Very Light and Fast

Mechanical Engineering, Jan 2007 by Brown, Alan S

Developments in materials, production methods, and turbine design have spawned a new class of business jet.

At least one aircraft maker had a lot to be thankful for this past Thanksgiving. The day before the holiday, the Federal Aviation Administration awarded Cessna Aircraft Co. a certificate to begin production of the new Citation Mustang jet. When it rolled its first Mustang out of the hangar at Independence, Kan., later that day, its first customer, Kent Scott, president of Scott Aviation of Fresno, Calif., was waiting on the tarmac to take possession.

The Mustang is Cessna's entry in an entirely new class of aircraft, the very light jet, or VLJ. How light? At 6,500 pounds unfueled, the six-seat Mustang weighs less than many sport utility vehicles. Its twin Pratt & Whitney turbofan engines weigh so little, about 275 pounds each, you could walk into any gym and find a dozen men and women who could bench press one of them. Some might even be able to bench press both at the same time.

Yet the Citation Mustang and other VLJs now nearing commercialization are real jets. Each of the Mustang's PW615F engines generates 1,460 pounds of thrust, enough to reach a top speed of 390 miles per hour. It cruises above the weather at 41,000 feet and can fly more than 1,300 miles-nearly halfway across the United States-without refueling.

The Mustang made it out the door just before the Eclipse 500 from Eclipse Aviation in Albuquerque, N.M. The six-seat Eclipse is even lighter than the Mustang. Empty, it weighs in at 3,550 pounds, or about as much as a Toyota Avalon. Although its twin PW610F turbofans produce only 900 pounds of thrust, the Eclipse cruises at 425 miles per hour with a range of 1,300 miles.

Still more very light jets are on the way, including the Adam A700, Embraer Phenom 100, Diamond D-Jet, Piper Piperjet, and Honda Hondajet. None of them is cheap. The Mustang sells for about $2.5 million, the Eclipse for $1.5 million. The D-Jet costs slightly less than the Eclipse; the Hondajet is more than $3.6 million. Yet with traditional business jets heading north from $6 million, the very lights are generally bargains at the price.

boom time

Why the sudden interest in cheap jets? There are really two answers to the question, one economic and the other technical. The first has to do with the changing nature of business travel.

"This has been going on for quite some time," said Dan Breitman, vice president of Mississauga operations and turbofan development for Pratt & Whitney Canada Corp., which makes the company's small engines. "I do a lot of traveling myself, and even before 9/11 it was becoming more difficult. It is a 4 ½-hour drive from Toronto to Detroit. If I want to fly, with getting to the airport early and security checks, the time is the same. For that type of distance, it is very time-consuming."

Breitman would waste even more time if he wanted to go to a smaller community. "Today in North America, there are about 30 big airports that you have to go through," he said. "If I want to go to some small town in Texas, I have to go through Atlanta or Chicago and then change planes. These new VLJs can hit about 5,000 airports," Breitman said. "When you take a five- or six-hour trip and shave that to three hours, or turn a two-day trip into a one-day, you're really adding value. This is what VLJs are going to do. They're going to change the way people think about travel."

Breitman and others envision a world where small corporate jets ferry executives around the country. Smaller companies could even buy a share in a jet through one of the industry's many fractional ownership plans (think time shares for airplanes). Analysts and marketers imagine air taxi services going between smaller cities and communities.

Optimism is running high. Several startups, such as Dayjet, Linear Air, and Pogo, have jumped into the air taxi business. Eclipse claims 2,500 orders for its new 500.

There are skeptics, of course. One of them is Richard Aboulafia of aerospace consultant Teal Group Corp. in Fairfax, Va. "The FAA will not let you offer a service with a single pilot," he said. "Even if it did, you would have to pay the pilot hundreds of dollars per day. You'd have all the costs associated with a larger aircraft, but you'd be amortizing them with the handful of people in the cabin rather than 200 passengers in the back. That means you have to provide a first-class service and find people willing to pay for it on 600- to 1,000-mile trips."

Concerning claims of enthusiastic orders, he said, "Nobody's order book in this industry is transparent." Aboulafia said that several firms with supposedly fat order books failed to take flight.

Still, Eclipse is set up to manufacture four planes per day. Given a five-day work week, that's 1,000 jets per year. "World War II was the last time anybody produced that many airplanes in a day," said the company's vice president of engineering, Ken Harness. He said Eclipse hopes to expand to six jets per day, or 1,500 per year.