"There was a big explosion, and we lost all visibility," he recalls. "Some roadside debris even landed in the vehicle."
But the troops emerged unscathed, and kept on driving – something unthinkable a few years ago. Captain Burnett and his men survived thanks to the MRAP, a new armored vehicle capable of withstanding very large blasts.
The vehicle is one of many innovations the United States military has developed to stay ahead of the insurgents, who readily adapt to American technology. New gadgets and techniques like the MRAP are also crucial to counter the soaring troop casualty rate in Afghanistan.
New methods reduce IEDs' effectiveness
IEDs have become the weapon of choice for insurgents, who generally don't stand a chance against foreign troops in conventional warfare. Crudely made and easy to install – packed under the roadside or stuffed in culverts, and detonated with trip wires or pressure-plates – they have dramatically transformed the Iraq and Afghanistan wars.
In 2008, the rebels used a record 3,276 IEDs, a 45 percent jump from the year before, according to figures from the Joint IED Defeat Organization, a Pentagon agency tasked with stopping the attacks. Roadside bombs killed a record 175 foreign troops, nearly 60 percent of the total.
This year, troop casualty numbers continue to increase. Through April, 69 percent more soldiers were killed than during the same period last year. And military officials predict that IED activity will increase another 50 percent this year.
In an effort to reverse these trends, US forces created Joint Task Force Paladin, headquartered at Bagram Airforce Base. Paladin, formed two years ago, is responsible for coordinating the collection of intelligence and training about the IED threat. It also facilitates the introduction of new technology, such as the MRAP.
"It's a synchronized effort, where we manage the IED threat across the theater," explains Col. Jeffrey Jarkowsky, the commander of Paladin. Thanks to such efforts, the effectiveness of IEDs (measured by the ratio of IEDs used to casualties induced) has decreased by 20 percent from 2008 to 2009, according to Colonel Jarkowsky.
A V-shaped hull to divert bombs' force
The Task Force coordinates training for troops to detect IEDs, which Jarkowsky says is often the most effective means of protection. With detailed training both back home and here in theater, many troops have become experts at spotting the devices.
On a typical vehicle patrol through Wardak Province, just south of Kabul, for example, a reconnaissance convoy snakes along the highway, checking every culvert and ditch. Meanwhile, soldiers riding in MRAPs behind the reconnaissance team scan the roadside for any sign of irregularity.
"Watch the dirt pile on the right," cautions one soldier into the radio.
"Roger, dirt pile on the left ... clear," comes the voice, cackling through the speaker. Later, the soldier speaks again: "Old IED hole on the left."
"Roger, old IED hole, left side ... is clear." This continues for some hours, until the team has canvassed every part of the road. On this trip, they did not find any IEDs, but the troops uncovered one the very next day.
Next to training and visual detection, technology is the biggest boon to serving troops. US forces use a slew of technological gadgetry to counter insurgent threats, according to Jarkowsky.
Some Humvees are equipped with radars that can detect mines buried under the road's surface. Most units have the ability to jam radio signals, which are useful in countering radio-controlled explosive devices. Some units also use drones, manned and unmanned, to look for locals planting a bomb.
But the most effective innovation might be the MRAP. Introduced nearly two years ago, the heavily armored vehicle has steadily undergone upgrades and been so successful that now most patrols are conducted in it.
The latest model, a lumbering behemoth, is being test-run here in Wardak. So far, it has passed with flying colors, according to Chief Warrant Officer 2 Ronnie Thomas, a technician with the 10th Mountain Division here in Wardak who works on the MRAPs.
"It's been a great asset," he says. "Thus far, every IED they have encountered they have withstood." Since the battalions from the division arrived in Wardak in late January, troops have encountered seven IEDs. None of these have killed the occupants, who were all in MRAPs, even though typically roadside bombs have caused serious injury or death in 20 to 60 percent of the encounters. In four cases, the MRAP was even able to remain in commission after some repairs.
The secret is a V-shaped hull, like that of a boat, which allows the vehicle to divert the force of the blast. It's also heavily armored, and the combination enables it to withstand substantial charges.
'Yellow Jacket' drones to go where MRAPs can't
But this all comes with a price – the massive machine moves awkwardly and is ill-suited for Afghanistan's rugged, convoluted terrain. In many cases conditions are so difficult – such as narrow, unpaved roads – that the vehicle cannot be used at all.
The get around this, military planners at the Pentagon are procuring bids for a lighter, more agile MRAP, one they hope can keep up with insurgents.
Other fancy technology might also be on its way.
According to Jarkowsky, the Army is looking to implement a new type of unmanned aerial drone, sporting an infrared sensor, which can catch insurgents in the act, even in the dead of the night.
The Army is also looking into other unmanned aircraft that function like robotic birds, chasing down insurgents even as they run and hide. It might be a few years before the project, called Yellow Jacket, is introduced in theater, Jarkowsky says.
The innovations are necessary because the insurgents are adapting their techniques as well. They have started using larger charges, and even the MRAP has a threshold. In other cases, the rebels have taken to detonating multiple IEDs or combining them with rockets and other weapons.
But still, with further innovations, Jarkowsky hopes to stay one step ahead of the rebels.
"In April, thanks to our efforts, there's a 29 percent decrease in the number of casualties caused by IEDs" from the previous month, he says.
"I won't stop until we get to zero casualties. It won't ever happen, but that's our goal."