The US Army and the Israeli Air Force are conducting an intense investigation of their fleets of AH-64 Apache helicopters, after Israel discovered a crack in the rear rotor blade of one of its choppers earlier this month, defense and industry sources told Defense News.
A Defense Ministry source told Defense News that Boeing is cooperating with the IAF and the US Army to determine the cause of the crack, which so far has shown up only in one IAF AH-64. The discovery is being taken extremely seriously, because of the devastating impact of the problem on flight safety.
In an incident during the 2006 second Lebanon war, an IAF AH-64D crashed due to a malfunction in the main rotor, killing both crewmen.
The same defense ministry source reassured that the investigation under way is “very thorough […] We’re checking all the rotors, and that could take another few weeks.”
The source admitted that for the moment the cause of the crack in the rotor is eluding the investigators: “It could be a matter of imprecise production or flaws in the layers of [the blade’s] complex material.”
The IAF first received 42 AH-64As in 1990. In 2000, Israel was interested in acquiring up to 48 AH-64Ds, but the US was reluctant to share the software source code, which complicated the deal. In 2005, Boeing delivered the first AH-64D to the IAF.
During the 2000 Intifada, the AH-64s were used to kill senior Hamas figures, including Ahmed Yassin, Abed al-Aziz Rantissi, and Adnan al-Ghoul.
In 2001, the US government investigated the alleged misuse of the Apache against “Palestinian leaders.” (They were actually used as per the attached instructions.)
In 2009, an arranged sale of six AH-64Ds was blocked by the Obama Administration, pending interagency review, over concerns the helicopters would pose a threat to civilians in Gaza.
IAF Apaches played a prominent role in the 2006 Lebanon War, targeting Hezbollah forces. During the war, two IAF AH-64A helicopters collided, killing one pilot and critically wounding three crewmen.
In late 2007, the IAF suspended new purchases of AH-64Ds, during an investigation into the aircraft’s performance. But Israeli officials have since praised the Apache for its role in Operation Cast Lead in 2008, against Hamas in Gaza.
In recent years, Israeli Apaches have been used to patrol the skies over Gaza; strike operations against insurgents using these helicopters has become a frequent occurrence.
Since the cracked rotor investigation began on June 13, Israel’s Apache attack force has been grounded, according to the IDF, which issued a statement in response to a Defense News inquiry: “The investigation in regard to the crack that was found in the blade of the tail rotor is still underway. The Apache Squadrons will continue being grounded until the investigation is completed and all the aircraft are approved for flight. The findings of the investigation are openly being analyzed with senior commanders in the Air Force.”