By David Shepardson
WASHINGTON (Reuters) - A senior U.S. lawmaker wants details from the Federal Aviation Administration (FAA) about the safety of the cockpit alerting system for the Boeing 737 MAX -- an issue at the heart of a dispute over two new variants of the best selling airplane.
Senate Commerce Committee Chair Maria Cantwell on Tuesday circulated a draft proposal that would extend the 737 MAX 7 and MAX 10 certification deadline and require retrofitting existing planes with safety enhancements, Reuters reported.
Cantwell told Reuters on Tuesday she had asked the FAA for additional information as she works to reach agreement on legislative language that would lift the deadline. "Safety should be the focus, not a date, safety," she said.
Boeing is seeking an extension from Congress of a Dec. 27 deadline imposing a new safety standard for modern cockpit alerts after two fatal 737 MAX crashes killed 346 people in Indonesia and Ethiopia and led to the plane's 20-month grounding.
A timely FAA response could help address concerns among some other lawmakers who oppose Boeing's request, potentially opening the way for an extension to be granted following months of discussions.
In a previously unreported Nov. 23 letter to the FAA seen by Reuters, Cantwell sought additional information on its certification of the Boeing 737 MAX fleet and compliance with the crew alerting requirements" by Dec. 5.
After Dec. 27, all planes must have modern cockpit alerting systems to be certified by the FAA, which could put the two new MAX planes future in jeopardy.
Cantwell's letter asked "to the extent FAA has identified safety deficiencies with 737 MAX's flight crew alerting system, please describe FAA's plans to immediately address these safety concerns."
The FAA said it "was working on a response" to Cantwell's letter.
Lawmakers are discussing whether to include the provision in the House version of an annual defense bill, sources told Reuters.
Relatives of those killed in the crashes vehemently oppose to waiving the alerting requirements.
"How many people have to die for Boeing to be required to follow the law and install safe, modern flight crew alerting in their aircraft?" Michael Stumo, whose daughter died in the Ethiopian Airlines MAX crash, asked on Wednesday.
Boeing declined to comment but has said it is safer to have one common cockpit alerting system for all versions of the 737.
Acting FAA Administrator Billy Nolen told reporters earlier this month he did not view either version of the MAX as better. "There is no safer," Nolen said. "It's safe or it's not. If it is not safe, it should not be flying."
(Reporting by David Shepardson; Editing by Sam Holmes)