‘The FAA issued an Airworthiness Directive (AD) on September 26 asking that additional checks on the Boeing 777 fleet worldwide be conducted during scheduled maintenance .

“This proposed AD would require repetitive inspections of the visible fuselage skin and doubler if installed, for cracking, corrosion, and any indication of contact of a certain fastener to a bonding jumper, and repair if necessary,” the transport authority wrote in the AD found online.

“We are proposing this AD to detect and correct cracking and corrosion in the fuselage skin, which could lead to rapid decompression and loss of structural integrity of the airplane.”

The FAA explained that the first crack was discovered on a 14-year-old plane with some 14,000 total flight cycles by an operator during a maintenance planning data inspection. ‘

(A) Boeing may have mistakenly confused the fact that Malaysian air HAD the equipment onboard, including the antenna under which the crack was found, with the fact that the airline did not have a data contract with the company – and told the airline that no inspection was necessary when it actually was.  To me, this is the most likely scenario because Boeing has actually said publicly that this aircraft was exempted from the inspection because it didn’t have the SATCOM antenna installed. But it must have or no ‘pings’ would have been transmitted to Inmarsat.
(B) Malaysia airlines either did not do the check during the scheduled maintainance earlier this year, or whoever was supposed to do it didn’t and signed it off.  The aircraft was coming off lease May 31 and the airline might have been skimping to save money, or someone was just lazy.
The aircraft experienced a rapid decompression at 35,000 feet. Above 35,000 feet one pilot is required to wear an oxygen mask at all times but this requirement may not apply in Malaysia and is routinely disregarded everywhere else.
It was the middle of the night and one pilot was almost certainly asleep. The aircraft was likely on autopilot. A rapid decompression would dis-orient and disable both pilots within seconds.  Fifteen seconds.
If the aircraft pitched upward, the time could have been as short as 5 seconds.  The windows would have fogged instantly.  The temperature would have dropped to ~40 degrees below zero within that same 7 to 15 second period.
Even IF one of the pilots was awake and at the controls instead of being in the bathroom or getting coffee, if he was not wearing an oxygen mask, and I guarantee he wasn’t, he would have had no chance.
If the aircraft maintained structural integrity and the auto-trim was engaged, it could concievably have recovered at some altitude and continued to fly with the crew and passengers dead until it ran out of fuel, even with the autopilot off.
This explains why the reports of ‘pings’ are plausible and why the aircraft could have descended to an unknown altitude but maintained flight and flown into eternity. It is unlikely, but it fits the facts as I understand them.
It also explains why Malaysia and Boeing are so anxious to call this a terrorism incident or pilot suicide. They are covering up their liability.