Burdokva said:
I've always though that the Falcon's flight trajectory was preset. After all, the technicians messed up its hyper-drive, maybe it was programmed to fly towards the Executor? Yes, it does have the plot-hole that they went to get Luke first, but still..
Also, I'm not sure how it is explained in the EU, but can a ship's tractor beam hold on to another ship, if the latter engages its hyper-drive engine? Maybe Lando and Chewie didn't care about the tractor beams (and thus flying towards the Executor), as long as they got the hyper-drive working.
Ah, missed the EU question! Tractor beams in SW have never been highly defined in a way that it's commonly used all to often. This tells me that they are relatively weak in that respect and I imagine multiple beams should be used in conjunction to target a maneuverable ship like the Falcon. The times I've run across tractor beam references in the EU are when they are used to guide in ship, tow a ship, or when they've are either targeting a slow moving ship OR the ship has already been mostly disabled.
In the original Zahn Trilogy, Grand Admiral Thrawn uses cloaked asteroids being deployed by tractor beams around Coruscant to literally blockade the planet by using invisible rocks preventing traffic from going into and out of it's dual over-lapping shields. Sensors indicated that the tractor beams were used over 200 times but only about dozen cloaked asteroids were actually deployed. This means that the tractor beams in SW like shields are invisible and so if the Imp tech on the Executor were trying to get get a lock we couldn't see it. Thrawn also almost capture Luke in his X-wing in space using a tractor beam but Luke managed to launched and unpropelled proton torpedo that the tractor beam locked onto instead of his fighter as he thrashed his sublight engines by reversing thrust and then making a jump to lightspeed but soon broke down (because of said thrashing of engines but he did escape!)
In TIE Fighter the game, the most advance of Imperial craft, the TIE Defender employs a tractor beam to immobilize opposing vessels. However, enemy ships with enough momentum and speed (and pilots with enough cunning) can break the lock against the Defender's tractor beam and this must be constantly done in a line of sight. A ship that is caught in a tractor lock can not jump to hyperspace as it would be the equivalent of being in a gravity well.
In that escape from Bespin there were four TIEs on the Falcon's tail boxing the ship in and leading it toward the Executor. However, the pilots skills in conjunction with the Falcon speed would make it incredibly hard to get a lock on.
Happy Star Wars Day! May the Forth be with us! =D