I have no idea about the techniques, policies or equipment, but watching a Major Foam Unit [as we called them] squirting foam at the left engine [that didn't exist] and not even moving close enough to achieve the necessary trajectory was …. interesting.
We agree about at least one thing ... I have no idea about air crash firefighting either.
Perhaps they saw fuel pouring from the attachment point of the missing engine? Possibly they were responding in accordance with their training? Maybe there were some good reasons why the responded as they did?
The function of the foam is primarily to starve the fire of oxygen. How effective it is to stream the foam from a distant nozzle, when fire has burned a hole through the roof, I don't know.
Some airport fire departments have special trucks for attacking fires inside the fuselage. The trucks have purpose-designed nozzles on long-reach arms, able to puncture the aircraft skin, and disperse the foam in a volume-filling mist designed to suppress flame and reduce temperatures with great rapidity. Were the fire crew you found so interesting taking care of the area around the plane, while waiting for other equipment to handle the interior?
I don't really know ... but it would be great to hear from somebody who does.
In a similar vein, I've read several posts excoriating the flight crew for their delay in authorizing emergency evacuation. It seems plausible, at least, that they were physically and then psychologically stunned after their ship came to rest -- the nose may have experienced some of the largest sustained accelerations as the plane pirouetted on the runway.
After taking a few moments to recover themselves, they would presumably need to pull up their pre-evacuation checklist, and run through it. As more than one person has observed, evacuating passengers in the proximity of gigantic 100,000 lb thrust-class turbofans could have resulted in dreadful casualties, without assurance that the engines were stopped (or in fact, detached). With the ship badly damaged and an engine missing, the engine indications were presumably different from what the crew is used to. Mightn't they have wanted to take a bit of time to make sense of what they were seeing, and to confirm that the engines were stopped?
I'd be interested to hear from experienced air carrier pilots here how long they expect it would take them to complete their corresponding checklists in such a scenario.
Maybe the Asiana crew took an unconscionably long time to OK evacuation. Or maybe they were doing reasonably under the circumstances. What do the veteran airline pilots say?