Two powerful jets of water are sprayed onto the fire from a truck parked alongside the airplane.

MOFFETT FIELD, Calif.--The flames were raging, and the cries of people trapped inside the plane were audible, even from well over a hundred feet away.

Yet despite the fire crews wearing heavy-duty proximity suits, blasting water from a pair of hoses, and a collection of fire trucks gathered near the burning fuselage, no one looked particularly worried. No lives were actually at stake.

This was firefighter training at Moffett Field, part of an annual process that the crews from the NASA Ames Fire Department and the nearby Palo Alto and Sunnyvale Fire Departments have to go through in order to be certified to work airplane fires. And while the flames were real enough, this was nothing more than a big, fiery, smoky simulation.

In the past, explained NASA Ames fire chief Steve Kelly, his firefighters would have had to travel to places like Salt Lake City to get their annual certification, a process that meant doling out nearly $100,000 in expenses and which precluded the department's being able to do the training with their own trucks, and on their own turf.

But this year, for the first time, Moffett Field--which is adjacent to NASA's Ames Research Center--is playing host to the Aircraft Rescue Fire Fighting trainer. The ARFF setup is a Federal Aviation Administration-approved mobile trainer brought in by a team from Kellogg Community College in Battle Creek, Mich., where it is based, that travels around the country serving crews that need to take care of their annual certification.

To call it a mobile trainer is a somewhat stale term. In fact, it appears to be a deeply burned-out Beechcraft 1900, complete with scorched engines and wheels, and more than its share of scars, scrapes, and bruises.

Yes, according to ARFF program coordinator Joe Teixeira, the trainer affords fire crews like those from the NASA Ames and the Palo Alto and Sunnyvale departments a chance to work on many of the skills they will need if they ever find themselves having to deal with an actual emergency involving an airplane fire.

Further, the training gives each of these crews the chance to work on putting out an airplane fire with their so-called "mutual aid" departments, meaning fire departments that are in close proximity to each other and which would all be called in to handle a real emergency.

One thousand degrees While fire departments like these have traditionally done this kind of training at facilities that use real jet fuel in their blazes, the ARFF system employs propane, and allows for massive flames that can be extinguished with water--or simply turned off.

If one were to wander by without knowing that, however, it wouldn't seem like any kind of benign moment. Teixeira said the flames on the ground outside the airplane, which are meant to simulate fires burning on jet fuel pooled on the tarmac, can reach temperatures of 900 degrees to 1,000 degrees Fahrenheit.

A huge fire rises off the ground, where propane is sending up jets of flames to simulate jet fuel that would be pooled and burning on the tarmac outside a burning airplane.

At the same time, the fires that are set inside the aircraft, and which the crews must navigate to rescue "passengers," can top out at about 120 degrees. Yet the billowing smoke that looks every bit real, is nothing more than piped in theatrical smoke, Teixeira admitted.

Over the course of several days, the fire crews have been taking turns working through the training, which simulates a number of different kinds of emergencies--single-engine blazes, cabin fires, burning tail engines and wheel brakes, and more, all according to whatever the local training officer wants.

And Teixeira and his team will throw curveballs at the fire crews. For example, he explained, while the first few go-rounds will have the fire personnel rushing in the main cabin door to put out interior blazes, he intended to block the door later in the day and force the crews to figure out another way inside.

It begins At first, all is calm. But then someone walks up to the side of the trainer, opens a hatch, and plugs in the audio system. Suddenly, the sound of screaming emerges from the airplane.

With that, a red Palo Alto fire engine comes hurtling across the Moffett Field tarmac, emergency lights flashing, and out hops a group of firefighters. Yet, despite the developing "disaster" nearby, they don't run, they don't rush. They methodically put on their gear. At this point, the flames are only coming out of the wing engines.

As they hook up fire hoses to their truck, the screams continue. Finally, two firemen in normal fire suits and one in a proximity suit--a special silver-colored suit meant for very hot fires--start blasting water from a hose onto the blaze. Yet, the flames are only getting bigger.

