* NTSB chair says fire truck that collided with Air

Canada Express jet lacked transponder

* NTSB said two controllers were working in tower's glass

enclosed section

* Runway status lights that warn it is unsafe to cross

were operating

* Air crashes are typically caused by multiple factors

(Recasts, adds more details from briefing and expert comment

throughout)

By David Shepardson and Allison Lampert

NEW YORK/MONTREAL March 24 (Reuters) - Tracking

technologies designed to prevent runway collisions did not work

at New York's LaGuardia airport when an Air Canada Express

jet struck a fire truck on Sunday night, killing the two

pilots, the National Transportation Safety Board said on

Tuesday.

NTSB Chair Jennifer Homendy said the airport's ground

surveillance system did not generate an alert warning of the

close proximity of vehicles to the runway.

In addition, the fire truck that collided with the jet

lacked a transponder that would have transmitted its location to

air traffic control, she said.

The NTSB is leading the investigation into the fatal

collision of the CRJ-900 jet operated by Air Canada's ( ACDVF ) regional

partner Jazz Aviation. The crash sent 39 of the 76 passengers

and crew to hospital with varying degrees of injuries, with six

still hospitalized, Air Canada ( ACDVF ) said on Tuesday evening.

The Federal Aviation Administration has encouraged airports

to equip fire trucks with transponders because it makes the

vehicles' movements easier to track at busy airports.

"Controllers should have all the information, the tools to do

their job," Homendy said. "You have to have information on

ground movements, whether that's aircraft or vehicles moving."

U.S. air safety experts have said communications between the

plane ⁠that was landing, the air traffic controller and the fire

truck would be key areas of the investigation.

Air crashes typically are caused by multiple factors, and

the investigation's goal is to improve aviation safety.

The NTSB can make safety recommendations to the FAA, which

manages U.S. air traffic control, but they are not binding.

Homendy flagged longstanding NTSB concerns that controller

staffing was limited for the busy airport, despite meeting FAA

norms for an overnight shift. There were two controllers working

in a glass-enclosed section of the airport's traffic control

tower at the time of the crash, just before midnight.

"In this situation, for the midnight shift, it is standard

operating procedure that they only have two on duty and those

two perform the duties of other controllers," she told reporters

at LaGuardia. "Certainly, I can tell you that our air traffic

control team has stated this is a concern for them for years."

But she said questions remained over how the tasks were

divided between the two controllers and why the one involved in

clearing the truck was not relieved from duty immediately after

the accident.

20 SECONDS FROM CLEARANCE TO CRASH

Citing data from the cockpit voice recorder, the NTSB said

there were only 20 seconds from the moment the truck was given

clearance to cross the runway to assist another plane and the

end of the recording. Nineteen seconds before the end, an

electronic callout told the pilots they were 100 feet above the

ground.

Former FAA Air Traffic Control Specialist Mike McCormick

said the Air Canada Express pilots would likely not have had

enough time to abort their landing. The truck crossed the runway

just nine seconds before the crash.

Homendy said the runway status lights that flash red and

warn it is unsafe to cross a runway were operational. That

raises questions about why the truck crossed, McCormick said.

The accident occurred on a misty evening, and Homendy said

visibility from the airplane and truck would be examined.

The NTSB, which has sounded the alarm about close calls and

runway incursions for years, last month found the deadly January

2025 mid-air collision of an American ​Airlines regional

jet and an Army helicopter occurred in part because the high

workload "degraded controller performance and situation

awareness".

Homendy said that the NTSB was interviewing on Tuesday the

local controller who started at 10:45 p.m. ET after a shift

change 15 minutes earlier and whose interactions with different

planes and the truck were heard on liveatc.net.

Air traffic controllers make decisions about when planes can

land and take off, and when ground vehicles can enter runways.

The controller who made the call for the Air Canada ( ACDVF ) flight ​to

land had been trying to find a gate for a separate United

Airlines flight that complained of a bad odor, according to the

recording.

The incident has raised concerns over whether the controller

was distracted by the United Airlines flight, which had declared

an emergency.

"I would caution pointing fingers at controllers and saying

distraction was involved," Homendy said. "This is a heavy

workload environment."