|Date||May 10, 1977|
|Aircraft type||Sikorsky CH-53 Sea Stallion|
|Operator||Israeli Air Force|
On May 10, 1977, an Israeli Air Force Sikorsky CH-53 Yas'ur helicopter crashed during an exercise in the Jordan Valley, killing all 54 on board (including the 10-member flight crew). The disaster became known as Ason Hanun-dalet, or "Disaster of the 54".