A crew member gets ready to battle the blaze inside and outside the trainer aircraft.

In a real emergency, crews would be using a solution of water and 3 percent special foam known as aqueous film-forming foam designed to help put out jet fuel fires. While the foam is not hazardous, it still must be completely cleaned up after use, and so Kelly, the Ames fire chief, explains that for training sessions like this one, the crews will use only water to extinguish the flames.

Now, two yellow Ames fire trucks have joined the fray, and two more men in proximity suits are helping out. But the flames are now on the roof of the plane, and the crews are now utilizing two hoses and two strong jets of water. At the same time, one of the big yellow fire trucks is blasting two more large jets of water toward the plane.

It's not as simple as just trying to overwhelm the fire with powerful water pressure, though. Kelly explained that because the special foam that's used in real emergencies creates a blanket that can smother a fire, it's essential not to break through that film with jets of water. That's why, Kelly continued, the crews are training on creating a "fog" of water from their hoses that can help put out the fire without puncturing what would be the foam film.

Big savings While Kelly used to have to spend $90,000 or more to send his crews away to do their annual training, he said that bringing in the ARFF system costs just $20,000 and lets the Ames Fire department train with their own trucks and on their own tarmac. And that's key, he suggested, for getting a realistic sense of what it would be like to fight an airplane fire.

And realism is what he's after. He said that in a real airplane fire, it's known that fire can go from the exterior of the fuselage to the interior in just 90 seconds, and so his crews are being trained to attack such a blaze as quickly as possible. That means getting their trucks close to the conflagration and hitting it with "mass application of agent," essentially trying to overpower the fire with as much foam--or water, in this case--as possible in as short a time as possible.

Here, we see the roof of the trainer ablaze.

In fact, he said, the trucks have just about two minutes' worth of agent on board, so it's crucial to try to get the fire out quickly, even as crews are climbing on board to try to rescue anyone stuck inside. If a truck empties out, and the fire continues, its crews must take the time to re-service--meaning loading up a new tank full of agent--and then repeat. It's a "dance" of "fight fire, re-service, fight fire, re-service," Kelly said.

From the earliest days of Moffett Field in the 1930s, when it was a Naval base, there has been a fire department here. First it was run by the Navy, Kelly explained, and then in 1994, when the Navy left, it was run by the California Air National Guard. In 2006, the department was turned over to Wackenhut Services, a private company based in Palm Beach Gardens, Fla.

But you'd never know it to look at Kelly or any of his 50 crew. Their uniforms all identify them as members of the NASA Ames Fire Department, and they protect everything from Moffett Field to the entire NASA Ames Research Center and all the private partners that are based here.

Piercing operation The last exercise is what Teixeira called a "piercing operation," in which a very sharp implement at the end of a crane arm on top of one of the fire trucks is extended over the plane in order to puncture through its top. The idea here is to try to put out an interior fire without breaking too large a hole in what might be a highly-pressurized cabin. That could cause a serious problem.

One by one, crews of two get in the front of the truck and carefully maneuver the piercer into place above an aluminum plate on top of the plane. It's a tricky move, especially for the inexperienced. As Teixeira puts it, not so delicately, you only want to pierce through the roof of the plane by about four or five inches because "if this was a passenger plane, and you went all the way through, you might go through someone's head."

As a crew member named Bobby calls out instructions to his fellow firefighter Sean, Sean says, cautiously, "You're going to spot me, right I've never done this before."

But Sean is spot on, and though it takes him a minute or so, he puts the piercer in exactly the right place. On a monitor showing thermal images, we can see a flame get blasted with water from above. And not long after, we see water pouring out from the plane's windows.

All in all, the training has been a big success, said Ames fire battalion chief Bob Wilson. He explained that he has been very pleased with everyone's performances during the exercises and that the only thing he'd wanted to see corrected was having the crews be quicker to move their trucks and themselves close to the fire.

"Your instinct is not to be close to the fire," Wilson said, "but these vehicles are designed [to get close]. 'No, it's OK to drive two feet close to the flames.'"