A revised version of the House’s aviation safety bill now has the backing of the NTSB, but most of the families of the 67 victims of last year’s midair collision near Washington, D.C., still want to see tougher requirements to ensure the reforms are completed.

The National Transportation Safety Board said the Alert Act now addresses its recommendation to require all aircraft flying around busy airports to have key locator systems that would allow the pilots to know more precisely where the traffic around them is flying. The NTSB has been recommending the systems since 2008.

The victims’ families said Thursday that they are encouraged by the changes in the bill but won’t endorse it until it also has strict timelines for implementation, like the Senate bill that came up one vote short had.

“Any safety requirement that routes implementation through negotiated processes, administrative discretion, or multi-step rulemaking creates opportunities for delay that cost lives,” the families said. “The strongest version of this bill will set clear statutory timelines and performance standards that leave no room for process to become an obstacle.”

Two key House committees unanimously advanced the new version of the bill Thursday, so it will now go to the full House for a vote. Then representatives and senators will have to work together to tweak the bill before the Senate votes on it.

Senators Ted Cruz and Maria Cantwell, who crafted the Senate bill, also echoed the families’ concern that the Alert act still doesn’t include an ironclad requirement for the locator system that the NTSB said would have prevented the D.C. crash to be effective.

The Texas Republican and Washington Democrat said in a joint statement that any legislation will need the strongest standard for those systems to pass the Senate.

NTSB Chairwoman Jennifer Homendy sharply criticized the original version of the bill last month as a “watered down” measure that wouldn’t do enough to prevent future tragedies. But the board said in a statement that the revised version, which was drafted with input from experts at the agency that investigates crashes, would address the shortcomings their investigation identified.

The NTSB said this week that the bill would now require the Federal Aviation Administration, Transportation Department and the military to take actions that would address their recommendations.

The bill will now require planes to have Automatic Dependent Surveillance-Broadcast In systems that can receive data about the locations of other aircraft that would have alerted the pilots of an American Airlines jet sooner about the impending collision with an Army Black Hawk helicopter on Jan. 29, 2025. Most planes already have the ADS-B Out systems that broadcast their locations.

The NTSB cited systemic weaknesses and years of ignored warnings as the main causes of the crash, but Homendy has said that if both the plane and the Black Hawk had been equipped with ADS-B In and the systems had been turned on, the collision would have been prevented. The Army’s policy at the time of the crash mandated that its helicopters fly without that system on to conceal their locations, although the helicopter involved in this crash was on a training flight, not a sensitive mission.

A number of key industry groups, including the Airlines for America trade group and the National Air Traffic Controllers Association, have backed the House bill.