It lost FULL radar contact at 35,000 feet... over WATER.
Where it was lost there is NO radar contact, The radar gap if you will, is about 100 nautical miles wide, VHF contact in also not available for 10 minuntes or so. Communication during this period is via HF (problamatical) or increasingly often via "ADSB", bascially satellite communciation.
The only thing that could cause that is a total failure of the aircraft's integrity. Explosive decompression... or more likely, a bomb. The signal would register a major drop in altitude before disappearing as the plane broke up after a structural failure. Or the pilots would inform ATC of a problem. This would have to have been sudden, and catastrophic failure of the aircraft decreasing the mass of the aircraft instantly and cutting all power to communications and the transponder.
Basically correct,
Seeing as it operates on the Boeing system it could be the old Hawaii airlines syndrome. (Dad and I never miss Air Crash Investigations) Its operating in Asia. Lots of short hops and constant pressurizing and depressurizing causing cracks that results in explosive decompression. But Malaysian airlines has an outstanding safety record. They have had almost NO accidents in their operational history.
It is a 777, not the venerable 737, the 777 would be lucky to do 3 sectors a day, only if they did a Kuala Lumpur to Singapore and back would the flight time be less than an hour, everything else close around 90 minutes or so, mostly sectors of 6 -10 hours. Very unlikely multiple cycles whould be the problem. When you look at their 737-300/400 series, which I personaly saw enter service back in the early 90's those aeroplanes operated 6-8 sectors a day in the kind of environment that you prescribe to the Hawaii Airlines syndrome, the last of those planes were phased out last year or the year before. They didn't have any issues with cycles (that I know of).
My best guess would be that the stolen passports are actually the beginnings of this. It may be a red herring I know "but if you eliminate all possibilities the impossible however unlikely must be the truth".
Which class were they booked in? If it was economy it would be very difficult to effect entry to the cockpit as they have to pass unchallenged through business class. However if brute force was used, anything is possible, Im leaning this way.