The airtraffic control tower stands at LaGuardia Airport (LGA) in theQueens borough of New York, U.S., on Friday, Jan. 25, 2019. TheFederal Aviation Administration temporarily halted flights into NewYork's LaGuardia Airport because of a shortage of air-trafficcontrol staff, escalating the pressure on President Donald Trumpand lawmakers to end the government shutdown.Photographer: Mark Kauzlarich/Bloomberg

The aviation system's safety still hasn't fullyrecovered from the 35-day U.S. government shutdown that haltedprogress on new technology and stopped reviews of incident reports,the air-traffic controllers' union president told Congress.

U.S. aviation was “on the verge of unraveling” when the partialshutdown ended Jan. 25. Flights were delayed into New York'sLaGuardia Airport as controllers didn't report to work due toillness and fatigue, said Paul Rinaldi, president of the National Air TrafficControllers Association.

The shutdown cut off funding to more than a dozen departmentsand agencies and was the result of a political dispute betweenPresident Donald Trump and lawmakers over funding for a wall on theMexico border. To prevent another shutdown, lawmakers must pass acompromise measure to renew long-term funding by Friday.

Wednesday's hearing before the House aviation subcommitteedelved into the impact of the shutdown on air safety in theU.S.

Installation of a new radar system designed to warn controllerswhen aircraft aren't lined up to land on the proper runway was oneof the programs that was temporarily halted, Rinaldi told the Houseaviation subcommittee on Wednesday.

FAA furloughed more than 1/3 of its workers

The new system is working at some airports, but its installationat others was halted when the Federal Aviation Administration (FAA)furloughed more than one-third of its workers as part of a partialgovernment shutdown that lasted 35 days.

The importance of the radar was highlighted in recent days whenthe system alerted controllers in Philadelphia that a plane washeaded for a taxiway instead of the runway, he said. A controllerordered the plane to halt its landing and it flew about 600 feetover two planes on the ground, Rinaldi said.

Nicholas Calio, president of the trade group Airlines for America,said safety during the shutdown wasn't compromised. However, someof the many layers of protection were temporarily jeopardized andit forced the FAA to delay some flights as a way to ensure safety,Calio said.

Shutdown reduced oversight

While no airline crew or aviation inspector knowingly allowed aplane to take off in an unsafe situation, the shutdown reducedoversight and could have led to inadvertent errors, said MikePerrone, president of Professional Aviation Safety Specialists.Perrone's union represents FAA safety inspectors and technicianswho maintain air traffic equipment.

“We don't know what we don't know,” Perrone said.

In addition to potential safety issues, the shutdown slowed orhalted scores of normally routine actions in the aviation industry,from hiring new airline pilots to approving new aircraft designs,said Calio and Pete Bunce, president of the General Aviation ManufacturersAssociation trade group.

Related: Safety board finally heads to deadly crash sitesfollowing government shutdown

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