Many airplane crashes have similarities, all are different in their circumstances.
Having said that, an onboard fire may not disable everyone or anyone, initially. However an exploding nose wheel tire can do alot of damage or one that "catches fire" .
The nose wheel tire is located very near what is called the electronic and equipment bay or as some refer, the E and E bay. An exploding tire, or slow burn could theoretically damage critical components knocking out electric power to communication equipment. And or damage other electronic equipment so as to create a high load on other equipment, causing electric busses to start disengaging.
A nose wheel tire can become overheated during the takeoff roll. It happens when a plane is heavily loaded, warm temperatures, long takeoff roll, late rotation, or rotation close to max tire speed. Not really uncommon.
In the scenario many are suspecting, is that smoke began to fill the cockpit. Oxygen masks are on and an immediate turn to the nearest airport is made. The climbing and descending can be because the autopilot has also become disengaged, that would explain why it took so much altitude to recover.
But as the 777 captain says, the oxygen system would have also become disabled or depleted and that is most unlikely. Very rarely to we find what is called dual failures.
The airplane would not necessarily be on fire enough to bring it down immediately. Small, fire, damaging equipment, producing smoke and might even go away if the oxygen source, (high altitude in an unpressurized bay) goes away and or fuel source is not enough to continue the fire.
Plausible but i am not buying it myself. But its the closest to Ocam razor that I have read.
Nobody is suspecting that, you are projecting.............
The burning nose wheel theory has been described as highly unlikely. It has no brake gear to heat up, and is simply a tire on a rim. Even if it was under-inflated during takeoff, the likelihood it started on fire and filled the cockpit with smoke isn't likely. (I've heard two pilots discredit that today.)
All good points, but let's remember they flew to after leveloff, about 40 minutes after takeoff before they dropped off secondary radar.
First, as the captain (caller to Rush) pointed out, wheel fires are almost always brake-related. There are no nose gear brakes.
The 777 is a very sophisticated airplane. The caller could have gone on to say a nose gear fire would have manifested long before level-off. There are tire pressure sensors that would have generated alerts even before a fire might have happened, not only based on minimum or maximum pressures, but on pressure differentials with adjacent tires exceeding a preset value. These sensors would have alerted the crew to a tire in the process of deflation. We know they didn't have a tire failure (catastrophic) on takeoff or they would have returned immediately, or at least after dumping fuel, because the alert system would have told them they had a tire failure. Likewise if there were a nosewheel bearing failure -- the temps would have taken longer to climb but they would've blown the fuse plugs (deflating the nw tires) long before level-off. And lastly the temps at FL350 are very cold. The tires cool as they are exposed to the airstream before retraction, and then they cool again as the jet climbs rapidly to outside temps of around minus 50C at 35k. So the chances of an overheated tire causing problems are attenuated by the low temps in the unpressurized nosewheel well. Additionally, they weren't really very heavy -- they had 50 empty seats and only 8 or so hours of fuel. This is an airplane when fully fueled can go about 14 hours, so this was not a heavyweight takeoff, and it was at night when the temps are lower.
I think the nosewheel fire scenario is highly improbable.