His statement accurately describes turbofans as well, since the power to turn the fan comes from the core section.
Okay, from this it seems that the relevant scene in the movie may well have been purely Hollywood. On the other hand, if you do happen to see the movie in question soon you should be able to recognize the scene I’m talking about and maybe it will make more sense than the script.
All this said, the technical details are much less than gaping holes and loose ends in the plot, and even those are to the side of the true point of the movie: muthafuckin’ snakes on a muthafuckin’ plane.
You missed a nuance point.
I said that most of the output airflow from the high pressure compressor gets routed into the combustor, minus a little for internal cooling & whatever high pressure bleeds there may be. That’s absolutely true of both turbojet & turbofan engines.
To clarify further, compression is a multi-stage process (anywhere from 9 to 18 in modern engines) and the further upstream / forward you go in the engine, the cooler & less compressd the air is. A typical installation will have 2, 3, or even 4 bleed taps at various stages to get the correct pressure/temperature/volume mixtures needed for various purposes.
Finally, as you point out, way up at the front is a special stage called the fan. This is the fundamental distinction between a turbojet & turbofan, as you point out.
The fan section is almost universally just a single layer of blades, although I believe there were some 2-stage fan designs tried over the years. In any case, the fan processes a very large volume of air at a very low pressure increment. And a large fraction of that air is ducted around the rest of the engine and never enters the compression / bleed / combustion process. For a fighter turbofan, maybe only 30% of the air goes around the engine & 70% goes into the compressor/combustor. For a late model airliner, it may be more like 90% bypasses the engine & 10% goes through the compresor/combustor.
So you’re correct in saying that of all the air which enters the front of a modern engine, most bypasses the combustor. Meanwhile, I’m also correct in saying that of all of the air which enters/exits the compressor, all of it is burned except for that small fraction which is bled off for ship’s services.
In many ways, the fan is really just a very fancy propeller bolted on to the front of the engine & wrapped inside the cowling. It provides a lot of thrust by moving lots of volume of air at low velocity / pressure increment. Which is pretty much the operating definition of a prop.
Said another way, the engineers realized that there was a lot of residual wasted energy in the fast hot air coming out the tail pipe of a traditional turbojet. The fan drive assembly is a way to extract extra rotary horsepower from that wasted heat & velocity. And all that extra rotary horsepower is then coupled to drive the fan and convert it into usable thrust. Some early designs had the fan at the rear to simplify the engine’s mechanical design. Then somebody noticed that if they put it at the front, they could use it as an extra low-gain first stage of compression, and the now-typical turbofan design was born.
In a truly late-model engine design (last 10 years), in fact the vast majority of the total power / thrust comes from the fan. I suspect that eventually we’ll get to the point where almost all the heat & velocity of the turbojet core will be somehow siphoned off before it gets to the freestream, and the engine will seem to outsiders almost like a big fan powered by an electric motor that makes no obvious heat.
I checked with my friend who used to fly 747s for Tower Air. Not surprisingly he confirms most of what LSLGuy has posted. Here are some highlights:
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There are a total of 6 possible sources of electrical power; thus, “the chances of total avionics failure was slim indeed absent some fantastic lightning strike or catastrophic fire.” The final backup was to switch to batteries, which could provide 38 minutes of uninterrupted avionics.
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In the models he flew, both crew and passenger oxygen was from high-pressure bottles.
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Pressurizaion comes from turbine bleed air, which is then run through one of three Air cycle machines (ACMs) to cool it to the desired temperature.
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The cabin isn’t airtight - the door seals leak some and two bleed valves control cabin pressure. With the ACMs turned off and the bleed valves closed, the cabin will lose pressure (effectively, gain altitude) at a rate of 500 to 1000’ per minute, mostly depending on how new the door seals are.
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It isn’t possible to open any door of a pressurized plane (basically, the pressure pushes it closed). WOW (weight on wheels) during landing will automatically fully open bleed valves so that doors can be opened in case of the need for emergency evacuation.
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The 747 can fly on 2 engines - even 2 on the same side. My friend has done several 3-engine ferry flights, including one from Frankfurt to New York. The 3-engine takeoff is a concern because of the possibility of having to deal with a failure of the “wrong” engine and thus “2 on one side” during climbout. This can be handled, but he reports that the procedure (which he has flown a bunch of times in a simulator) is “very sporty”.
Can’t say that I’ve ever heard “helm” used in this context - in my experience it would be “taking the controls” or “taking control.”
Maybe Mr. Sulu is the co-pilot? 
Okay, I admit I’m not an expert in the terminology, and I’m using the sense of “helm” generalized from the nautical sense – direct control of a situation – so “manually” may have been a bit redundant.
You are indeed correct, and thank you for expanding on that point in such a polite way. When you said “Air comes into the engine face at ambient temperature … The first part of the engine compresses the air to 15-30 atmospheres of pressure …” I misunderstood your reference - this does not describe the fan, but the compressor. Thanks.