India’s CAA Mulls Mandating Dhruv Airframe Mod

India’s civil aviation authority, the DGCA, is considering grounding all Hindustan Aeronautics (HAL) Dhruvs until the airframe is modified around the intermediate gearbox (IGB) in the tail fin. In some helicopters, “cracks were observed on the rib bottom of the IGB [and an associated area],” according to a proposed airworthiness directive issued in March. The DGCA proposes strengthening the IGB on both in-service and in-production helicopters. These modifications have been documented since October 2010.