Airliner missing between Malaysia and Cambodia/Vietnam, terrorism possible

[Biggus]

Lets say that there was a fire,

1) why no Mayday? Aren't there backup comms systems? Aren't there automatic systems that would communicate a fire on board?

2) why the continued course changes? I suppose the system could have continued to degrade, but it seems odd (assuming there is any credibility to the radar information, a dangerous assumption based on recent events).

Priorities in order of importance are to aviate, navigate and then communicate. From the perspective of the crew, an electrical fire is going to result in immediately depowering large chunks of avionics and comms equipment and then powering one thing at a time back up until the relevant system is found. The system you'd expect to automatically report a fire to the outside world is ACARS, and we know that didn't work for whatever reason.

No mayday could be easily chalked up to either being overtaken by events in fighting the fire or the fire knocking the radio comms out. There are a number of different radios onboard, but the breakers would be pulled at the same time.

Course changes beyond the radar tracking are likely to be the aircraft following the active plan in the FMS, whatever that might have been. Like I hypothesised earlier, getting off the airway while troubleshooting items that include the transponder would be a key priority. Punch in a few nearby waypoints that sound reasonably acceptable (and under increasingly hypoxic conditions, strange things can sound reasonably acceptable) and begin dealing with the fire/decompression/whatever.

Or the radar tracking is disinformation or a cover to explain how the aircraft got to it's present position without compromising someone's capability.

Assuming the fire scenario, and the pilot/copilot had enough time to turn the plane, would they not also place the plane on a glide path to the airport, or does that require too much additional data entry?

From their last tracked position, going back to KL would mean clearing some obstructions on approach. Langkawi was the nearest reasonably safe approach available at the time, from what I understand. That's the direction the aircraft was initially heading.

Wouldn't the pilot call out some type of mayday call signal to alert the airport of an emergancy landing?

As I've said above, communication is third priority in line after getting a handle on aviation and navigation. If ACARS VHF and HF datalinks are out, voice comms are probably out too, but that shouldn't matter too much, because there are lost comms procedures. How these lost comms procedures work with loss of transponder, I don't really know.

I think it's extremely important to point out that this scenario is basically a one-in-a-million perfect storm, if this is what has happened.

This plane is now in the twilight zone and we will probably never have near-consensus on what happened, but I was thinking: all this speculation must have given several people some very interesting new ideas...

Probably true.


Something else that I've found interesting today is the relationship between Malaysia and Thailand, sharing radar data 10 days after the disappearance.

I'm also learning that a number of SAR aircraft are currently sitting on the ground awaiting overflight clearance from neighbouring countries.