On 10 May 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).
[1] It is still the worst single-aircraft accident in Israel.
The crash site was in the West Bank, about 5 kilometers north of Jericho in a wadi.
The cause was determined to be flying at too low an altitude during the dark, which caused the helicopter to strike a hill, crash and explode (CFIT, Controlled flight into terrain).
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