The Air Force's investigation into the May 2 crash of the Puerto Rican National Guard WC-130 near Savannah, Georgia, could take months to complete, but the rare video footage of the crash offered clues to experienced C-130 pilots such as Dusty Cook, a former Marine Corps major who flew the venerable four-engine, turboprop aircraft for more than 10 years.
"It looked like it was a critical engine failure ... like the number one engine failed and just this dynamic rollover," Cook told Military.com. "It looks like it lost lift and it lost power on the left side, and that is why I am assuming it was the number one engine.
"It's shocking to me; the C-130 has been one of the safest airplanes."
Analyzing a Crash
But this is the third crash involving the C-130 Hercules to occur in the past two-and-a-half years.
A Marine Corps KC-130 crash in Mississippi on July 10, 2017, killed 15 Marines and one Navy corpsman. And on Oct. 2, 2015, an Air Force C-130 crashed at Jalalabad Airfield in Afghanistan, killing six airmen.
To put the figure in context, the last time an American variant of the workhorse aircraft had sustained a deadly crash before that was in 2012, when an Air Force C-130H crashed in South Dakota while fighting a fire, killing four of the six crew members on board.
The Jalalabad crash was determined in 2016 to be a tragic case of pilot error.
A cause has yet to be released for the KC-130 crash last year. But immediately following the crash, officials indicated that, as with the most recent crashes, it appears something went wrong in midair that resulted in the deadly disaster.
"Indications are, something went wrong at cruise altitude," Brig. Gen. Bradley James, commander of the 4th Marine Aircraft Wing, said at a press conference days after the Mississippi crash. "There is a large debris pattern."
The close-knit C-130 community was quick to dissect the dramatic video footage from the most recent mishap to learn why this beloved aircraft with a reputation of safety and reliability is crashing.
Pilots routinely train for emergency mishaps such as engine failure, so why did the plane roll over? Was it the age of the aircraft, which was on its retirement flight? Was it poor maintenance? Or was it somehow related to the massive defense spending cuts under sequestration, a crippling budgetary bind that so many generals warned against?
"I have studied hundreds of aircraft wrecks. Every wreck is different, and every wreck is the same," said an active-duty C-130 pilot of 20 years, who preferred to remain anonymous for this article. "When the safety investigation comes out, we will know exactly what happened."
Evidence of Engine Failure
Having watched the video of the May 2 crash, the active-duty pilot said he believes the aircraft lost two of its four engines.
"The way the plane is coming down, it looks like he didn't have power on his number one and two engines, which are the engines on the left side," the pilot said, referring to Maj. José R. Román Rosado, the plane's pilot who was killed in the crash.
"That's your worst-case scenario on that airplane, because the hydraulic pumps are attached to your engines. It's part of your accessory drive housing and those hydraulic pumps on the left side. They help you with your flight control boost," he added.
Think of it as power steering for a car, except it's "way easier to drive a car without power steering than it is to fly an airplane without the airplane version of power steering," he said.
"If he lost both of those engines, which is my theory that he did, he didn't have power steering and he had no way to quickly get his pumps in gear," the active-duty pilot said, explaining that those pumps control the flaps and landing gear.
The C-130 has two large propeller engines on each wing, which force air over the wings and create lift.
"The beauty of the C-130 is those propellers create air. ... So if those engines stop running on one side, they are no longer producing lift, so that side will naturally want to lower, and the other side naturally wants to raise because that wing is getting lift," the active-duty pilot said.
Pilots are required to train for at least one week a year in flight simulators that focus on emergency procedures, such as how to turn away from dead engines, causing the wing with lift to lower and the wing without lift to rise.
"I want to get that [left] wing up, because otherwise your plane is going to naturally just want to roll over," the active-duty pilot said.
The video footage clearly shows the plane rolling over to the left before it crashed. Both pilots told Military.com that they did not rule out pilot error, but said the circumstances of this crash, while not impossible, would be difficult to recover from.
"When you reach a certain bank angle, you're just not going to recover," the active-duty pilot said. "If you are not thinking about a lot of things that can happen or you're nervous or things are kind of getting out of control quickly ... it's going to flip over."
An Aging Aircraft
On top of possible engine failure, there were other circumstances that could have contributed to the crash.
"Technically, there are many things you've got to take into account," Cook said.
