Bird Bath (Wired)

Sure, a Jet’s Wings Need Scrubbing, But Its Guts Need a Flush, Too

(link)

Philip Joshua eases his chrome-rimmed Ford crew cab into mid-morning traffic on the tarmac at John F. Kennedy International Airport, keeping pace with a taxiing passenger jet. It doesn’t take much. We’re moving 5 miles per hour, if that, slowing even more for bumps on account of the 40 gallons of hot water in the trailer behind us. Also in tow is a 24-kilowatt generator and a mysterious black cart that could pass for a stadium speaker. Evidently, this setup is Pratt & Whitney’s EcoPower Engine Wash rig, and we’re on our way to bathe the business ends of a 767.

It’s not just for aesthetics: Keeping the compressor, turbine, and fan of a jet engine clean decreases fuel consumption by 0.5 to 1.5 percent — not a shabby X factor given commercial aviation’s projected global fuel bill of $132 billion for 2007. In the old days, airline mechanics simply used a fire hose. But in the ’90s, tighter environmental controls shunted engine washing to special pads in far-off corners of select airports. The process itself took too much time to be cost-effective. That’s where the EcoPower came in. Now, pony up $3,000 per narrow-body engine or $5,000 per wide-body and Pratt & Whitney will bring its closed-loop system to you, scrubbing away the atmospheric gunk and jet fuel residue in less than 90 minutes. So far, 40 airlines have signed up for the service. P&W engineers say that if all commercial aircraft got a regular engine cleaning, the industry would save more than 2billion pounds of fuel and about $836 million each year.

“Obviously you’re familiar with a high-bypass engine, right?” says Anupam Bhargava, the general manager of the EcoPower program, as we poke our heads into the inlet cowling of a General Electric CF6-80C2. I am now. Joshua and his partner, Carlos Arauz — both of whom can tell a GE CF6 engine from a PW4060 by sound, thank you — scurry to set up. They maneuver a round yellow manifold with four nozzles into the cowling, then connect a hose to the tank of hot water. Next they manhandle the cart into place below the exhaust and extend a black rubber tarp from beneath it. The nozzles will shoot a pressurized spray into the engine, scouring the blades of the turbine to a shine. The cart and the tarp will catch the H20 on its way out, keeping the tarmac clean.

Everything ready, Bhargava tosses me a set of ear protectors and reminds me to stay at least 30 feet away (lest my minced guts muck up this soon-to-be-pristine engine). The 767-300 belongs to North American Airlines, which runs a steady salvo of troop transports to Germany and the Middle East. Joshua spins a finger in the air, and the engine spools. The red belly light blinks. Wavy lines of heat emerge from the tail. A mist of water drifts into the black catchment. Sixty seconds later, Joshua slices one hand across his throat and the engine slows.

Arauz leans his upper body into the exhaust and emerges holding a plastic cup filled with black sludge — a heavy-metal cocktail of cadmium, lead, and arsenic. “Frankly, materials you don’t want in your groundwater,” Bhargava says. Joshua takes a sample with a digital probe, then punches the results into a laptop propped on the water tank. Rinse, repeat. By the third cycle, the water in the cup has lost its steely tinge.

In two days this engine will depart for Kuwait, embarking on another year of sucking its way through Arabian dust and the grit of a thousand thousand air miles. It takes Joshua and Arauz 15 minutes to pack up. As we pull away, I spot the only evidence that we’d been there: a fist-sized puddle of purified water.