I don't think so. He wanted to 'blow the whistle' on the CIA in UFO coverups. He did not actually see a UFO himself.

Timothy Good has: Performed in "Lucky Colour Blue" in 1975. Played himself in "UFO: Down to Earth" in 1997. Played Himself - UFO Researcher in "Breakfast" in 2000. Played Himself - Author, Above Top Secret in "UFO Invasion at Rendlesham" in 2003. Played Himself - Author: Beyond Top Secret in "The British UFO Files" in 2004. Played Himself - Special Guest in "On the Edge" in 2008. Played CIA Ops Officer in "Innocence Lost" in 2010. Played CIA Ops Officer in "Fair Is Fair" in 2011.

O star of beauty, oh spacecraft bright, Above Eyes Only- is they insight! sorry this stuff is all rated Above Eyes Only!

By providing materiel and even some pilots (via the CIA).

Despite the many stories, there is no UFO in normal gameplay on GTA San Andreas. There may be a mod available, to download via a computer. You would need to check on the internet for that - suggest you try gtawiki