Audio from an air traffic control tower at Northeast Philadelphia Airport reveals the horrific moments before a medical ambulance plane crashed in Philadelphia Friday night while transporting a pediatric patient.

The audio, obtained by Fox News Digital, was recorded moments before the plane took off. Operators can be heard speaking as they desperately tried to make contact with the Learjet 55 before it crashed. 

“What’s going on down there?” one air traffic controller can be heard saying. 

“We have a lost aircraft. We’re not exactly sure what happened. So, we’re trying to figure it out,” replies another air traffic controller. “The field is going to be closed so no inbounds-outbounds.” 

John Anderson, a retired pilot from Philadelphia, told Fox News Digital that, based on the video of the crash and the way the aircraft struck the ground, the likely cause was a takeoff stall. 

“The plane was out of the crew’s control. It was not controlled flight into terrain (CFIT). May have been a mechanical malfunction of the stabilizer, elevator, trim or even a load shift rearward within the cabin,” Anderson said. 

He further speculated that if “it was a medical flight with a stretcher on board and the stretcher was not properly secured, it may have rolled rearward.” 

Police vehicles block the area surrounding the site of a plane crash in Philadelphia, Pennsylvania, U.S., January 31, 2025.  (Rachel Wisniewski/Reuters)

“This would cause the nose to raise and stall the wing. In that case, the nose will drop with the angle in the video,” he said. “Because it was right after takeoff and the initial climb, I would say it was likely aswing stall. There could be a number of factors that would cause a stall. Could have been a runaway trim, malfunctioning stabilizer.”

Friday night’s disaster comes just barely 48 hours after a deadly collision between an American Airlines flight and an Army helicopter near Reagan National Airport that resulted in the deaths of 67 people. 

Fox News Digital’s Jenny DeHuff and Alexandra Koch contributed to this report.