WASHINGTON (Reuters) - The chair of the National Transportation Safety Board will tell the Senate Commerce Committee on Wednesday the agency needs more funding and warn cuts could put probes into aviation and rail accidents at risk.

NTSB Chair Jennifer Homendy will tell a committee hearing, in written testimony seen by Reuters, that funding levels in a Senate bill "would require us to reduce staffing levels and would degrade our mission readiness for critical safety investigations".

Those probes include a February 2023 Norfolk Southern ( NSC ) train derailment in Ohio and another into the Jan. 5 mid-panel panel blowout of a new Alaska Airlines Boeing 737 MAX 9 aircraft.

"It is critical for the agency to have additional resources to respond to events," Homendy's testimony says. "We owe it to the families of those involved, to the communities where events occurred, and to the traveling public to find out what happened, why it happened, and to make recommendations to help ensure it never happens again."

Homendy says she expects President Joe Biden next week to request $150 million for NTSB for the 2025 budget year, up from $145 million proposed for this year.

A Senate bill would authorize $145 million for the NTSB next year, $5 million less than what Biden is expected to seek.

Homendy says the NTSB, with 230 investigators currently, needs 50 additional employees for full staffing including 16 aviation investigators and 10 highway investigators as well as another $2.4 million to replace aging and obsolete equipment "critical to conducting robust and comprehensive investigations."

Homendy's testimony noted the board has six open investigations from 2023 into runway incursion incidents and she has called for more technology to prevent near miss incidents.

In February 2023, a FedEx cargo plane and a Southwest Airlines Boeing 737 that came within about 115 feet (35 meters) of each other in Austin in poor visibility conditions could have been a "terrible tragedy," Homendy said last year.

The NTSB has over 1,000 open safety recommendations across all investigations, Homendy's testimony says.

"We meet the challenges that come with increasing growth and innovation in transportation," Homendy said. "It is critical for the agency to have additional resources to respond to events without affecting our timeliness, the quality of our work, or our independence."

(Reporting by David Shepardson; Editing by Lincoln Feast.)