Trial by Fire

The Howe brothers' crew builds an all-terrain wheelchair for a veteran.

The Howes take on building and testing a prop vehicle for a major motion picture. Meanwhile the crew moves forward on the Riptide amphibious vehicle, including a dangerous test of its escape hatch system underwater.

Time is ticking on the Riptide project. The Howe & Howe team bears down, but their first test with the Riptide is disasterous. But it's not all bad news. Mike's seemingly tangent project -- a turret for the Riptide -- is an explosive success.

It’s the 11th hour for the Howe & Howe team, one week before they present the amphibious Riptide to the Army. With a key member in the hospital, the team will have to scramble more than ever to fix what caused catastrophic engine failure.

Primitive survival expert Matt Graham demonstrates how to build an atlatl, a device used to throw spears and darts faster and further.

Primitive survival expert Matt Graham demonstrates how to build a fire.

Survival expert Matt Graham demonstrates how to purify drinking water.

Primitive survival expert Matt Graham builds a lookout from a small tree.

Primitive survival expert Matt Graham demonstrates how to fell a tree.

Primitive survival expert Matt Graham demonstrates how to build a smoker.

Primitive survival expert Matt Graham demonstrates how to build a shelter.

Primitive survival expert Matt Graham makes a bucket out of tree bark.

Primitive survival expert Matt Graham demonstrates how to make a bow drill.

Primitive survival expert Matt Graham demonstrates how to make a blowgun.

Rescuing stranded climbers with no coordinates is a daunting task.

Jason preps his helicopter for the world's highest landing spot.