS GOOD ON BOARD. [Request priority handling] with ATC; Descent initiated to safe altitude (10000ft)passenger oxygen masks deployed; memory items/checklist and NNC completed.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.