Star Trek: 10 Starfleet Decisions With The Most Devastating Consequences
7. Sending Ships Out Of Spacedock Before Completion
Captain Kirk, Captain Scott, and Commander Chekov were present aboard the USS Enterprise-B on her maiden voyage. Thus, they were present when the Excelsior-class ship received the distress call from the SS Lakul and the SS Robert Fox. Naturally, Kirk's first instinct was to jet to the rescue. Captain Harriman, freshly out of the box and squeaking like an unused toy, jovially told the seasoned officer that the ship simply wasn't ready. That quickly meant nothing as it turned out that the Enterprise was the only ship in range.
So, away they went, arriving at the site of the Nexus. There, they found the two transport vessels trapped in the energy ribbon's trailing edge, unable to escape. Here, the true trouble began. The Enterprise was unable to simply tractor them out, as the beam hadn't been installed yet. There was no medical staff aboard, nor were there any photon torpedos, the latter of which would have allowed Scotty to detonate and anti-matter explosion around the ships, freeing them.
Never leave Spacedock before Tuesday, which is apparently the only day for installs in Star Trek.
These deficiencies led to the perceived death of the greatest captain that Starfleet had, in the 23rd century at least. Captain Kirk was lost in action, leaving the Enterprise-B with an ugly stain on its memory.