Investigators will detail the causes of the midair collision over Washington and recommend changes

So many things went wrong last Jan. 29 to contribute to the deadliest plane crash on American soil since 2001 that the National Transportation Safety Board isn't likely to identify a single cause of the collision between an airliner and an Army helicopter near Washington that killed 67 people at its hearing Tuesday.

Instead, their investigators will detail what they found that played a role in the crash, and the board will recommend changes to help prevent a similar tragedy. Last week, the Federal Aviation Administration already took the temporary restrictions it imposed after the crash and made them permanent to ensure planes and helicopters won't share the same airspace again around Reagan National Airport.

Family members of victims hope those suggestions won't be ignored the same way many past NTSB recommendations have been. Tim Lilley, whose son Sam was the first officer on the American Airlines plane, said he hopes officials in Congress and the administration will make changes now instead of waiting until for another disaster.

''Instead of writing aviation regulation in blood, let's start writing it in data,'' said Lilley, who is a pilot himself and earlier in his career flew Black Hawk helicopters in the Washington area. ''Because all the data was there to show this accident was going to happen. This accident was completely preventable."

Over the past year, the NTSB has already highlighted a number of the factors that contributed to the crash including a poorly designed helicopter route past Reagan Airport, the fact that the Black Hawk was flying 78 feet (23.7 meters) higher than it should have been, the warnings that the FAA ignored in the years beforehand and the Army's move to turn off a key system that would have broadcast the helicopter's location more clearly.

The D.C. plane crash was the first in a number of high-profile crashes and close calls throughout 2025 that alarmed the public, but the total number of crashes last year was actually the lowest since the COVID-19 pandemic hit in 2020 with 1,405 crashes nationwide.

Experts say flying remains the safest way to travel because of all the overlapping layers of precautions built into the system, but too many of those safety measures failed at the same time last Jan. 29.

The helicopter route didn't ensure enough separation

The route along the Potomac River the Black Hawk was following that night allowed for helicopters and planes to come within 75 feet (23 meters) of each other when a plane was landing on the airport's secondary runway that typically handles less than 5% of the flights landing at Reagan. And that distance was only ensured when the helicopter stuck to flying along the bank of the river, but the official route didn't require that.

Normally, air traffic controllers work to keep aircraft at least 500 feet (152 meters) apart to keep them safe, so the scant separation on Route 4 posed what NTSB Chairwoman Jennifer Homendy called ''an intolerable risk to flight safety.''

The controllers at Reagan also had been in the habit of asking pilots to watch out for other aircraft themselves and maintain visual separation as they tried to squeeze in more planes to land on what the Metropolitan Washington Airport Authority has called the busiest runway in the country. The FAA halted that practice after the crash.

That night a controller twice asked the helicopter pilots whether they had the jet in sight, and the pilots said they did and asked for visual separation approval so they could use their own eyes to maintain distance. But at the investigative hearings last summer, board members questioned how well the crew could spot the plane while wearing night vision goggles and whether the pilots were even looking in the right spot.

The American Airlines plane flying from Wichita, Kansas, collided with the helicopter 278 feet (85 meters) above the river, but the Black Hawk was never supposed to fly above 200 feet (61 meters) as it passed by the airport, according to the official route.

Before investigators revealed how high the helicopter was flying, Tim Lilley was asking tough questions about it at some of the first meetings NTSB officials had with the families. His background as a pilot gave him detailed knowledge of the issues.

''We had a moral mandate because we had such an in-depth insight into what happened. We didn't want to become advocates, but we could not shirk the responsibility,'' said Lilley, who started meeting with top lawmakers in Congress, Transportation Secretary Sean Duffy and Army officials not long after the crash to push for changes.

The NTSB has said the Black Hawk pilots may not have realized how high the helicopter was because the barometric altimeter they were relying on was reading 80 to 100 feet (24 to 30 meters) lower than the altitude registered by the flight data recorder.

Investigators tested out the altimeters of three other Black Hawks of the same model from the same Army unit and found similar discrepancies.

FAA controllers were warning about the risks all the helicopter traffic around Reagan airport created at least since 2022.

And the NTSB found there had been 85 near misses between planes and helicopters around the airport in the three years before the crash along with more than 15,000 close proximity events. Pilots reported collision alarms going off in their cockpits at least once a month.

Officials refused to add a warning to helicopter charts urging pilots to use caution when they used the secondary runway at Reagan the jet was trying to use before the collision.

Rachel Feres said it was hard to hear about all the known concerns that were never addressed before the crash that killed her cousin Peter Livingston and his wife Donna and two young daughters, Everly and Alydia, who were both promising figure skaters.