The Navy yesterday issued a temporary grounding bulletin on six Marine Corps UH-1Y and one AH-1Z helicopters until the aircraft have been inspected for potential faulty components in each aircraft’s transmission gearbox, a source familiar with the program said.
This grounding bulletin is a precautionary measure, the source said.
Aircraft found to have faulty components would remain grounded until replacement gearboxes are delivered and installed. An engineering root cause and corrective action investigation continues, according to the source.
Bell Helicopter Textron [TXT] makes both the UH-1Y and the AH-1Z.
“The affected aircraft’s gearboxes sustained significant damage and need to be replaced. Each gearbox costs $1.1 million. Overall repair and replacement costs will be ascertained once the investigation and extent of needed repairs are determined,” the source added.
The faulty bearing retainers will have minimal impact on production. The main rotor gearbox is field replaceable, and the aircraft production line can accommodate an out of sequence installation. The process to manufacture bearing retainers is a relatively straightforward process that uses commonly availably raw material, the source said.
Additionally, there are currently nine retainers in stock, and two suppliers that manufacture these components. Both fleet replacement and production gearboxes can, and will, be manufactured simultaneously. Contractual aircraft deliveries are more than four months ahead of schedule, with the next delivery slated for September 2009, the source said.
The H-1 upgrades program continues to be the critical program for the Marine Crops rotary-wing utility and attack aircraft. The two platforms are 84 percent identical, which maximizes efficiency and maintainability. Additionally, the incorporated upgrades provide considerable superior capabilities compared to their legacy predecessors and are extremely effective platforms in irregular warfare environments.