We're taking bets in the Flightglobal office after seeing this article in the New York Times. I've got my money on 18-24 months.

U.S. Aides Believe China Examined Stealth Copter

By MARK MAZZETTI

[Key excerpt:]

American spy agencies have concluded that it is likely that Chinese engineers -- at the invitation of Pakistani intelligence operatives -- took detailed photographs of the severed tail of the Black Hawk helicopter equipped with classified technology designed to elude radar, the officials said. The members of the Navy Seals team who conducted the raid had tried to destroy the helicopter after it crashed at Bin Laden's compound in Abbottabad, but the tail section of the aircraft remained largely intact.