The FAA has ordered safety checks on all 9,300 Boeing 737 aircraft

[Guest1]

The FAA has ordered safety checks on all 9,300 Boeing 737 aircraft for a failure that could cause cabin oxygen levels to drop dangerously low

gdean@insider.com (Grace Dean)  7 hrs ago

Airlines have been told to inspect 2 pressure switches on Boeing 737s over concerns they could fail.

Their failure could mean that cabin oxygen levels fall dangerously low, the FAA said.

An unnamed operator reported that the switches failed in tests on three different 737 models.

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The US aviation watchdog has instructed airlines to inspect a pair of pressure switches found on all Boeing 737 airplanes over concerns that their failure could cause onboard oxygen levels to fall dangerously low.

The Federal Aviation Administration (FAA) on Thursday warned of a risk that pilots and other crew members could lose consciousness if the cabin altitude switches failed. It issued a directive ordering that airlines check them for faults.

The directive applies to around 2,500 Boeing 737 planes in the US and a further 9,315 worldwide, Reuters reported. It includes the 737 Max.

"A latent failure of both pressure switches could result in the loss of cabin altitude warning, which could delay flight crew recognition of a lack of cabin pressurization, and result in incapacitation of the flight crew due to hypoxia (a lack of oxygen in the body), and consequent loss of control of the airplane," the agency said.

It added: "Addressing these failures requires immediate action."

The FAA didn't say there had been any in-flight failures of the switches. However, it said that in September, an unnamed airplane operator reported that both switches had failed on three different 737 models it tested.AA's direction," the airline told The New York Times.

story link: The FAA has ordered safety checks on all 9,300 Boeing 737 aircraft for a failure that could cause cabin oxygen levels to drop dangerously low (msn.com)

[Don Hudson]

Hmm, somebody at the NYTimes doesn't understand the science of partial pressure of gasses like oxygen (PO₂), how O₂  gets into the blood stream, nor do they appear to know the composition of the air we need to breath every few seconds or so!

I think that the NYTimes has done a really poor job of writing this story. Initially I thought it had to do with the aircraft emergency oxygen system, "failing" to provide oxygen in a depressurization and wondered where "switches" came into play! I read further, and more slowly. There are no "oxygen switches" and one can't "increase oxygen" by turning the cabin airflow on "High".

Oxygen levels don't "drop" because of failed switches on airplanes of course! What drops is the partial pressure of all gasses. So if there is a loss of pressurization, there is less partial pressure for nitrogen, oxygen, argon, carbon-dioxide, etc., to cross the membranes in the lungs, and hopefully the cabin pressure sensors that warn the crew of a cabin altitude higher than approximately 10,000ft, work.

I'm sure those in charge will get it right and find/fix the problem, then have a chuckle at the NYTimes' level of "aviation" knowledge and consquently its writing.

 

[Airband]

3 hours ago, Don Hudson said:

I think that the NYTimes has done a really poor job of writing this story.

With respect, the New York Times did not write or publish the report referred to above.

[Don Hudson]

Thanks Airband. I know the link above doesn't lead to the NYTimes. The NYTimes story is linked in the "Business Insider" story, (the link above).

The article that I mention was written regurgitated by Niraj Chokshi of the NYTimes on July 15, 2021, (same as the other two), and published by the Times:  https://www.nytimes.com/2021/07/15/business/boeing-737-inspection.html and misleading info was just passed on.

It appears that REUTERS initially published the story, referencing "oxygen levels".

My original comments are still relevant and stand but with the world burning & seeming to come apart that the seams, it's not important so long as the issue is fixed by experts and not the internet. 

Edited July 21, 2021 by Don Hudson

[Airband]

Understood, thx.