STRATFORD, Conn., July 23, 2013 /PRNewswire/ -- Sikorsky Aircraft Corp., a subsidiary of United Technologies Corp. (NYSE:UTX), has delivered the 400 th MH-60 SEAHAWK ® helicopter to the U.S. Navy. The milestone consists of 166 MH-60R anti-submarine and anti-surface warfare helicopters, and 234 MH-60S utility/armed helicopters. The Navy took possession of the 400 th, an MH-60R aircraft, on June 24. (Logo: http://photos.prnewswire.com/prnh/20060403/SIKORSKYLOGO ) "MH-60 multi-mission aircraft are among the most reliable and sophisticated maritime helicopters in the world," said Capt. James Glass, Navy Program Manager, H-60 Programs. "The Navy intends to continue flying these helicopters well into the 2030s." MH-60S ("Sierra") helicopters carry supplies and sailors between ships, and protect U.S. ships from surface threats in an armed configuration. Sierra aircraft are expected to take on an airborne mine countermeasures role starting in 2014. MH-60R ("Romeo") helicopters employ radar, acoustic sonar, communications links, torpedoes and air-to-surface missiles for the anti-surface and anti-submarine warfare roles. Sierra aircraft, which entered U.S. Navy service in 2002, will remain in full rate production through 2015 as part of a currently planned production run of 275 aircraft. Romeo helicopters, operational since 2006, are currently scheduled to remain in production through 2017 to meet the Navy's 291 intended aircraft buy. The two aircraft models have accumulated a combined 660,000 flight hours to date. "Mission success in the harsh maritime environment is a testament to the men and women of the U.S. Navy who fly and maintain these SEAHAWK aircraft," said Dave Zack, Sikorsky Maritime Programs Director. "The skilled workforce at Sikorsky, and our supplier teammates, remains committed to building and supporting the world's most reliable, durable and operationally effective maritime helicopter." All but two of the 400 MH-60 SEAHAWK aircraft delivered to date are operated by the U.S. Navy. In 2011, the Royal Thai Navy took delivery of two MH-60S helicopters via the U.S. Government's Foreign Military Sales (FMS) program.