“Indian radar may have been turned off at night.”
"Military systems, meanwhile, are often limited in their own coverage or just ignore aircraft they believe are on regular commercial flights. In some cases, they are simply switched off except during training and when a threat is expected.
That, one senior Indian official said, might explain why the Boeing 777 was not detected by installations on India's Andaman and Nicobar Islands, an archipelago which its planes were searching on Friday and Saturday, or elsewhere.
"We have many radar systems operating in this area, but nothing was picked up," Rear Admiral Sudhir Pillai, chief of staff of India's Andamans and Nicobar Command, told Reuters. "It's possible that the military radars were switched off as we operate on an 'as required' basis."