Crew and passengers would be fine up to around 14,000 feet MSL. Above that, expect a little shortness of breath. Above 18,000 feet pressure altitude hypoxia starts setting in, depending on one’s aerobic condition.
And yes, the crew used poor judgement saying the words “going down.”
TC
Grab a mask, pull and attach to face.
Pilots in full control the entire time.
Would like to know more about this plane ...
Most sea level people find it hard to breathe at even 5,000 feet, I have seen that when I worked on a cruise boat at Lake Tahoe, and I have personally worked at 9200 feet as a snowcat mechanic. But Alaska Airlines handle that situation perfectly, I fly them a lot, they are the best.