CNN
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Investigators searching for wreckage from last week’s deadly midair collision between a US military Black Hawk helicopter and an American Airlines plane near Washington, DC, conducted an overnight scan of the Potomac River where the aircraft fell using advanced imaging technology to map the riverbed and locate debris.

The scan was performed by the National Oceanic and Atmospheric Administration between 2 a.m. and 5 a.m. on Saturday by using an aircraft to deploy green laser pulses to map the riverbed and locate debris from the collision. The technology, called TopoBathy lidar, is designed to produce detailed underwater imagery and guide recovery teams.

The scan was initially scheduled to take place overnight on Friday but was delayed until Saturday, weather permitting, the National Transportation Safety Board said. Information from Saturday’s scan will be part of the NTSB’s ongoing investigation, the agency told CNN.

The collision on January 29 killed 67 people near Ronald Reagan Washington National Airport. Among the pieces still missing are the Black Hawk’s right engine and tail rotor.

The NTSB, along with the Naval Sea Systems Command Supervisor of Salvage and Diving, lifted much of the Black Hawk and other large portions of wreckage from the river Thursday.

Investigators have begun examining the material and flight data from both aircraft to reconstruct the events leading to the crash.

Lawmakers were briefed Thursday by investigators examining the collision, but no significant new findings were disclosed, they said.

After the briefing, NTSB chair Jennifer Homendy said investigators were still determining whether the Black Hawk’s ADS-B system — an advanced surveillance technology that provides real-time tracking data — was installed and operational at the time of the crash.

“We believe there are avionics on that helicopter that we need to evaluate in order to determine what they did have and what was on at the time. More to come,” Homendy told reporters.

The ADS-B system transmits critical information, including an aircraft’s location, altitude, positioning and speed to other aircraft and air traffic controllers. Whether this system had a role in last week’s collision has become a focal point for lawmakers.

“This was a training mission, so there was no compelling national security reason for ADS-B to be turned off,” said Sen. Ted Cruz, the chairman of the Senate Commerce, Science and Transportation Committee, which has oversight of commercial airspace.

Sen. Tammy Duckworth, a former Black Hawk pilot in the Army, noted, “It’s not clear whether the technology was turned on, but the Army confirmed it was installed in the aircraft.”

The Black Hawk, stationed at Fort Belvoir in Virginia, was conducting an annual proficiency training exercise in “government continuity” at the time of the collision, according to Secretary of Defense Pete Hegseth. He noted the pilots were highly experienced and wearing night vision goggles during the flight.

FAA expands safety review amid broader concerns

While recovery teams continue their search, the Federal Aviation Administration has reduced air traffic at the airport, partly because of the recovery efforts but also due to weather conditions, an FAA spokesperson said in a statement Thursday.

The airport’s hourly arrival rate decreased from 28 to 26 flights, causing average delays to rise from 40 to 50 minutes, according to a source familiar with the situation.

Several senators, including Cruz, called for a review of airports nationwide that handle significant helicopter traffic in close proximity to commercial jets, something the FAA announced Thursday it will carry out.

CNN’s Emma Tucker, Andy Rose and Holly Yan contributed to this report.