By YAAKOV KATZ
Due to large size and impressive versatility, the Yasour transport helicopter is still believed to be the most reliable aircraft of its kind in the IDF, even after more than 40 years of service and the regular mechanical checkups it requires.The Yasour – Israel’s name for the Sikorsky CH-53 – was first integrated into IAF service in 1969 after being bought from the United States. It is used regularly by the IAF’s 669 Search and Rescue team, and is known for legendary missions such as the 1973 airlift of over 600 soldiers to the peak of Mount Hermon, where they recaptured it from the Syrians.RELATED:Report: 6 IAF men dead in Romania chopper crashThe helicopter is the IAF’s primary aircraft for transporting soldiers – it can carry 35 with all their equipment – and was used extensively during the Second Lebanon War in 2006. One Yasour helicopter was shot down by Hizbullah during the war.In 2007, the IAF began a new upgrade program for the helicopter called “Yasour 2025,” under which it installed over 20 new electronic systems including, for the first time on helicopters, one for missile defense.The upgrades are meant to extend the life of the Yasour until 2025, and have cost the IAF tens of millions of dollars. The last major fleet upgrade was done in the late ’90s and was outsourced to a local defense industry.The helicopter that crashed in Romania on Monday was from Squadron 118, which is based at the Tel Nof air base. Also called the “Night Birds,” the squadron has taken part in all of Israel’s recent major operations and wars, particularly in ferrying special forces into enemy territory.During the Second Lebanon War, the squadron flew commandos from the IDF’s General Staff Reconnaissance Unit – known as Sayeret Matkal – to the Bekaa Valley in Lebanon, where they participated in an operation against Hizbullah. During Operation Cast Lead, the squadron evacuated 11 soldiers from the Gaza Strip.For the IAF, there really is no replacement for the Yasour. One option reviewed by the IAF was Boeing’s V-22 Osprey, a tilt-rotor, vertical/short takeoff and landing (VSTOL) multi-mission aircraft developed to ferry soldiers, and particularly special forces, deep behind enemy lines. The aircraft has revolving rotors on its wings that enable it to take off like a helicopter and fly like a plane.The crash on Monday was not the first incident involving the Yasour helicopter.On February 4, 1997, two helicopters collided in midair in foggy weather conditions, and 73 soldiers were killed, leaving no survivors. The crash was the worst air disaster in IAF history.