In the final moments before NewsChopper4 plunged into a parking lot in Chatsworth, the helicopter was still transmitting.
That recording has now become what the National Transportation Safety Board calls perhaps the “most important” evidence in determining why the aircraft suddenly went down on September 15, killing veteran pilot George Marciniw, aerial reporter Eliana Moreno and 29-year-old Edy Gutiérrez Mejia, who was on the ground. (NBC Los Angeles)
Investigators say two sounds in particular stand out: a noticeable change in the sound of the helicopter’s engine or rotor system, followed by warning tones from inside the cockpit. But those sounds are clues — not yet a final explanation for what caused the crash. (NBC Los Angeles)
The Helicopter Was Broadcasting Its Own Final Moments
NewsChopper4 had been hovering above Chatsworth while covering an earlier collision involving an SUV and a Metro bus.
The aircraft, a Eurocopter AS350 B2 operated by Angel City Air, was carrying Marciniw and Moreno when it suddenly lost altitude and crashed into a commercial parking area shortly before 7 p.m. (NBC Los Angeles)
Because the crew was actively covering a breaking-news scene, the helicopter’s camera and audio system captured part of the sequence leading up to the crash.
For investigators, that is extraordinarily valuable.
NTSB Investigator-in-Charge Fabian Salazar said officials want a pristine copy of the recording so specialists can conduct a detailed sound-spectrum analysis. (NBC Los Angeles)
Unlike casual listening, that analysis can allow investigators to study frequencies and changes in mechanical sounds that may provide information about what the helicopter’s systems were doing.
The First Clue: A Change in Mechanical Speed
The first sound investigators have publicly highlighted is a change in the helicopter’s mechanical noise.
Salazar said investigators can clearly hear sounds consistent with the engine changing speed. (NBC Los Angeles)
That doesn’t, by itself, establish that the engine failed.
Investigators still need to compare the recording with the physical wreckage, maintenance history and other evidence before determining exactly what happened.
But the timing makes the sound significant.
Aviation safety expert Jeff Guzzetti, who teaches at USC’s Viterbi Aviation Safety and Security program, separately described hearing what sounded like a winding-down noise shortly before the helicopter began descending. (NBC Los Angeles)
Then came the second sound.
The Second Clue: Warning Tones
According to the NTSB, the recording also contains cockpit tones that were likely advisories to the pilot. (NBC Los Angeles)
Guzzetti offered a more specific interpretation.
He said one prominent warning sounded to him like a low-rotor-RPM warning horn. Such a warning can indicate that the helicopter’s main rotor is turning too slowly. (NBC Los Angeles)
That distinction matters.
The NTSB itself has not yet publicly concluded that the tone was definitively a low-rotor-RPM warning or that low rotor speed caused the accident. Salazar described the sounds more cautiously as tones “likely” providing advisories to the pilot. (NBC Los Angeles)
So investigators now have a sequence they can examine closely: a change in mechanical sound, warning tones, and then the aircraft’s descent.
Why Rotor Speed Matters So Much
A helicopter depends on its main rotor blades moving fast enough to generate the lift necessary to remain airborne.
If rotor RPM drops substantially, the aircraft can lose lift.
But there are numerous reasons rotor speed could change, and hearing a warning on a recording does not establish which one occurred here.
Investigators therefore have to work backward.
Was there a problem with the engine?
The drivetrain?
Another mechanical system?
Or did something else happen that subsequently affected rotor speed?
Those are precisely the kinds of questions the NTSB investigation is designed to answer.
The agency says its examination will include the wreckage, maintenance records, weather conditions, pilot training, witness accounts and the recorded video and audio. (NBC Los Angeles)
Investigators Are Not Calling It an Engine Failure Yet
This is one of the most important distinctions in the early reporting.
The sounds may point investigators toward particular aircraft systems, but the NTSB has not announced a probable cause.
A preliminary interpretation by an aviation expert is not the same thing as an official finding.
Even a sound that resembles a low-rotor warning does not reveal why rotor speed may have decreased in the first place.
That could take months of analysis.
