IAF finds last year’s helicopter crash was caused by faulty relay switch

The Israeli Air Force on Friday accused Lockheed Martin, the manufacturers of the Yasur heavy transport helicopter, of failing to inform the military of a defect in a component of the aircraft, which caused one of the helicopters to catch fire and require an emergency crash landing in a field in southern Israel late last year.

On November 26, the pilots of the Sikorsky CH-53 Sea Stallion helicopter with 14 people on board were forced to make an emergency landing after the aircraft caught fire during a training flight. Everyone on board escaped unscathed, but the helicopter was completely destroyed.

On Friday, a team led by an air force colonel completed its investigation of the event and presented the findings to IAF chief Maj. Gen. Amikam Norkin.

The team found that the initial fire was caused by a malfunction in one of the relays leading to the aircraft’s left motor, “which caused the helicopter to catch fire,” the military said in a statement.

“Despite the fact that this malfunction had been identified by the company, the information was never passed along to the air force. The investigatory team also found that the air force’s maintenance procedures did not find the malfunction in the relay,” the IAF said.

Lockheed Martin, which owns Sikorsky, said it was looking into the matter.

“Sikorsky continues to work with the Israeli Air Force investigation authorities in respect to this incident. We will share any verified actionable information with the operating fleet. At this time we have no further comment,” he said.

IAF chief Norkin said the malfunction was an irregular one, but that he believed that every accident is preventable. As such, he called for the creation of new maintenance protocols in order to find such issues in the future.

Norkin also again credited the pilots’ quick actions — landing the helicopter in under a minute — with allowing all 14 soldiers on board to escape unharmed.

Israel’s fleet of Yasur helicopters were grounded for just over a month following the emergency landing, returning to service in early January.

The aging helicopters, which were purchased from the United States in the late 1960s, are due to be retired in the coming years, though a replacement aircraft has yet to be chosen.

In 2010, an IDF Yasur helicopter crashed during a joint exercise of the IAF and Romanian Air Force, killing the five people on board.

That crash was found to have apparently been caused by human error.

In 1997, two Yasur helicopters collided in the air while en route to locations in the country’s then-security zone in southern Lebanon. Seventy-three soldiers were killed in what was Israel’s most devastating air disaster.