Last Wednesday, a deadly tragedy struck Washington D.C. as a commercial passenger jet on approach to land at Reagan National Airport collided in mid-air with a passing U.S. Army helicopter, sending both aircraft and everyone on board plummeting into the icy Potomac River.

An investigation remains ongoing, but preliminary findings revealed discrepancies in recorded altitude for both aircraft and evidence suggests that the airliner pilots attempted to pull up to avoid the collision in the final seconds, Fox News reported.

Investigators are optimistic that the differing altitude readings for the two aircraft will be reconciled once the helicopter's waterlogged data recorder is fully probed and after the air traffic control tower's less reliable data readings are further refined.

Airline pilots attempted to avoid helicopter at last second

The Daily Mail reported that, according to National Transportation Safety Board officials, the pilots of American Airlines Flight 5342 made an unsuccessful last-ditch attempt to avoid the impending mid-air collision with the Black Hawk helicopter that inexplicably crossed its flight path at the same altitude while on approach to land at the airport.

"At one point very close to the impact, there was a slight change in pitch, an increase in pitch," NTSB official Todd Inman said of the commercial jet during a Saturday evening press conference.

In other words, the airline pilots attempted to pull up and increase altitude at the last second to avoid the helicopter but were unable to accomplish the heroic feat.

Discrepancy in recorded altitudes for both aircraft

Just the News reported that the NTSB further revealed to reporters that according to the plane's flight data recorder, it was flying at around 325 feet, give or take 25 feet, while the air traffic control tower's data suggested that the helicopter was flying at its maximum allowed altitude of 200 feet when the crash occurred.

However, per the Daily Mail, the tower's data is not believed to be reliable and information from the helicopter's flight data recorder have not yet been fully recovered, and there is reason to believe that it was flying higher than its 200 foot permitted ceiling in the vicinity of the airport.

It is hoped that eventual recovery of the helicopter's data and further refinement of the tower's data will clear up the discrepancy.

The NTSB's Inman noted that "obviously an impact occurred, and I would say when an impact occurs, that is typically where the altitude of both aircraft were at the moment."

Investigation and recovery operations still ongoing

"This is a complex investigation. There are a lot of pieces here," lead investigator Brice Banning said during Saturday night's press conference, according to the Daily Mail.

"The crew had a verbal reaction," Banning revealed of the commercial jet's pilots, and further shared how the aircraft's flight data recorder showed "the airplane beginning to increase its pitch. Sounds of impact were audible about one second later, followed by the end of the recording."

The outlet noted that full investigations by the NTSB typically take around a year or longer to complete, but the agency aims to release a preliminary report on what occurred within 30 days.

Meanwhile, efforts to make a "dignified recovery" of the bodies of all 67 victims -- 60 passengers and 4 crew members on the plane, three soldiers on the helicopter -- and to retrieve all of the wreckage of both aircraft from the river remain ongoing with the use of high-definition cameras, divers, salvage crews, and cranes on barges.