FAA orders inspections of all 737s; airlines expect no operational disruption

The FAA this week issued a directive to all airlines operating the Boeing 737, mandating new inspections on a switch that controls cabin pressure. The good news: summer travelers shouldn't see any impact.

The airworthiness directive (AD) applies to all 737 aircraft of every generation, from the original models through the latest 737 MAX. There are 2,502 of the aircraft active in the U.S., and 9,315 globally.

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There are two cabin altitude pressure switches on each 737. If they fail at the same time, cabin pressure could drop, leading to dangerously low oxygen levels.

Importantly, this has not happened during an actual flight. The order was prompted after several reports of newly installed pressure switches failing during testing.

Normally, the switches are tested every 6,000 flight hours. Under the new rule, those tests will be mandated every 2,000 flight hours, instead. All active aircraft must be checked within 2,000 flight hours of their last test, or within 90 days of the AD taking effect — the rule is scheduled to be published on Tuesday, July 20.

According to the FAA, each inspection and — if necessary — replacement, should take no more than an hour.

U.S. airlines that rely on various 737 models, including American Airlines, Southwest Airlines, United Airlines, and Delta Air Lines, told TPG that they do not expect any operational impact due to the required inspections, which can be accomplished during standard maintenance or other time spent on the ground.

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Representatives for Alaska Airlines did not immediately return a request for comment.