From 1970 to 1972 Helicopter Squadron Four and Helicopter 66 were embarked aboard USS Ticonderoga CVS-14, and By 1973 Helicopter Squadron Four, and Helicopter 66 with it, were embarked aboard USS Kitty Hawk.
That year, Helicopter 66 transported the Shah of Iran, Mohammad Reza Pahlavi, to Kitty Hawk for a shipboard visit while it transited the Indian Ocean.

At 7:00 p.m. on June 4, 1975, Helicopter 66, renumbered as '740', departed Naval Outlying Landing Field Imperial Beach near San Diego, California, en route to the U.S. Navy's Helo Offshore Training Area to conduct a regularly scheduled, three-hour nighttime anti-submarine training exercise.
During the operation, in which it was carrying a full complement of four crew, the helicopter crashed.
Though the crew was rescued by the U.S. Coast Guard, pilot Leo Rolek was critically injured and later died of the wounds he sustained in the crash.
The exact cause of the downing of Helicopter 66 is unknown; as of 2017 the U.S. Navy incident report remains largely classified.
The broken fuselage of the helicopter later sank in 800 fathoms (1,500 m) of water.
At the time of its crash, Helicopter 66 had flown 3,245.2 flight hours since being brought into service, and 183.6 hours since its last overhaul.

The submerged helicopter remains the property of the U.S. Navy, and a 2004 effort by private interests to recover it for preservation was not realized.
From 1970 to 1972 Helicopter Squadron Four and Helicopter 66 were embarked aboard USS Ticonderoga CVS-14, and By 1973 Helicopter Squadron Four, and Helicopter 66 with it, were embarked aboard USS Kitty Hawk. That year, Helicopter 66 transported the Shah of Iran, Mohammad Reza Pahlavi, to Kitty Hawk for a shipboard visit while it transited the Indian Ocean.
At 7:00 p.m. on June 4, 1975, Helicopter 66, renumbered as '740', departed Naval Outlying Landing Field Imperial Beach near San Diego, California, en route to the U.S. Navy's Helo Offshore Training Area to conduct a regularly scheduled, three-hour nighttime anti-submarine training exercise. During the operation, in which it was carrying a full complement of four crew, the helicopter crashed. Though the crew was rescued by the U.S. Coast Guard, pilot Leo Rolek was critically injured and later died of the wounds he sustained in the crash. The exact cause of the downing of Helicopter 66 is unknown; as of 2017 the U.S. Navy incident report remains largely classified. The broken fuselage of the helicopter later sank in 800 fathoms (1,500 m) of water. At the time of its crash, Helicopter 66 had flown 3,245.2 flight hours since being brought into service, and 183.6 hours since its last overhaul.
The submerged helicopter remains the property of the U.S. Navy, and a 2004 effort by private interests to recover it for preservation was not realized.
Helicopter 66