A flight plan was a pre-determined course of action or flight path a starship or squadron would take during a specific flight or mission. Flight plans could be entered into a starship's auto-navigation system to assist with helm operations. (VOY: "Nightingale") A flight plan was typically filed with a space station or area of departure prior to take off – for example, shuttlecraft leaving the shuttlebay of a starship were to file a flight plan with the ship before departing. (TNG: "Suspicions")
Traveling without a flight plan[]
In the 23rd century, failing to file a flight plan was a chargeable offense according to Starfleet. In 2266, one of the many charge Captain Kirk named against Harcourt Mudd was galactic travel without a flight plan. (TOS: "Mudd's Women")
Erin and Magnus Hansen, scientists and parents of Annika Hansen, distanced themselves from Starfleet and the Federation and refused to file a flight plan before they left the Alpha Quadrant for the Delta Quadrant in the 2350s and were never heard from again. The crew of the USS Voyager eventually learned that these members of the Hansen family was assimilated by the Borg when they discovered Annika, then called Seven of Nine, in 2374. (VOY: "The Gift")
Changing a flight plan[]
Starfleet Command had the authority to order a Federation starship to alter its flight plan. In 2267, Admiral Komack ordered Captain Kirk to alter the flight plan for the USS Enterprise in order to make the Altair VI presidential inauguration ceremonies, which had been advanced seven solar days, in time. (TOS: "Amok Time")
In Starfleet Academy, Nova Squadron's team navigator Jean Hajar filed a flight plan with the Academy Range Officer before practicing maneuvers for the 2368 graduation ceremony on the Academy Flight Range near the moons of Saturn. The team did not follow their flight plan, and instead attempted a Kolvoord Starburst maneuver that resulted in the death of teammate Joshua Albert. A board of inquiry formally reprimanded Nova Squadron for altering their flight plan. (TNG: "The First Duty")
In 2373, a version of Odo from an alternate timeline bypassed the computer's security protocols and altered the USS Defiant's flight plan so that the ship's auto-pilot did not follow the intended trajectory. Odo did so to ensure that the ship did not time travel like intended and result in the death of Kira Nerys. (DS9: "Children of Time")
Practical uses[]
By examining the flight plan a Yridian trader filed with Deep Space 9 before departing the station in 2369, Lt. Commander Geordi La Forge was able to narrow down the potential location of Lt. Commander Worf, who was aboard the vessel and did not rendezvous with the USS Enterprise-D as planned. (TNG: "Birthright, Part II")
While on board Arctus Baran's raider, Commander Riker was able to transmit an encrypted signal to the Enterprise containing bearings and coordinates taken from the raider's navigational system. Lt. Commander Data was able to analyze the signal and reconstruct the ship's flight plan. (TNG: "Gambit, Part II")
In 2372, Captain Kathryn Janeway asked Tom Paris what his flight plan was when it was discovered the Cochrane was capable of attaining transwarp velocity. Paris replied that the second he entered transwarp, he would disengage engines and come about. (VOY: "Threshold")
Crossing into Bajoran space required permission from Bajoran Control and the transmission of a ship's authorization code and flight plan. (DS9: "Sons of Mogh")