The U.S. Marine Corps has begun a full reset of its CH-53E helicopters to address an issue that came to light after a fatal 2014 crash, the Navy said Wednesday.

The work on 147 of the aging Super Stallion heavy lift aircraft is aimed at increasing the number of operationally fit aircraft and addressing systemic issues that have in recent years driven the platform's readiness to unsustainable depths, Naval Air Systems Command said in a statement.

Issues with the aircraft first came to light following the January 2014 crash of an MH-53E Sea Dragon, the Navy's version of the helicopter, off the coast of Virginia during a training exercise.

Three of the five sailors on board were killed, and the subsequent investigation found that electrical wires had chafed against and breached a fuel line, sparking a fire that flooded the cabin and cockpit with thick smoke, NAVAIR said.

That prompted an inspection of all CH/MH-53s for signs of chafing.

"What was discovered was that the material condition of the aircraft, both the CH-53E and the MH-53E, was degraded," Col. Hank Vanderborght, program manager for the H-53 Heavy Lift Helicopters Program Office at Naval Air Systems Command, said. "Those helicopters have been around since the early 80s, so 30-plus years, and we'd been at war [on terrorism] for the last 15 years, so the machines had been used pretty hard."

The reset will take three years, NAVAIR said.

Every aircraft will be put through an average 110-day process of stripping the aircraft down, rebuilding it and changing out any high-time components.