Blackout vs. Grindor
Blackout. Grindor. They all look the same to me.
Ironhide, "Law and Disorder"
Revenge of the Fallen never explicitly establishes Grindor as a separate character from Blackout. Screenwriter Roberto Orci, when asked, was not sure whether they were supposed to be the same character or not. In the TFWiki.net Hasbro Q&A for July 2009, it was confirmed that Grindor, not Blackout, appears in the movie.
In the novel, his name is never used, just a huge Russian helicopter. Who can blame them, Roberto Orci couldn't remember it either.
Internal files for the Revenge of the Fallen video game identify this character as Blackout, indicating that the game had been developed with the understanding that they were the same character... but had dialogue re-recorded to refer to him as Grindor.
On the cross-sell for "The Fury of Fearswoop" multipack, Grindor is mistakenly given the name Blackout. Still, at least he remained a Decepticon.
In Revenge of the Fallen: The Movie Universe, Blackout is featured instead of Grindor. Guess the writer didn't get the memo in time.
In the Revenge of the Fallen: The Junior Novel, Blackout is the character assisting Megatron and Starscream in the Forest against Optimus rather than Grindor.
The 2-disc special edition of Revenge of the Fallen features some still poses of the Autobots and Decepticons, and names the helicopter as Blackout.