Following the grounding of Boeing's 737 MAX 9 following the serious incident on Alaska Airlines Flight 1282, opposition is growing to Boeing's request for a safety exemption needed to certify the next smaller model in the same jet family, the 737 MAX 7.
As political pressure mounted on the Federal Aviation Administration amid another tense and emotional debate over Boeing's compliance with safety standards, prominent U.S. Senators Tammy Duckworth, D-Illinois, and Maria Cantwell, D-Washington, spoke out Thursday granting the exception.
The timing of this aircraft's entry into service is now seriously questionable, as is that of its successor aircraft, the MAX 10.
In December, Boeing asked the FAA to exempt the MAX 7's engine anti-ice system from certain safety standards it doesn't meet.
The FAA admits that this system on the MAX has a potentially catastrophic flaw, although Boeing argues that such a fatal flaw is “extremely unlikely” and that a warning to pilots to turn off the system under certain circumstances is enough to stop it to make sure.
The MAXs currently flying are based on this assumption. For the MAX 7, which has yet to be certified, Boeing requested an exemption until June 2026 to have time to find a permanent design fix for the system.
On Thursday, Duckworth – a pilot and chairman of the aviation safety subcommittee of the Senate Committee on Commerce, Science and Transportation – called on the FAA to reject Boeing's request.
“The FAA should deny Boeing’s request for a waiver and urge the company to expedite the implementation of a mechanical repair of its faulty anti-ice system,” Duckworth wrote in a letter to new FAA Administrator Mike Whitaker.
More about Alaska Airlines and the Boeing 737 MAX 9
In a later statement, Cantwell, chairman of the Commerce, Science and Transportation Committee, supported Duckworth's position.
“The FAA has determined that this design feature is unsafe,” Cantwell said via email. “Now is not the time to talk about exceptions.”
Without the exemption, the MAX 7 cannot be approved for passenger flights. The plane was previously expected to receive FAA certification as early as this month and enter service with Southwest Airlines in the spring.
But on Thursday Southwest, by far the largest MAX 7 customer with 302 orders, said it had pulled the MAX 7 from its 2024 plans.
“Uncertainty remains regarding the timing of expected Boeing deliveries and certification of the MAX 7 aircraft,” Southwest Chief Financial Officer Tammy Romo said in a conference call with analysts to discuss 2023 results. “Our capacity plans for 2024 do not currently include a MAX 7 flight.”
A potentially catastrophic mistake
After Boeing reported the engine anti-ice system defect to the FAA, the 737 MAX 8 and MAX 9 models that carried passengers in the United States had to restrict use of the system since August.
The error could cause the inlet at the front end of the nacelle surrounding the engine – called the nacelle – to overheat and possibly break.
In an August airworthiness directive, the FAA noted that debris from such a breakup could enter the fuselage, endanger passengers seated at the windows behind the wings, and damage the wing or tail of the aircraft, “resulting in loss.” could lead to the control of the aircraft.”
To avoid this dangerous overheating, FAA guidance instructed pilots not to fly through dry air for more than five minutes after emerging from icy air with the engine anti-ice system on before turning it off.
That's the current protocol, and Boeing argues it should be OK to fly the MAX 7 with the same restriction.
“The 737 MAX has been in service since 2017 and has accumulated over 6.5 million flight hours. “During this period, there were no reported cases of parts leaking from the aircraft due to overheating of the engine nacelle inlet structure,” Boeing said in the filing.
Technically, the FAA can't approve a jet to carry passengers if it doesn't meet all safety standards, but it can grant an exemption from certain rules.
Still, critics balk at the idea of granting an exception for a potentially catastrophic error.
Before the recent MAX 9 incident, the Allied Pilots Association, the union that represents 15,000 American Airlines pilots, expressed serious concerns.
APA spokesman Dennis Tajer said it is not enough if there is no alarm on the instrument panel telling pilots that the system should be shut down.
After the Alaska Airlines MAX 9 incident this month in which a door-sized panel flew out of the fuselage at 16,000 feet over Portland — which Duckworth said “could have been catastrophic” — granting the exemption has become a hot political issue .
In her letter to the FAA, Duckworth referred to both the two MAX-8 crashes that killed 346 people five years ago and the incident in Alaska this month.
“Simply put, the FAA has certified two MAX variants to date – and both variants were ultimately discontinued,” Duckworth told Whitaker. “Boeing and FAA are 0-2 in developing and certifying 737 MAX variants without potentially fatal safety defects.”
She called on Whitaker to improve the FAA's “inconsistent record” of enforcing safety standards and to hold Boeing accountable.
The impact of the Alaska Airlines incident was far-reaching for Boeing.
Southwest's decision to remove the MAX 7 from its plans appears to be merely an acknowledgment of the fact that the airline cannot be certain of getting them this year.
Likewise, United Airlines CEO Scott Kirby said Tuesday that the airline is removing the MAX 10 from its fleet planning. This model, the largest variant of the MAX, should follow the MAX 7 next year.
“We are not canceling the order,” Kirby said on CNBC. “We are taking it out of our internal plans and will work with Boeing on exactly what that means.”
That could mean that United switches the order to smaller MAXs. Or it could order the Airbus A321 instead.
By grounding the MAX 9, the FAA has told Boeing that it cannot increase MAX production until quality management is under control.
Former Boeing executive and whistleblower Ed Pierson, who founded a lobbying group called the Foundation for Aviation Safety after the two deadly MAX crashes, filed a formal objection to Boeing's exemption request in December.
This week, Pierson sent a new letter to the FAA renewing the objection and noting that the foundation's review of the federal database that logs reports of in-flight incidents found multiple engine anti-ice valve failures I discovered that regulates the heated airflow of the system.
His letter cited two such failures on United MAXs this month that resulted in unscheduled landings. Another report dated Jan. 16 describes “a blister-shaped defect and cracks on the exterior of the No. 1 engine intake hood of a Southwest MAX.”
Boeing said in December that “inspections are ongoing” to determine whether the nacelles of the MAX planes in service are damaged.
APA's Tajer said in an interview Thursday that the pilots' union is asking American Airlines what the protocol is when an engine anti-ice valve sticks open, leaving the system on and the pilot unable to turn it off.
The current checklist for this scenario does not require the pilot to land at the nearest airport, and yet this appears to contradict the instruction not to fly in dry air for more than five minutes with the system on.
The APA wants clarity on this.
Meanwhile, Boeing's prospects are becoming increasingly uncertain.
Dominic Gates: [email protected]; Dominic Gates is a Pulitzer Prize-winning aerospace journalist for The Seattle Times.