(at around 56 mins) Agent Harris tells Dr. Price that they've already lost over 50 people. At that point, we have only seen 14 people killed, and in total, only 31 were killed. (26 from snakes and 5 from other phenomenon).
(at around 1h 7 mins) When Sean asks the other passengers to block the stairs from the snakes they start unloading lots of bags from the overhead compartments although the top floor of the plane was originally empty except for the two agents and Sean.
(at around 1h 35 mins) Troy leaves the plane first on the escape slide. In the next shot he can be seen inside the plane again coming down the stairs behind the crowd waiting for their turn on the slide. The DVD audio commentary claims that this error was known but not deliberate.
(at around 1h 28 mins) When the hole in the side of the plane, shot out by agent Flynn is first shown, it is on the left hand side of the plane from the pilot's point of view. This is further shown when the snakes fly out the window, as they fly out and to the left as it as shot. When the shot moves to the outside of the plane, the hole is now on the opposite side of the aircraft.
(at around 1h 29 mins) When all snakes are sucked out of the plane because of depressurization, we see pass the big snake - there was one much bigger than the others, probably a python or anaconda. That snake had been seen starting to swallow the angry businessman earlier (at around 1h 6 mins). When it is sucked out of the plane, it should be much bigger, having eaten that man.
Whenever there is a shot of the plane outside, no matter what point in the film all the lights are on, however numerous times, part or all of the plane had been plunged into darkness and it would cut away to outside and the lights would still be on.
(at around 1h 27 mins) When Flynn shoots out the windows, he shoots out two windows. When he and Troy are in the cockpit accelerating towards LA, the shot outside first class shows three windows blown out. And back inside first class, the three windows blow out again.
(at around 1h 7 mins) When Flynn and Claire are trying to pull the aircraft out of the dive, the controllers readout shows the aircraft going from 1,344 feet to 591 feet in three second. This would be a descent of over 15,000 feet per minute, or at this point 2.4 seconds from impact. An aircraft of this size has too much energy at this descent rate to be leveled off before impacting the water.
(at around 35 mins) The flight attendant is shown entering the cockpit through the use of a keypad on the forward wall next to the cockpit door. There are no keypads in actual aircraft as that would defeat the purpose of having a security door, since a hijacker could possibly get the code by watching the crew enter, or by forcing a cabin crew member to open it under threat. The cockpit door is controlled electrically (or mechanically) by the flight deck crew only. This is a requirement of the hardened cockpit door design.
(at around 31 mins) When the aircraft loses power, the cabin is shown to go completely dark. This would not happen as these size aircraft have emergency lighting in the cabin and on the flight deck which is activated by the loss of normal aircraft electrical power. They are self contained battery types, they come on automatically and remain activated until turned off by the crew, and there are numerous independent sections of them on an aircraft.
(at around 1h 3 mins) After the first officer is incapacitated, the aircraft is shown in a steep descent. It goes from 32,400 feet to 26,200 feet in approximately three-quarters of a second. That would translate to around four hundred ninety-six thousand (496,000) feet per minute, or four thousand nine-hundred and sixty (4,960) knots vertical velocity. The aircraft would have come apart long before this speed, as it is impossible to achieve that in this kind of vehicle.
(at around 1h 27 mins) If the aircraft did in fact undergo catastrophic decompression as shown, the cabin air would go milky white for a few seconds. This is due to the reduced pressure in the atmosphere bringing the moisture in the cabin to a point where it is visible, like when opening a soda can and seeing a brief flash of visible vapor.
(at around 1h 27 mins) Flynn tells the passengers to hold their breaths before he shoots the windows, thereby depressurizing the interior of the plane. In reality, if a person holds their breath during depressurization, a 'lung over-expansion injury' can occur. This is why scuba divers are taught "Never hold your breath".
