NARRATOR: The frame for the single massive delta wing, the heart of the Boeing design, is already in the works. But the skin that will cover it is being cooked up over a thousand miles away at Boeing's headquarters in Seattle.Engineer George Bible has spent the last year experimenting with a revolutionary material for the surface of the wings. It's a resin and carbon fiber mix called "thermoplastic." In small quantities, it's been used on fighters before, but no one has ever tried to create anything as large as a 30-foot wing skin.GEORGE BIBLE (Manufacturing Engineer, The Boeing Company): It's very challenging. We have no time or schedule to design something else, so we, we have to make it work the first shot.NARRATOR: Thermoplastic wings will be lighter and more durable than conventional wings. There may even be other undiscovered benefits, according to another engineer who first experimented with the material in the '80s, Frank Statkus.FRANK STATKUS: I personally would love to have thermoplastics on this airplane, because I know that there's value in the future. Even though I can't tell you in all the areas where we might find that value, I do know it's there.NARRATOR: The future in a word: thermoplastics.But right now, George Bible needs to solve some pressing problems. Making thermoplastic begins with these sheets of graphite, also known as carbon fiber, the same lightweight material used in fishing rods and tennis rackets. For the wing, it's laid down up to 90 layers deep on top of a giant metal mold or tool.GEORGE BIBLE:\tWe take layers of these graphite fibers and set them on top of each other, and then we put the resin in between to hold them together.NARRATOR: After three weeks of lay-up, the wing skin is tightly wrapped in protective bags, ready for the next step, a massive oven called the autoclave. The huge chamber acts like a pressure cooker.GEORGE BIBLE: The autoclave, for me, is always the most stressful part. You have nightmares at night thinking about all of the terrible things your autoclave could do to it.NARRATOR: First, all oxygen will be removed to prevent a cataclysmic explosion. Then, with the wing heated to the melting point of lead, nitrogen will be pumped in, raising the pressure and exerting tons of force upon the thermoplastic, forcing the fibers to blend with the resin. In short, this is literally hell on earth.For the next 30 hours, George Bible will hold his breath, until the cooked skin from the autoclave and a perfectly formed wing skin is revealed.GEORGE BIBLE:\tOh, she looks beautiful doesn't she? Looks good, looks very good.NARRATOR: But this skin is only the first. Boeing will need three more, one for each side of its two delta-winged X-planes. And although Bible is elated at his success, he knows that the next skin, for the lower wing, will be far trickier. It involves a more complex curved shape.And, in fact, when the next skin emerges from the autoclave, the first signs are ominous. Creases and folds on the surface hint at hidden structural flaws.GEORGE BIBLE:\tMan, that does not look good, those wrinkles. I'm afraid we're dead in the water.NARRATOR: An instrument scans the surface of the panel using water and sound waves to probe for air pockets that could fatally weaken the wing.GEORGE BIBLE:\tWhen we have a gap in the plies, the sound will not transmit through there well.NARRATOR: George Bible's worst fears are confirmed. The skin is riddled with defects.GEORGE BIBLE:\tRight now I'm just, just exhausted. We can't get a break, I mean it's just downhill. So we'll have to do what we have to do to get a panel down to Palmdale as fast as we can.NARRATOR: After hundreds of hours of work, the wing skin is worthless. With the first wing frame nearing completion down in Palmdale, Bible's team and its bold experiment are simply running out of time.