Could have been a deleted scene from Spinal Tap:

It was at this time that Jizzy performed his legendary publicity stunt to try and help album sales. This involved Jizzy, with the help of a few others, successfully erecting a cross on the letter ‘Y’ of the Hollywood Sign and performing a mock crucification on it, with a camera crew in a helicopter to film it. The band had assumed the authorities would quickly notice the stunt, but Jizzy was stuck on the cross, 60ft in the air, for several hours. Eventually a TV news helicopter spotted him and the police and fire dept were called to bring him down. [from Wikipedia’s entry on the 1990s band Love/Hate]