WASHINGTON (Reuters) – The union representing 15,000 American Airlines pilots said on Wednesday it opposes an effort in Congress to extend an exemption from modern cockpit alerting requirements for the 737 MAX 7 and 10.

Boeing faces a December deadline to win approval from the Federal Aviation Administration (FAA) of the 737 MAX 7 and 10 variants, or it must meet new modern cockpit-alerting requirements that could significantly delay the plane’s entry into service.

The Allied Pilots Association said “Boeing needs to proceed with installing modern crew alerting systems on these aircraft to mitigate pilot startle-effect and confusion during complex, compound system malfunctions.”

(Reporting by David Shepardson; Editing by Chris Reese)