(at around 1h 3 mins) The controllers use the phrase "nineteen-thousand feet". This is incorrect as any altitude starting at eighteen thousand feet is referred to as a "Flight level". Thus he would say "Flight level one-niner-zero". Flight levels are used at these altitudes to eliminate altimeter differences due to local barometric pressure setting changes.
(at around 1h 27 mins) If the air was rushing by as rapidly as depicted during the depressurization sequence, no one would be able to remain standing against the force. Additionally, with a hole that large in the fuselage, the pressure differential would equalize rapidly, literally in seconds. No amount of differential would be able to pull the snakes off of the floors and out of the cabin as depicted. This much pressure would collapse the floors and walls in the aircraft's interior, and would quite likely create so much structural damage to the aircraft that it would destroy the plane.
(at around 31 mins) When the aircrew lose avionics, they report it to LAX (Los Angeles Airport) despite being 1500 nautical miles out. At that distance they would be nowhere near the LAX Air Traffic Control. LAX would only be contacted once the aircraft was about to enter the controlled airspace around the airport itself.
The exterior shots of the aircraft show a 747-400. The interior, however, features a circular staircase between coach and first class. The circular staircase was discontinued and replaced with a long, straight staircase when Boeing introduced the 747-400.
(at around 1h 4 mins) Air-Traffic Controllers never give pilots instructions on how to fly their aircraft. They will never tell anyone to "pull up", at best they would ask the crew to check their altitude or confirm they were aware of the descent. For that, passenger jets are equipped with a Ground Proximity Warning System, GPWS, which automatically tells pilots to pull up if they're too low.
(at around 1h 1 min) Mercedes uses a smartphone to photograph dead snakes and send the pictures to Dr. Price. Smartphones only operate within range of cell phone towers, of which there are none over open ocean.
(at around 20 mins) The crew would not give an abbreviated briefing as shown, as it would violate Federal Aviation Regulations. Briefings must actually demonstrate the use of seat belts, must point out all of the exits and not just state there are "several emergency exits", must reference oxygen use for self and those that need assistance, and must ask that the passengers follow along on the briefing card. Also, they must state what type of aircraft the passengers are in. None of this was done in the briefing.
The Pilot and First Officer both descend into an avionics bay below the cockpit, however the cockpit on a 747-400 is on the upper level of the plane with only a couple of feet between it and the first class cabin below. Also the upper deck of a 747 is not a widebody configuration as shown in the film.
(at around 1h 19 mins) When Flynn goes down into the cargo bay and resets the outflow valve circuit breaker, it is shown to be a large industrial type electrical switch such as is used in house or commercial structures. There are no breakers like this on any aircraft. Instead they use remote controlled circuit breakers to control large electrical relays in the system. In addition, the ceiling of the "cargo bay" shows taped drywall joints and the walls appear to be cinder blocks - materials highly unlikely to be used on a modern aircraft.
(at around 1h 30 mins) Troy's ability to fly is supposedly based on his 2000 flight hours of a flight simulator on the Playstation 2. There is no game or flight simulator for the Playstation 2 that is nearly detailed enough to prepare someone to fly and land a 747. Also the level of detail in terminology, complex knowledge of landing practices, and identifying runways, as well as the complex controls of the plane, would not be present in a Playstation 2 game. Even a pilot who actually flew all the planes listed by Troy would likely have at least some trouble flying such a large plane.
(at around 1h 9 mins) The Snake Expert is looking on his laptop at the world's most deadliest snakes, but a picture of a Scarlet King snake can be seen mixed in with the other pictures. The Scarlet King Snake is not poisonous. (You can tell by the stripes clearly what kind of snake it is.)
(at around 1h 4 mins) Controllers displays are not in color, do not show a compass ring around each target, and do not have an arrow pointing in the direction of travel. They also do not show the terrain as if looking at a map, but rather they have minimum safe sector altitude blocks that the aircraft are shown in. The display will also show the aircraft's ground speed displayed within the data block.
