If the transponder was not accessible from the cockpit then how would the pilots enter the squawk - I had around 4 different squawks coming back from China last night and how would they ident when asked by ATC?
Would that B777 have Sat phones or internet aboard for PAX use - surely if a hijack was the case someone would have made a call. If it landed somewhere, someone would have got a phone signal. My phone often gets a signal below FL80 if i forget to turn it off.
Could a hostie have been last person alive, like the Helios 737 depresurisation, have been trying to tune a radio to request help and accidentally turned off the XPNDR? Knocked he controls and sent it off course
How much fuel was ordered? Flight Plan fuel or a load more to take it somewhere? If you were going to Hijack your own A/C then surely you'd take more fuel?