Factual error: Aboard the aircraft carrier, there is a closed-circuit TV that shows the operations on the flight deck. At one point, a gull-gray F-14 Tomcat, in obvious distress, comes in for a landing. The camera cuts away from the TV to Ryan's face, and the cuts back to the TV. All of a sudden, the plane crashing is no longer an F-14, but an old Korean War-era fighter (F-9F Panther of VF-21), colored the dark blue the Navy stopped using in the 1950s. The director chose to insert a piece of stock footage from George Duncan's crash on the deck of USS Midway (CV-41) on July 23rd, 1951 rather than build a model F-14 to crash for an otherwise unimportant scene.
Factual error: When Jack Ryan is chasing the Cook's Assistant Igor Loginov through the missile compartment, the compartment shown does not exist. Russian Typhoon submarines (of which the Red October is a variant, just with a new propulsion system) have a pair of cylindrical pressure hulls - each containing a missile compartment - on either side of the missile tubes. The location where the fight takes place in the movie would be inside a flooded ballast tank in a real Typhoon.
Factual error: At the beginning of the film Jack says goodnight to his daughter and then leaves for the airport to catch the flight to Washington. He arrives at Heathrow in the dark. A flight to Washington From Heathrow takes 6-7 hours, and Washington is 5 hours BEHIND London. If Jack leaves at, lets say, 10PM London time, he would arrive at midnight US time. But in the film he's met upon arrival and gets straight into a car at the airport and drives to the CIA offices for his meeting with Greer. The problem is it's daylight when we see the car driving to Langley, which is a relatively short drive from Washington and the Airport (s) - where did the night go?
Factual error: Regardless of the factual error about the visible distance in Atlantic waters, just before the Red October and the Dallas communicate via Morse code, there is a scene where both submarines are diving upwards. The two submarines are hardly more than 50 yards apart even though, only a few seconds earlier, a crew member said that they were about 300 yards apart.
Factual error: When the USS Dallas submerges to attack the Red October, they rig for battle stations as well as rig for red. On a submarine, rig for red is only for periscope depth operations at night, to allow control room watchstanders eyes to adjust to the darkness topside. No other area on the boat rigs for red. Throughout the movie the lights darken along with battle stations. No naval ship would reduce visibility on purpose in a heightened state.