UPDATED 6:45 p.m.: Added NASA’s comment

UPDATED 8:00 p.m.: Added Google’s comment

A company controlled by Google’s top executives, including its billionaire founders, Larry Page and Sergey Brin, appears to have added a new plane to its well-equipped fleet: a fighter jet, or more precisely a Dornier Alpha Jet. According to Wikipedia, the Alpha Jet is a a light attack jet and advanced trainer aircraft manufactured by Dornier of Germany and Dassault-Breguet of France.

The last time we checked on H211 L.L.C., the company that operates the private jets owned and used by Mr. Page, Mr. Brin and the chief executive, Eric Schmidt, was in October 2007. The company had just added a Boeing 757 to a fleet that already included a refurbished Boeing 767 and two Gulfstream V’s. All four planes had landing rights at Moffett Field, the NASA operated airfield that is a stone’s throw from the Google campus.

On Thursday, The Mountain View Voice reported the existence of the fighter jet, which it said had been spotted at Moffett Field. Federal aviation records confirm that H211 L.L.C. has registered a Dornier Alpha Jet made in 1982.

Google, which does not own any of the airplanes and has no relationship with H211 LLC, said that like the other planes, the Alpha Jet is being outfitted with scientific instruments for NASA missions, including instruments that the other planes could not carry. “Because of the type of aircraft we are talking about, NASA now has the ability to do even more than they could before,” said Matt Furman, a Google spokesman.

Ken Ambrose, a vice president of H211 L.L.C., could not be reached for comment.

After The New York Times filed a Freedom of Information Act request with NASA, the agency released documents related to the lease agreement between NASA and H211 LLC. In an e-mail message Thursday, Dolores Beasley, a NASA spokeswoman, said: “The agreement was amended to support a recent science mission — observation of the re-entry of the European Space Agency’s ‘Jules Verne’ Automated Transfer Vehicle (ATV). Additional amendments are in progress in regards to the Alpha jet.”

It is not clear who exactly owns or flies the fighter jet. Mr. Schmidt is an avid pilot.

If the top Googlers indeed own the fighter jet, they would not be the first Silicon Valley moguls with such luxury toys. Oracle’s chief executive, Larry Ellison, has owned several aircraft, including fighter jets.

Presumably no attacks on Microsoft are planned at this time.

See a follow-up post on what NASA has to say about its plans for the jet.