Factual error: Listening to a radio broadcast, live, since no other indication is given, Joe Louis is completing the 12th round of a fight. This is December 6, 1941. Joe's last fight of 1941 occurred in September, his next fight was January 1942. (00:00:10)
Character mistake: Following the barricade recovery of the Corsair, the Officer of the Deck instructs the helmsman to return to course "three five oh." No line officer would use the term "oh" in place of "zero", especially when giving course change instructions.
Continuity mistake: When Lasky heads toward the conning tower, an A-7 Corsair is shown at left (and the helicopter nose has a number "3" on it). As he is led inside the tower, the camera pans up, and now the Corsair is gone, replaced by an E-2 Hawkeye (and the number "3" on the heli is gone, too). (00:06:45)
Continuity mistake: A helicopter ferries Lasky to the Nimitz, but as it takes off, it is marked as unit 9010, but in flight after passing the Arizona Memorial, it is unit 9717. (00:03:30 - 00:04:30)
Continuity mistake: There are two F-14s that deal with the yacht and the two Zeros. They are respectively numbered 202 and 203 prominently on both sides of their forward fuselages. But when one fires a missile to down the second Zero, suddenly it is number 200, a jet that hasn't been launched. (00:50:25)
Plot hole: While still unsure where and when they are, the Nimitz has two F-14 Tomcats aloft, investigating a pair of low-altitude radar contacts. They determine the planes are WWII-vintage Japanese Zeros in full military livery. The Tomcats are told to shadow the Zeros without engaging them. Then, the Captain, the XO, the CAG and Lasky all go to a formal dining room and sit down to tea. In this scene, they talk about many other 1941-era things that are happening, but nobody mentions the Zeros. That fact, and that they left their Tomcats where they did, suggests this scene was meant to be in an earlier part of the film (when things seemed odd, but no imminent threat existed) and got moved here, creating a plot hole that the USS Nimitz could slide through sideways. US Navy nuclear carrier command staff wouldn't simply go have tea under the current conditions. (00:40:30)
Revealing mistake: When the Marines shoot the Japanese pilot, you can see the wire used to set off the blood bags coming out of his pants leg as he falls. (01:11:30)
Revealing mistake: When the Zeros destroy the yacht, mooring lines can be seen holding the boat in place as it explodes. Obviously, it isn't actually at sea, but is very near shore. (00:45:35)
Continuity mistake: During the dogfight with the Japanese Zeroes, the ordnance hung on the two F-14s' weapon stations keep changing. For the weapons to change, the airplanes would have had to land and re-arm about four times during the two-minute dogfight.
Continuity mistake: As the helicopter lands on the USS Nimitz, there is no number on the nose. But as Lasky disembarks, the number "3" appears. (00:06:25)
Factual error: When Captain Yelland is shown the reconnaissance photo taken over Pearl Harbor by his own plane, it is identical to the historic photo from Commander Faraday's files. If you look at the picture, you can see 2 torpedo wakes heading towards the ship in the center of the photo. This is confirmed by the Discovery Channel's "Death of the Arizona" program. The photo was taken just as the attack began, and at this time in the movie, the attack was still a day ahead.
Factual error: Pearl Harbor is said to be 280 miles away from the USS Nimitz. An F8 Crusader on a recon mission to the harbor reports unusual shipping traffic, and that he will make another pass for a close-up series of photos. The CAG then immediately states the F8's ETA (estimated time of arrival) back to Nimitz is 12 minutes. At its maximum speed of 1,225mph, it will need to skip the second pass entirely to have any hope of returning in 12 minutes. (00:23:55 - 00:27:25)
Other mistake: Cpt. Yelland and civilian observer Lasky are trying hard not to mess up with the timeline. Changing little things in the past could have tremendous results in the present/future. However they already disrupted the natural timeline by shooting down 2 Japanese Zeros, killing both pilots, leaving behind CAG Owens in 1941 and rescueing secretary Laurel Scott who would've been killed for sure by the two previously shot down Mitsubishi Zeros.
Continuity mistake: When the Japanese pilot arrives on the Nimitz after being pulled from the water, he is bone dry as he gets out of the helicopter.
Continuity mistake: At the beginning of the movie, Cmdr Owens lands an F-14, number 200. Immediately after landing while the plane is raising its tail hook, we see the number 203 on the right wing flap, then after a short cutaway, we see the plane again taxi to the right but now the right wing flap's number is back to 200. (00:08:35)
Continuity mistake: The yacht has been blown up by the Japanese Zeros. A helicopter is sent out from the USS Nimitz to pick up the survivors. When Charlie (the dog) is being lifted into the helicopter (carried by Commander Owens) he is obviously soaking wet. When Commander Owens hands Charlie over to Laurel, Charlie is suddenly bone dry. (00:54:05)
Continuity mistake: Weapons come and go in the battle scene between the two F-14's and two Zero's. One of the F-14, supposedly 203 but marked 200, fires a sidewinder from its left side and the hard point is completely empty, it was fully loaded at the start of the combat and had only fired 1 missile. The AIM-7 Sparrow which was supposed to be there is gone, also all the AIM-54 Phoenixes that were seen earlier are gone as well. In the next shot showing 202 and 203 flying next to each other, both planes are fully loaded again, no missiles fired at all.
Revealing mistake: During the dogfight scenes, they show the pilots of the F-14. In the visor, you can see the reflection of an A-6 instead of an F-14 being used. Turns out, they dressed up some A-6 aviators as F-14 aviators for the shots.
Factual error: All the aircraft embarked onboard the USS Nimitz are part of Carrier Air Wing Eight, and carry the correct tail code 'AJ' for that wing. CVW-8 was Atlantic assigned, as was the Nimitz herself at that time. A Pacific based CVW uses the 'Nx' codes.
Continuity mistake: In the opening scene, as Lasky prepares to board the helicopter, a blue GM station wagon is seen in the background, parked in front of a yellow Pinto. Watch carefully, as the car is partially hidden by the limo. By the last shot, the station wagon turns into a Ford sedan. (00:02:20 - 00:03:25)
Answer: Apparently, the storm that pulls the carrier to another time can also catch planes in flight. It caught the planes launched to intercept the Japanese attack, and pulled them back to the future along with the carrier.