New Delhi, Feb. 4 -- Investigators have found that a rare failure of a critical part in the transmission system caused the crash of a coast guard Dhruv advanced light helicopter (ALH) at Porbandar in Gujarat on January 5, and a high-powered panel has been constituted to determine the reason for the breakdown of the component before steps can be initiated to fix the problem and declare the fleet airworthy again, two officials familiar with the matter said on Monday. P10...