The commanding officer of the Marine squadron that lost 12 aviators in a helicopter accident off of Oahu’s North Shore was removed from his job three days before the tragedy because he failed to keep the unit operating at acceptable standards, a spokesman said.

Lt. Col. Edward Pavelka was relieved of command of Marine Heavy Helicopter Squadron 463 on Jan. 11, according to Capt. Timothy Irish, Marine Corps spokesman at Kaneohe Bay.

Pavelka did not commit misconduct, Irish said Friday.

Irish said Brig. Gen. Russell Sanborn, commanding general of 1st Marine Aircraft Wing in Okinawa, lost confidence in Pavelka’s ability to lead the squadron.

He was replaced by Lt. Col. Eric Purcell, who spoke at a memorial service honoring the aviators held Jan. 22.

Pavelka had assumed command of the helicopter squadron, whose nickname is Pegasus, 11 months ago.

Purcell said he told his squadron after the incident that his philosophy of command was “Mission first. Marines and families always.”

“Understanding the mission that they were doing is going to be critical to coming to terms with their absence,” he said. “Although the tragedy of this mishap cannot be denied, it wasn’t senseless. It wasn’t pointless.”

“By preparing for war and training under the most difficult circumstances, our military and the Marine Corps in particular creates an incredible deterrent to our nation’s foes. As our nation’s force in readiness, we — the Marines — must be ready for war when our nation is least ready for war.”

Two CH-53E Super Stallions were conducting routine night training when they apparently collided just before midnight Jan. 14 and crashed 2 miles off Haleiwa Beach Park.

All 12 Marines were killed. The Marine Corps has not said whether any of the bodies have been found, but debris has been located in 325 feet of water. A Navy salvage ship and a team of Navy divers are assisting in a recovery operation.

All the wreckage and debris recovered will be moved to Marine Corps Base Hawaii for analysis as part of the military accident investigation. Because the crash involved military helicopters, the National Transportation Safety Board is not conducting its own investigation.

The Coast Guard found four life rafts, but officials said none had been occupied.

Six Marines were aboard each aircraft — one instructor pilot was paired with a student pilot, and two instructor crew chiefs were paired with two students. Their training involved the use of night-vision goggles and a simulated scenario meant to practice loading and moving troops.

The helicopters were not conducting heavy-lift operations, Irish said.

The Super Stallion is the military’s largest, heaviest and most powerful helicopter, according to its manufacturer, Sikorsky. The aircraft can carry massive loads, according to the Marine Corps, including a 26,000-pound light armored vehicle, 16 tons of cargo or a large enough force of combat-loaded Marines to lead an assault.

The crash was the deadliest military noncombat accident in Hawaii history. It occurred less than a year after a Marine Corps tilt-rotor aircraft crashed during a training exercise at Bellows Air Force Station, killing two Marines. In 2011 one Kaneohe Marine was killed and three others injured when a CH-53D Sea Stallion chopper crashed on a sandbar in Kaneohe Bay in another training exercise.