Goofs

Kelso opens his bottle of Coca-Cola by slamming the cap against the frame of the cockpit bubble, breaking the neck completely off, but when he drains the entire bottle into his mouth (after a quick cut), the bottle neck is intact.

When Captain Birkhead and Donna get out of the car, Donna is handcuffed to an MP. Their handcuffs disappear a few minutes later, when the house collapses.

Ward loads a four-round clip in the 40mm anti-aircraft gun. He then fires one round. Yet, before firing again, he loads another four-round clip.

The "stop light" threat condition signal in the air defense coordination center is shown twice. The first time, when the trainer is incorrectly reported as enemy aircraft over the reservoir, it switches from blue to yellow on the appropriate dialogue command. A few minutes later, a decision is made to "go to red," and the signal moves from blue to red. It should have been yellow.

When the tank crashes through the front door of the house, it crashes through the upper middle of the door. When Aykroyd looks through the door a shot later, the upper left of the door is broken, with the upper middle of the door still intact.

The P-40 flown by "Wild Bill" Kelso would not have had the shark tooth paint job on the plane. This was only used by the Flying Tigers in China and would not have been used on a plane stationed in the United States.

The P-40 that "Wild Bill" Kelso flies is called a "Tomahawk" in the film. P-40's flown by US forces in World War 2 were called "Warhawks". P-40s flown by British and Soviet forces were called "Tomahawks".

Herbie Kazlminsky says that objects fall at 32 feet per second. This should be 32 feet per second per second.

Corporal Sitarski is in the wrong every time he refers to Sergeant Tree as "sir." The only branch of the military that referred to their sergeants as "sir" is the Marines.

The submarine, I-17, was not built by Germany and sold to Japan. It was laid down in the Yokosuka Navy Yard in April 1938.

Herbie and Claude change position on the ferris wheel. Spielberg did that deliberately for comedic effect.

The caption in the opening scene says it is supposed to be Northern California, however, the scenery is of Cannon Beach in Oregon at least 400 miles away.

Films often shoot in locations different from where they are actually set.

Capt. Wolfgang von Kleinschmidt speaks German throughout the film. Unless everybody on the sub speaks German too, he should be speaking Japanese.

That's the joke... he speaks German, his crewmates speak Japanese, and yet they all understand each other.

The front door of Ward's house is totally intact while it slides downhill. But in several scenes, the front door was broken several times.

After Kelso crashes his plane, he opens his parachute. The wire pulling the chute away from him is visible.

When Wally is dancing on the table, the real dancer's feet jump up as Wally jumps down.

When Angelo pushes the anti-aircraft gun back towards the house with his car, he never puts the car into gear.

In the scenes over the Grand Canyon, the aircraft banks to avoid hitting a canyon wall, yet the cockpit shots show the aircraft flying straight and level.

The tank crew has an African-American member. The US Army wasn't officially desegregated until 1948. Limited desegregation came to combat units in December 1944 and January 1945, during the Battle of the Bulge.

When Ward crashes the cannon into the house to get a better shot at the Japanese submarine, Bing Crosby can be heard singing, "I'll be Home for Christmas", which was recorded October 4, 1943.

In the USO scene, Maxine is wearing pantyhose, which were invented in 1959.

During the general's speech at the airport, a number of World War 2-era planes serve as a backdrop. Some new airliners and what seems to be a B-52 are visible in the background.

In the Ferris Wheel scene, Claude Crumn is seeing shooting at the Japanese with a Remington 700, which wasn't introduced until 1962.

As General Stilwell is watching Dumbo (1941), he says "Get out of the way. I can't see the screen." However, he can be seen saying something else instead of "screen", possibly "show."

When Donna says "You get me up in that plane, then we'll talk about forward thrust," the reflection of her mouth movements in her hand-held makeup mirror don't match her voice.

The wire guiding the torpedo can be seen.

The camera crane is reflected in Stilwell's glasses.

The reconstruction of Hollywood Boulevard has some buildings in the wrong place.

The sub shoots down the ferris wheel, it rolls down the pier, goes over the edge, and sinks pretty much in an upright position. It seems highly unlikely that the water would be deep enough for it to do so. Later, the tank falls in the water at roughly the same position, yet its turret remains above the water line. Obviously, the tank isn't as tall as the ferris wheel.