Boeing C-40 Clipper
A C-40 Clipper, similar to the VIP jet than often transports Treasury Secretary Tim Geithner US Air Force

The news made a minor splash on Twitter among professional Washington watchers and within a circle of equally wonky, detail-obsessed people: aviation geeks. Tim Geithner had been spotted in coach class on a domestic flight. Specifically, the Treasury Secretary had been seen on a flight from DC to Los Angeles, on the way to a conference, according to a story on Wednesday in Los Angeles local blog LA Observed.

A man who oversees $2.6 trillion in federal revenues traveling the same way middle-class families do, squished in at the back of the plane? It turns out that, according to a Treasury official, Geithner actually flies commercial within the U.S. all the time. On the flight to LA he was in fact in premium economy, a class between first and coach offering more legroom, but still with no free drinks or meals -- at least according to a tweet by Politico's Ben White.

Is making Geithner fly coach the Obama administration's way of letting people know that it does not waste money on luxuries? That is not the case. The policy detailing travel restrictions for Treasury officials is a product of the Bush administration, as this document dated 2008 shows. "First-class travel shall not be authorized unless coach-class or business-class is not reasonably available," says the directive in question.

But on international trips, the kind where Geithner goes to summits at which leaders frantically try to save the ailing eurozone, it's a different story. Nobody can really imagine Geithner squeezing into seat 59L for the long overnight flight to Frankfurt, with a screaming baby in the row behind and a nosy "tourist", who may or may not work for a foreign country, peering from the next seat at the stack of classified documents the secretary is trying to read. Of course not. That does not happen.

A domestic four-hour flight from DC to Los Angeles is one thing, overseas long-range travel is another. And for those trips, often multi-nation jaunts over several days, Geithner travels like other top government officials: on a government jet. Typically the Treasury secretary flies on a Boeing C-40 Clipper, an Air Force version of the popular 737 jetliner, seating just a few dozen and with the range to cross the Atlantic nonstop from Andrews Air Force Base, just outside DC.

But compared to the luxurious private jets of business moguls and Arab sheiks, even the Clipper's interior is a workaday affair. Built for comfortable efficiency, it has a few dozen business-class style seats, and a private compartment with desk and bed for the secretary to work, sleep and arrive rested at meetings. And of course it has secure communication gear and satellite links to allow crew and passengers to talk, if need be, to Washington -- something that could not be done on a commercial jet.

And some countries don't even have VIP jets for their top officials. They're not small countries, either: one is Great Britain, where the prime minister and the Queen herself use leased airplanes, generally from British Airways, for their international displacements. But that's not necessarily cheap: leasing an entire passenger jet and crew, for days, costs hundreds of thousands of dollars. Which proves that, when government officials and their entourages have to travel, going commercial doesn't necessarily save taxpayers money. But sometimes public relations are all about good visuals, and the sight of a cabinet minister in a coach-class seat is guaranteed to buy some goodwill -- and, why not, garner a few extra votes from the minister's surprised seatmates.