(at around 1h 3 mins) The altimeter is shown at 37,000 feet, but the Kholsman window (where the selectable local barometric pressure setting is seen) shows a setting above thirty inches of mercury. This is incorrect, as it would be set to 29.92 (standard barometric pressure) when the aircraft reached 18,000 feet and entered the flight levels.
(at around 1h 4 mins) The air traffic controllers display shows the aircraft's on-screen altitude warning changing from yellow to red when the aircraft is descending through one thousand feet, but shows it changing back from red to yellow at five hundred feet when the aircraft climbs. The controllers display shows numerous aircraft altitude readouts displayed down to the foot, e.g. DMA 134 is shown at 9719 feet. Controllers readouts show the altitudes only down to the hundreds of feet. Thus 9719 would be shown as ninety-seven hundred (actually it would be depicted simply as 97 in the data block).
(at around 1h 30 mins) The FBI helicopter, a private jet, and a medevac helicopter are all shown with registration numbers, tail numbers, beginning with the letter Z followed by four numbers. All aircraft registered in the United States, as an FBI helicopter should be, have tail numbers beginning with the letter N. Further, there are no countries whose tail number format begins with the letter Z followed by four numbers.
(at around 1h 30 mins) When wanting to land at LAX, you would speak to the Air Traffic Control Centre in the order as followed: - LAX_CTR, LAX_APP, LAX_TWR, LAX_GND. Whereas, it seems the same air traffic worker has the job of what 4 different people should, and LAX_CTR isn't even in the Airport's main tower.
(at around 23 mins) It is stated by the crew that they are coming up on "Thirty-thousand feet". The shot of the altimeter immediately following shows an altimeter with the hundred-foot needle going through the 800 mark. The thousand-foot needle is on the 35,000 foot mark (a five thousand foot difference), and the thousand-foot needle does not move when the hundred foot needle moves.
The aircraft shown is a Boeing 747-400. The Federal Aviation Administration (FAA) of the United States requires a ratio of one flight attendant for each 50 passenger seats on every flight. An aircraft of this type would usually have around 500 seats. This means there should be around 10 flight attendants, or more. However, only four are shown throughout the film.
(at around 28 mins) When the couple is in the lavatory to join the "Mile high club", the guy reaches up and pulls out the smoke detector located in the ceiling so the couple can smoke a joint. Tampering with the smoke detector in this fashion triggers an alarm to the crew as this is a federal offense, and would be immediately investigated.
(at around 1h 35 mins) The herpetologist, Dr. Price, is shown giving medical directions to the paramedics when the passengers are coming off of the aircraft to be treated. He is identified as "the leading snake expert in the area", so most likely he would hold a PhD in the subject, and not an M.D. If he is in fact an M.D., he is shown to call out for "Lactine and Ringer's solution" to be administered. The actual term is either "Ringer's Lactate" or "Lactated Ringer's solution". This is a standard and common IV solution, and an M.D. would never make a mistake in something as common as that.
(at around 13 mins) Just before takeoff, some personnel pass the information "Flight 121" to identify the target-plane via radio to the killers. In fact, the special luggage with the snakes would not be able to change planes any more at this time.
(at around 23 mins) An altimeter is shown inside the box with the snakes triggering the clock which opens the box 2hrs later. Altimeters calculate the altitude based on air pressure, and since in airplanes like this the whole interior including cargo area is pressurized, an altimeter would not show 30-35,000 feet, only 5-7,000 feet.
(at around 44 mins) The snake that is handled and put into the microwave is a Scarlet King Snake. It isn't poisonous, but looks like a Coral Snake. It is often used in snake movies in shots where actors have to handle snakes, or shoot close ups with snakes.
The goof item below may give away important plot points.
(at around 1h 35 mins) When Flynn shoots the snake at the end, blood sprays all over his buddy's shirt, covering the writing he had on it. But when he slides to the end of the escape slide, blood is only on his shoulder area, and the writing on his shirt, is clearly visible. Then when he is helped off, and laid on the ground, the blood is back, all over the writing.