Malaysian Airlines MH370 contact lost

[Machinbird]

Oxygen Saturation

It has been a few years since my last low pressure chamber run, but here is what I remember:

Above FL350, even breathing 100% oxygen will not keep your blood oxygen level up and you must pressure breathe.

Pressure breathing is a lot of work and very unnatural, but can keep you going at altitudes of up to 50,000 feet for up to 30 minutes.

If one of the crew or a bad guy had access to pressure breathing equipment, then the climb to high altitude as reported by NYT informant makes ominous sense as a means to disable and possibly terminate all others in the aircraft.

Radar signals recorded by the Malaysian military appeared to show that the missing airliner climbed to 45,000 feet, above the approved altitude limit for a Boeing 777-200, soon after it disappeared from civilian radar and turned sharply to the west, according to a preliminary assessment by a person familiar with the data.
The radar track, which the Malaysian government has not released but says it has provided to the United States and China, showed that the plane then descended unevenly to 23,000 feet, below normal cruising levels, as it approached the densely populated island of Penang.

http://www.nytimes.com/2014/03/15/wo...r.html?hp&_r=0

I concur with the first part of post 4377 by xcitation

Assuming the hijack hypothesis are we talking a very skilled pilot with planning or an extremely lucky amateur?

Data points:

Precise timing of disappearance at the minute when switching between Malaysia and Vietnam airspace.
FL450 excursion when heavy requires skillful handling at performance limits (maximum energy climb). [contested by some posters with experience on type. However service ceiling is not absolute ceiling!]
Cruise at FL295 which avoids outbound/inbound traffic.
Follows border between Thailand/Malaysia when crossing peninsula.
Minimal air defense monitoring at night - opportunity to leave the area before dawn when full air defense is active.
A/c avoids areas with active radar coverage.

I speculate that the path chosen afterwards depends on the motivation of the hijacker. If a suicide plan, he took the Southern route.
If there was high value cargo, then he took the Northern route.

The Malaysian authorities should have the data for that logical decision point.