By Peter Apps and Frank Jack Daniel LONDON/NEW DELHI (Reuters) – Whatever truly happened to missing Malaysian Airlines flight MH370, its apparently unchallenged wanderings through Asian skies point to major gaps in regional – and perhaps wider – air defences. On Saturday, Malaysia’s Prime Minister Najib Razak said authorities now believed the Boeing 777 flew for nearly seven hours after disappearing early on March 8. Either its crew or someone else on the plane disabled the on-board transponder civilian air traffic radar used to track it, investigators believe. It appears to have first flown back across the South China Sea – an area of considerable geopolitical tension and military activity – before overflying northern Malaysia and then heading out towards India without any alarm being raised.