The NTSB typically releases an initial report relatively quickly, while a final report establishing probable cause can take considerably longer. (NBC Los Angeles)
The Helicopter Appeared Stable Before Something Changed
The available footage makes the sequence particularly striking.
Guzzetti said the helicopter initially appeared to be hovering normally. Then something seemed to change abruptly.
A witness on the ground gave a similar account from a different perspective.
Zareh Sevanesian told NBC Los Angeles that the helicopter appeared to be “swaying” before it began losing altitude. He recalled realizing that something didn’t look right as the aircraft continued getting lower. (NBC Los Angeles)
Moments later, it disappeared from his view behind buildings.
The helicopter ultimately struck a parking area.
The Pilot May Have Been Attempting an Emergency Maneuver
Guzzetti also pointed to the aircraft’s movement during its descent.
He said the helicopter appeared to descend while moving somewhat nose-down, a motion he considered potentially consistent with an autorotation landing. (NBC Los Angeles)
Autorotation is an emergency technique that can allow a helicopter to descend without normal engine power driving the main rotor. Air moving upward through the rotor blades keeps them turning as the helicopter descends.
But investigators have not yet established whether Marciniw was deliberately attempting an autorotation or exactly what conditions he was facing.
That determination will require much more evidence.
George Marciniw Was an Experienced Pilot
The questions surrounding the aircraft’s final moments are particularly poignant because Marciniw was a veteran aviator.
He had decades of helicopter experience and had also worked as a flight instructor.
On board beside him was Moreno, a familiar aerial journalist who had covered police pursuits, wildfires, severe weather and other breaking stories across Southern California.
The pair had gone up that evening to cover another tragedy.
They never returned.
A Man on the Ground Became the Third Victim
The crash also killed someone who had no connection to the helicopter.
Edy Fernando Gutiérrez Mejia was 29 and visiting Los Angeles from Cuilapa, Guatemala. His family said he had been in the city for only two days and had traveled there to purchase a vehicle that he intended to sell back home. (NBC Los Angeles)
When NewsChopper4 came down, Mejia was in the area below.
He became the crash’s third fatality.
Two other people were hospitalized after the accident, authorities said. (NBC Los Angeles)
The Recording May Ultimately Tell Investigators Much More
Audio evidence can reveal far more than words spoken inside a cockpit.
The NTSB explains that investigators can use cockpit sounds — including engine noise, warning alarms, clicks and other mechanical noises — to help reconstruct what an aircraft was doing and identify possible system changes. (NTSB)
That’s why investigators aren’t merely listening to NewsChopper4’s recording.
They want to analyze it scientifically.
Salazar said the recording will be sent to the NTSB’s laboratory for detailed examination. (NBC Los Angeles)
The frequencies hidden within those final seconds could potentially reveal information impossible to determine simply by watching the footage.
For Now, Two Sounds Stand Out — but the Mystery Remains
The sequence is disturbing in its simplicity.
NewsChopper4 appears to be hovering over a breaking-news scene.
The mechanical sound changes.
Warning tones can be heard.
The aircraft begins descending.
And shortly afterward, three people are dead.
Investigators now have to determine what connected those events.
The NTSB has emphasized that the video and audio are crucial evidence, but it has not yet determined why the helicopter crashed. (NBC Los Angeles)
For now, the changing mechanical sound and cockpit warnings are two of the clearest clues investigators have publicly identified.
Whether they ultimately reveal a mechanical failure, a loss of rotor speed stemming from another problem, or an entirely different sequence of events will depend on the investigation still underway.
What makes the recording so important is also what makes it so haunting: the helicopter may have captured the first audible signs of its own emergency.
For more on this tragic event, read about how Pilot George Marciniw Spoke to His Former Student Just Two Days Before Fatal News Helicopter Crash – Their Final Topic Now Feels Haunting. And for a change of pace, check out Julia Stiles Makes Long-Awaited TV Return With a Song Dolly Parton Personally Approved Weeks Before Her Death – but One Controversy Followed Her Into the Ballroom or Jean Smart, 75, Makes a Rare Red-Carpet Appearance With Teenage Son Forrest Five Years After Losing Husband Richard Gilliland.
