CAMP FOSTER, Okinawa — A Marine helicopter maintenance crew’s lack of sleep may have contributed to the failure to reinstall a cotter pin that led to the destruction of the $14.5 million aircraft.

The Aug. 13 crash of a CH-53D Sea Stallion on the grounds of Okinawa International University was caused by “maintenance malpractice,” according to a command investigation into the mishap.

“There was confusion on the flight line” in the hours leading up to the accident about the type of work that was performed on the helicopter the night before, stated Lt. Col. Winfield Scott Carson, a certified CH-53D pilot and graduate of the Naval Aviation Safety Officer’s Course, in the report.

Carson also noted that the maintenance department “was working too many hours per day to remain sufficiently alert to competently perform the demanding, meticulous maintenance required to operate helicopters.”

He recommended administrative action be taken against “those Marines responsible for failing to follow proper maintenance procedures leading to this mishap.”

The Marines were preparing to deploy for duty in Iraq and had been putting in extended hours to make sure the helicopters were ready. One member of the maintenance crew told Carson that he had put in three 17-hour days in a row.

A member of the day maintenance crew told Carson that when he arrived at the hangar, a corporal on the night crew asked for his help in working on the rotor blades.

“He asked me to come and give him a hand because he couldn’t hold his hand still due to lack of sleep,” the lance corporal told the investigator.

Carson submitted his report to Brig. Gen. Duane D. Thiessen, commander of the 1st Marine Aircraft Wing, on Sept. 27 and the report later was turned over to Japanese authorities. Stars and Stripes obtained a copy of the 210-page report from the Japanese Ministry of Foreign Affairs.

The helicopter, assigned to Marine Medium Helicopter Squadron 265, crashed after the tail rotor and a section of the tail rotor pylon “departed the aircraft,” Carson reported. He praised the three-man crew for their quick action in avoiding a nearby residential community and a soccer field where children were playing and attempting to set the helicopter down on the university campus.

“The entire aircrew reacted properly to the loss of the tail rotor and their immediate-action response preserved the lives of civilians on the ground and the aircrew themselves,” he noted.

However, the rotor blades of the helicopter struck the southern wall of the university’s administration building and the helicopter crashed and burned on impact with the ground.

No civilians were injured. The 30-year-old pilot sustained two fractured vertebrae, abrasions and burns. The 26-year-old co-pilot had a crushed left hand and multiple fractures and the 22-year-old crew chief, a corporal, had three fractured vertebrae, a deep puncture wound and facial trauma. Their names and details of their injuries were blacked out in the report.

Carson said the direct cause of the accident was the failure to re-install a cotter pin on a bolt in the tail rudder assembly during a routine adjustment on the tail rotor flight control.

“The bolt fell out on the downward leg of the landing pattern, which led to a loss of tail-rudder control,” Carson stated. “This caused a tail rotor blade to strike the pylon, the pylon subsequently failed, and the tail rotor departed the aircraft.

“This mishap was caused by maintenance malpractice,” Carson stated. “Specifically, the maintenance personnel did not comply with authorized procedures for rigging of the flight controls on the mishap aircraft.

“There was confusion on the flight line about whether they were performing a quick rig or a full rig,” he continued. “If a quick rig were being performed, the cotter pin would have never been removed from the bolt. If a full rig were being performed properly, the cotter pin would have been checked … at the completion of the job.

“In either scenario, this maintenance crew did not follow proper procedures for rigging the flight controls of the mishap aircraft,” Carson noted.

He placed the value of the helicopter, which was built in December 1970 and had a total of 7,295 flight hours, at $14.5 million.

Carson recommended that work-hour guidelines be established for aircraft mechanics with the 1st MAW and that “appropriate action be imposed on those Marines responsible for failing to follow proper maintenance procedures, leading to this mishap.”

On Oct. 1, Brig. Gen. Thiessen signed an endorsement of the report, indicating he directed his assistant chief of staff, Aviation Logistics Department, to “implement appropriate work-hour guidelines for all maintenance personnel in this command.”

However, he forwarded the recommendations for action against the Marines involved to Lt. Gen. Robert R. Blackman Jr., commanding general of the III Marine Expeditionary Force, since the Marines currently are deployed to Iraq and are no longer under his command.

“Based on the findings of the investigation, we are taking all kinds of steps to ensure something like this does not happen again,” said 2nd Lt. Eric Tausch, of Marine Consolidated Public Affairs. “Some of the steps taken include additional pre-flight checks, including having the pilots take a look at the part that failed.”

He said hours for the maintenance crews also have been revised, but he did not have the specifics. “You have to remember, being in the business we’re in we have to remain flexible,” he said.

He also said that the III MEF is “in the process of imposing appropriate administrative actions against some of the Marines involved for failing to follow procedures.”

“As far as when that will happen, or where they are now, I do not have that information,” Tausch said.

In conclusion to his endorsement of Carson’s report, Thiessen wrote: “This is a mishap that should never have occurred. The maintenance failure that led to this mishap could have and should have been prevented with proper leadership and supervision. Immediately after the mishap, this command initiated a sweeping review of all maintenance and other command procedures with a focus on enforcing accountability in all areas of operations.”

The general praised the crew of the helicopter “for their conscious decisions and actions to place themselves at greater personnel risk to minimize the risk to civilians on the ground.”

“Their actions to protect innocent lives were in keeping with the highest traditions of the Marine Corps,” he stated.

He also praised the Marines and Okinawa personnel who rushed to the scene, particularly the Ginowan Fire Department, the base fire department and rescue personnel, and Marines from the 1st Stinger Battalion, who saw the helicopter going down from the nearby Marine air station and climbed over fences to race to the accident scene and aid the injured crew.

Sign Up for Daily Headlines

Sign up to receive a daily email of today's top military news stories from Stars and Stripes and top news outlets from around the world.

Sign Up Now