Adds comments from hearing, background after paragraph 3

By David Shepardson

WASHINGTON, Dec 12 (Reuters) - The incoming chair of the U.S. Senate Commerce Committee said on Thursday that the Federal Aviation Administration must take actions to modernize air traffic control systems.

Senator Ted Cruz said at a hearing on air traffic issues that he plans to "focus heavily" on the status of U.S. airspace when he takes over next year.

"The status quo of how the FAA modernizes our ATC is unacceptable," Cruz said. "We are stuck with technology that is outdated almost as soon as it is introduced into the airspace."

Cruz said he plans to look at "the status of the airspace and what changes may be necessary to enhance its efficiency and reliability."

A computer outage to a key pilot alerting system in January 2023 disrupted 11,000 flights and forced a halt to all U.S. passenger airlines' departing traffic for almost two hours, the first such action since the Sept. 11, 2001, attacks.

The Government Accountability Office in September said the FAA must take "urgent action" to address aging air traffic control systems.

GAO said the FAA determined that 51 of its 138 systems are unsustainable, citing 17 of those "unsustainable systems" as especially concerning and another 54 were potentially unsustainable. However, the FAA does not plan to complete modernization projects for many systems for at least a decade.

A union representing air traffic controllers said on Thursday that many facilities "are plagued by leaking roofs, flooding basements that contain electronic systems, broken-down elevators and HVAC systems, and chronically backed-up bathroom toilets."

The White House in March proposed spending $8 billion over the next five years - beginning with $1 billion in 2025 - to replace or modernize more than 20 aging air traffic control facilities and 377 critical radar systems.

The FAA is also suffering from a persistent shortage of air traffic controllers - and remains about 3,000 controllers behind staffing targets - and a series of near-miss incidents have raised serious safety questions. At several facilities, controllers work mandatory overtime and six-day work weeks to cover shortages.

The FAA said in June that it was extending cuts to minimum flight requirements at congested New York City-area airports through October 2025, saying the number of controllers handling traffic in New York is insufficient for normal traffic levels.

(Reporting by David Shepardson; Editing by Mark Porter)

((David.Shepardson@thomsonreuters.com; 2028988324;))