Emergency decent to 10,000 feet

[earl1937]

  One the things which was a mystery to me about the emergency landing yesterday in Buffalo by an airliner, I think it was a Boeing 767, but not sure.
I would think that the emergency oxygen masks drop down for passenger use, is triggered by a low pressure switch somewhere in the cabin area, but the masks never dropped down in this instance's, why?
Not sure what the PSI should be in the aircraft at 38,000 feet, but would guess no lower than 5.5 PSI. Anyone have the correct info on the PSI standards prior to deployment of the masks?

[MrRiplEy[H]]

One the things which was a mystery to me about the emergency landing yesterday in Buffalo by an airliner, I think it was a Boeing 767, but not sure.
I would think that the emergency oxygen masks drop down for passenger use, is triggered by a low pressure switch somewhere in the cabin area, but the masks never dropped down in this instance's, why?
Not sure what the PSI should be in the aircraft at 38,000 feet, but would guess no lower than 5.5 PSI. Anyone have the correct info on the PSI standards prior to deployment of the masks?

IIRC the crew can stop the masks from dropping in cases where there's fire onboard for example. Maybe they blocked them?

[Mickey1992]

Could the issue have been toxic fumes or something similar?

“After examination by maintenance personnel and local authorities, there have been no indications of a pressurization problem or other issues with the aircraft,” Marissa Snow, a spokeswoman for SkyWest Airlines, said in a statement. “Our investigation is ongoing.”

http://www.washingtonpost.com/news/post-nation/wp/2015/04/22/plane-makes-emergency-landing-in-buffalo-after-passenger-passes-out/

[Toad]

It was an Embraer E175.  About 7 minutes to come down from 37k to 10k. Highest rate of descent about 7k/min.

http://flightaware.com/live/flight/SKW5622/history/20150422/1420Z/KORD/KBUF/tracklog

[PR3D4TOR]

It was an Embraer 175.

"...the pilot announced the plane was going to begin an emergency landing over Detroit. 'They said there was a pressure problem with the plane,' he said. 'There was no door flying open or anything like that. It was something very gradual.' "

If it was a gradual loss of pressure it may not have dropped low enough for the masks to pop. Only a couple of people fainted and they were perhaps more vulnerable due to other medical conditions.