As we’ve noted before, “green” business articles are tempting for journalists right now. That is doubly so when the story involves a Boeing 747 and a rogue billionaire who wants to save the world. So it was no wonder that the press went wild when Richard Branson’s Virgin Airways made the first commercial airplane flight powered partly by biofuels. But some reporters had trouble untangling publicity from progress.

Some of the earliest headlines made it seem like Branson had solved the riddle of fossil-fuel dependence for flight: “Virgin Flies Biofuel Jet From London” (AP), “Biofuel Takes Flight with Virgin Atlantic” (CNet), “Historic biofuel flight in Britain” (UPI). Many of the earliest reports sounded like rewritten PR babble, which glossed over the details what the airline actually accomplished. The AP article was the vaguest vignette of boosterism:

The world’s first commercial flight powered by biofuel has taken off from Heathrow Airport.

The goal of Sunday’s Virgin Atlantic jumbo jet test flight from London to the Netherlands is to show that biofuels can produce less carbon dioxide than normal jet fuels.

Before it took off, Sir Richard Branson, Virgin Atlantic’s president, said the breakthrough would help Virgin Atlantic to fly planes using clean fuel sooner than expected.

Sounds great, but it’s a bit inflated. After all, only one of four engines in the plane carried the 20 percent biofuel mix, making it a mere 5 percent of the plane’s total fuel load. As for the remaining 95 percent? Regular ol’ jet fuel.

A few of the early articles, which ran last weekend, like a piece on by Tracy Alloway, mention that only one of the four engines in the plane was supplied with the biofuel mix, but buried the information deep in the story. Others, such as The International Herald Tribune-which published a Frankensteinian article pieced together from three wire articles-mentioned that only one engine carried the biofuel mix, but failed to tell readers how many engines a 747 has.

There are a few things to glean from these examples (like the risks associated with cutting together bits and pieces of wire stories), but the most important is that reporters need to be explicit in covering the details of big publicity drives like Virgin’s biofuel airplane. Furthermore, it is not enough to say that one of four engines ran on a 20 percent biofuel mix-readers are not going to stop and make the calculation that 20 percent of one engine is only 5 percent of the flight’s total fuel. Fortunately, some outlets did the math, including Time magazine, which published a noteworthy piece by Laura Blue, “Can Airplanes Fly on Biofuel?” The headline, phrased as a question rather than an assertion, is more responsible than those cited above, and the article’s nut graph couldn’t be more direct:

As it happens, Virgin’s eco-plane ran only one engine on the experimental fuel; the other three burned standard jet fuel. And the biofuel-powered engine was using a blend of conventional jet fuel and biofuel: 80/20 in favor of the regular stuff. In total, then, just 5 percent of the 49,000-lb (22,000 kg) fuel load consisted of the novelty: a special mix of coconut oil and oil from the Brazilian babassu plant, prepared by Seattle-based Imperium Renewables over the last 18 months and tested by General Electric Aviation in Ohio.

A short clip in The Times (UK) online also got it right:

The 350-seat Virgin Atlantic Boeing 747 flew from Heathrow to Amsterdam with five people on board. However, only 5 percent of the fuel used was biofuels … Dave Daggett, Boeing’s project manager for alternative fuels, said biofuel was unlikely to be certified for passenger service before 2013.

As Daggett suggests, there is confusion about what exactly Virgin’s test flight actually proves considering that, as ABC News’s Nick Watt reported, the biofuel was derived from “150,000 coconuts and babassu nuts picked in the Amazon rainforest.” Branson used the “nutty” oil because he says it wouldn’t compete with food production like corn-ethanol does, but he also said that any mainstream use of biofuels in flight would use algae-derived fuel. That leaves open the question of what the airline industry, and the public, are supposed to have learned from Virgin’s test flight. When will it be possible to enrich the biofuels mix, which blend will deliver optimum efficiency, and what will that fuel be?

Russ Juskalian is a contributor to The Observatory and a freelance writer.