The aircraft had just taken off from Savannah/Hilton Head International Airport and was headed to Davis-Monthan Air Force Base in Tucson, Arizona.
The hot, humid weather in Savannah would have created "higher density altitude conditions," forcing the aircraft to perform as if it were flying at a higher altitude, Cook said. This would have hindered the aircraft's performance, making it harder for it to gain lift at a slower takeoff speed.
"So it's hot and they just took off. When you are going to take off to fly to Arizona to Davis-Monthan, odds are they had a lot of gas on board, so that means they are heavy," Cook said. "So those are two bad things to be when you have something really bad happen."
The WC-130, which belonged to the 156th Airlift Wing out of Carolina, Puerto Rico, was on its final flight. The aircraft was first reported to be more than 60 years old, but Air National Guard officials later said it was closer to 40 years old.
C-130s typically go in for heavy, depot-level maintenance every few years, so age may not be a factor in this case.
"The only thing that matters to me about age is the frame," Cook said, explaining that G-level stress and metal fatigue can cause problems.
"When you are talking about the power plants and the engines and their operability ... that is just good maintenance or bad maintenance.
"The engines always have to work, and you have more emphasis put on those engines than really anything else in the airplane," he said.
There are many conditions that could lead to engine failure on a C-130, pilots say.
If the "fuel flow was interrupted because of a maintenance function or you could have sucked a bird down the intake, that is an actual emergency," Cook said.
"All the maintenance forms, all the actions, all that stuff ... on the National Guard side and the Air Force side -- they are going to track down, like, what they did and what the maintenance action forms said."
The active-duty pilot told Military.com that he "would be surprised if this aircraft had a poor maintenance record."
"National Guard planes typically are way better maintained than active-duty planes because you've got the exact same crews working on the exact same aircraft for years, and they are really good at it," he said.
"Every plane has its little glitches. Every plane has its little quirks. When you've got a guy that's been working on the same airplane for about 20 years, he knows that airplane better than he knows his children," he said.
On May 7, the Air Force directed its active-duty wing commanders to conduct a one-day pause in flight operations for a safety review to look for trends that may have led to a spike in Class-A mishaps, which are accidents that result in fatalities or more than $2 million in damages to an aircraft.
As of May 2, Air Force officials said that the number of manned aviation Class-A mishaps has increased by 48 percent in fiscal 2018.
Disastrous Budget Cuts
If there is one factor that C-130 pilots believe has contributed to aircraft accidents over the past several years, it's sequestration.
The automatic, across-the-board spending cuts first began in 2013 and were designed to cut $1 trillion off the deficit over a decade. About 50 percent of the cuts targeted the Defense Department, prompting U.S. military leaders to warn Congress of its damaging effects on flying hours, maintenance and other measures of readiness.
Congress agreed to a budget deal that would spare defense spending from sequestration cuts in fiscal 2018. Lawmakers are currently working on the same type of spending deal for the proposed fiscal 2019 budget but, officially, sequestration still exists until 2023.
Cook is certain that it had an effect on depot-level maintenance "where we have our very skilled artisans" perform critical work on aircraft.
"When sequestration occurred, a lot of talent left ... a lot of people did not want to deal with bureaucracy and getting paid, things like that, so they left," he said.
Cook himself recently resigned his commission for the same reason, he said.
"I love the Corps. I'd still be a Marine right now; I'd still be flying right now if I knew that sequestration was not going to negatively affect our fleet. So this was a risk decision that I took to resign my commission and get out," Cook said.
The active-duty C-130 pilot agreed about the dangers of sequestration.
"I do believe, and I think the data shows, that there has been an upward trend in aircraft mishaps since sequestration, across the board," he said.
Cook doesn't fly C-130s anymore, but his confidence in the aircraft isn't shaken since it is "shared by every service and almost by every nation," he said.
"Everybody shares it; we have had a pretty good track record of safety," Cook said.
"We have had the greatest track record, the best people flying it. It doesn't matter if it's the Puerto Rican National Guard or the United States Marine Corps or the Indonesian Air Force, if a C-130 crashes ... it really hits close to home.
"Even though I am out, my ownership just doesn't go away. My pride in the airframe doesn't go away," he added.
Editor's Note: This story has been updated to clarify the effect of "higher density altitude conditions" in paragraph 28.
-- Military.com's Oriana Pawlyk contributed to this story.
-- Matthew Cox can be reached at firstname.lastname@example.org.