The Federal Aviation Administration (FAA) has shut down Xtra Aerospace of Miramar, Fla., the company that supplied a faulty sensor to Lion Air that triggered the deadly 2018 crash of a 737 MAX, killing 189 people.

The regulator’s revocation of Xtra’s aviation repair station certificate, announced Friday, means Xtra is out of business.

Late Friday, Xtra issued a statement saying that “we respectfully disagree with the agency’s findings.” It added that the revocation of its certificate “is not an indication that Xtra was responsible for the accident.”

The news came the same day that the final investigation report into the Lion Air accident was released Friday by the National Transportation Safety Committee of Indonesia, known by its Indonesian acronym KNKT.

A Boeing 737 Max 8 sits behind the Boeing 737 Renton factory waiting for engines. The Angle of attack (AOA) instrument of the 737 MAX, is the bottom piece of equipment below just below the cockpit windshield. 

Photographed on March 13, 2019 209611 209611

In other responses to that report, Boeing said it is “addressing the KNKT’s safety recommendations,” and in Congress members of both House and Senate vowed to push through legislation to improve regulation of air safety.

Xtra repaired and approved for service a secondhand angle of attack sensor that was installed on the Lion Air jet to replace a faulty one. But according to the final KNKT investigation report, the replacement sensor was mis-calibrated so that the angle it registered was 21 degrees too high.


The FAA revocation order said Xtra “recklessly and systemically” failed to comply with federal safety requirements. The order was issued on the day that the KNKT report observed that the FAA’s oversight of Xtra before the crash had been inadequate.

Asked why the FAA had waited until the final investigation report was published to stop the Florida operation, a spokesman for the safety agency said “it typically takes several months to conduct a thorough investigation, review the findings and determine whether an operator or repair station complied with Federal Aviation Regulations.”

Secondhand part

The component that triggered the sequence that led to the Lion Air MAX crash had originally been installed on an older Boeing 737-900ER aircraft in Malaysia and was sent for repair a year earlier to Xtra, where the unit was disassembled and an eroded vane replaced.

Xtra calibrated and tested the component and approved it for return to service in November 2017. It was installed on the Lion Air jet on Oct. 28, the day before the fatal flight.

On Flight 610, the next day, the replacement sensor was off by 21 degrees from the one on the other side of the plane. After the pilot retracted the flaps, Boeing’s new flight control system — MCAS (Maneuvering Characteristics Augmentation System) — assumed the angle of attack was too high because of the input from that one bad sensor, and began to push the nose of the aircraft down, leading to the crash.

The KNKT report states that the sensor “was most likely improperly calibrated at Xtra Aerospace.” The company did not have a written procedure that specified the proper position of a switch on the test equipment that could have led to the mis-calibration.


The report notes that the FAA missed this, though it is responsible for overseeing quality control at aircraft component suppliers.

On Friday, the FAA said an investigation begun after the Lion Air accident “determined that from November 2009 until May 2019, Xtra failed to complete and retain records in accordance with procedures in its repair station manual.” It also itemized other failures and said Xtra “did not substantiate that it had adequate facilities, tools, test equipment, technical publications, and trained and qualified employees.”

Boeing and Congress respond

After the official release of the KNKT report, Boeing issued a statement commending the Indonesian safety committee for “its extensive efforts to determine the facts.”

The statement outlined the upgrade of MCAS that Boeing has completed to address the design flaws identified in the report.

“Going forward, MCAS will compare information from both AOA sensors before activating,” Boeing said. “In addition, MCAS will now only turn on if both AOA sensors agree, will only activate once in response to erroneous AOA, and will always be subject to a maximum limit that can be overridden with the control column.”

Finally, Boeing said it “is updating crew manuals and pilot training, designed to ensure every pilot has all of the information they need to fly the 737 MAX safely.”


In Congress, U.S. Senate Commerce Committee ranking member Maria Cantwell (D-WA) Thursday introduced legislation to implement recent National Transportation Safety Board (NTSB) recommendations related to how pilots respond to flight deck alerts and increased automation in aircraft cockpits.

Cantwell pledged to review the recommendations from the investigations into both 737 MAX tragedies and to “consider additional legislation to help maintain the industry’s strongest safety standards.”

And in the House, Peter DeFazio (D-OR), Chair of the House Committee on Transportation and Infrastructure, and Rick Larsen (D-WA), Chair of the Subcommittee on Aviation, issued statements on the Lion Air final report.

“I will be introducing legislation at the appropriate time to ensure that unairworthy commercial airliners no longer slip through our regulatory system,” said DeFazio.

“One thing is abundantly clear: the method by which the FAA certifies aircraft is itself in need of repair,” said Larsen.

Clarification: An earlier version of this story said Xtra Aerospace failed to do “an extra check” of the AOA sensor calibration. The report says the mis-calibration of the AOA sensor could have been caused by a switch in the wrong position on the test equipment at Xtra Aerospace — and that Xtra did not provide the required written instructions for how to correctly use the equipment.