In the Voyager episode: "Future's End, Part II" Chakotay and B'Elanna crash land on earth.
CHAKOTAY: Propulsion is offline. Voyager, we're going down
Later in the episode they get rescued by the doctor and have the shuttle working immediately. They proceed to blow up the truck that they think has the time machine in it.
One would think that the crash itself would add additional damage to what they had incurred already.
After they were rescued by the doctor they had almost no time to get to Paris and Tuvok.
It does state in the episode:
EMH: Tuvok's at the shuttle. He's starting repairs.
How were they able to get the ship working again so quickly? They had no spare parts with them and had to get it working immediately. If they could get it working so quickly, why not do it before they crashed?