According to Denzel Washington, American company Delta Airlines granted the production team access to their official flight simulator, in order to learn some of the most common maneuvers pilots have to master in order to fly a commercial plane.
The accident in the film, was inspired by a real-life disaster, the crash of Alaska Airlines 261 on January 31, 2000. Some dialogue in the film closely resembles the CVR transcript. Like in the film, the pilots of Alaska 261 rolled the airplane to an inverted position to try to stabilize the flight. Unlike the film, however, this did not assist them in recovering the aircraft. The root cause of the crash was found to be inadequate maintenance of the airplane's stabilizer "jackscrew," which caused its treads to wear down excessively and eventually jam the jackscrew. While the pilots were trying to reach Los Angeles for an emergency landing, the treads were ripped out and the stabilizer moved to a position that forced the plane into its fatal dive.
The script was first optioned by Denzel Washington's then agent Ed Limato, who had been kicking it around Hollywood for several months until Washington showed interest. However, in order to get the film made with the studio's modest take-it-or-leave-it 28 million dollar budget, Washington and Robert Zemeckis accepted a reported tenth of their usual salaries.
In real life, Denzel Washington rarely drinks, and during an interview promoting the film, he claimed he would never play a role genuinely drunk, as the results he has seen, have been invariably embarrassing.
According to producers Steve Starkey and Jack Rapke (during a Q&A session with the Producers' Guild on October 18th, 2012), the primary airplane in the film is a pastiche of several existing commercial airliners, so as to not ID a particular plane or airline in the film. Also, no promotional consideration was paid by any of the alcohol brands featured in the movie; they decided to feature beer, wine and hard liquor brands for one shot only so as not to "endorse" any of them.
Writer John Gatins was inspired by a pilot who happened to be a fellow passenger on a flight. The pilot went on about his family life and issues, which gave Gatins pause and made him realize that whenever he is on a plane, he has to entrust himself to a stranger, who is only human, after all.
The flight number, 227, used in the movie is a common superstition to those flights that have crashed where the flight number digits add up to 11. A number of spectacular airline crashes also had this feature, such as AA 191, the DC-10 that lost an engine in Chicago and crashed in 1979, as well as PSA 182 that nosed dived into San Diego in 1978 (where the pilots and flight attendants had been drinking and frolicking the night before as overheard by passengers who got off the same plane in Los Angeles).
While the movie has been criticized for inaccurately portraying pilots and the physics of flying a plane, many alcoholics have stated that it accurately portrays addiction. Certain Alcoholics Anonymous meetings use scenes from the movie to help visualize the effects of alcoholism.
In the elevator with the small child, as Whip wipes his nose, a muzak version of The Beatles' "With a little help from my friends," can be heard. The verse begins, "I get high with a little help from my friends," right after Whip's friend gets him high.
When Nicole (Kelly Reilly) is asking Kip for some money on the set of a porn film, she is told that she should play Desdemona. Kelly Reilly once played Desdemona in a famous Donmar Warehouse production in London, with Chiwetel Ejiofor as Othello and Ewan McGregor as Iago.
When Nicole throws her purse on the coffee table, knocking over a box of drug paraphernalia, the song "Under the Bridge" by Red Hot Chili Peppers is playing. "Under the Bridge" is about Red Hot Chili Peppers lead singer Anthony Kiedis' experiences shooting heroin under a bridge in downtown Los Angeles.
When the audience is first introduced to John Goodman's character, he is listening to "Sympathy For The Devil." This song also appeared in Fallen (1998), which also starred Denzel Washington and Goodman.
When Captain Whitaker sits left seat of the cockpit, he offers his co-pilot a breath from the oxygen mask, after breathing himself, claiming it is a test. It is actually a well-known common relief for morning-after hangovers.
Whip has his alarm set for 7:14 a.m. In keeping with the "faith" theme of the film, 2 Chronicles 7:14 reads, "If my people, who are called by my name, shall humble themselves, and pray, and seek my face, and turn from their wicked ways; then will I hear from heaven, and will forgive their sin, and will heal their land." This verse perfectly fits Whip's situation.
In High Road to China (1983), the character of Patrick O'Malley (Tom Selleck) drinks heavily, and flies a plane while hungover, even flying it upside-down. These combined story elements are performed by Denzel Washington in this movie as well.
The trivia items below may give away important plot points.
Immediately prior to the stabilizer malfunction and crash sequence, co-pilot Ken Evans states that "Sleeping Beauty" has been asleep for 26 minutes, and the aircraft impacted the ground approximately seven minutes later. This is a small, but important, distinction. Prior to 2008 (four years before the film's release, but six years after the screenplay was first conceived), cockpit voice recorders on U.S. carriers were only mandated by the FAA to record the last thirty minutes of cockpit audio. This means the entire takeoff/climb sequence, in which Captain Whitaker is heard willingly exceeding safe flight parameters during severe turbulence, disregarding his co-pilot's repeated warnings, and instructing him to lie to Air Traffic Control about their flight status and altitude, would have been (just barely) absent from the CVR data, and subsequent NTSB investigation/hearing.
At the end of the movie when Whip is at his trial, when asked if he thinks Katerina Marquez drank the vodka, he says, "God help me.," which is the third step in the AA 12-Step program. The first, the admission that one is an alcoholic, is also voiced by Whip shortly after he speaks the first.
Viewers theorize that the man with cancer, in the beginning of the film, was actually God speaking to Whip and Nicole. He makes several references to believing in God and encourages Whip to befriend Nicole (without her, Whip's downward spiral would not have happened). Before leaving, he tells Nicole that she will be okay, which turns out to be true.
After his friend Harling comes to hotel "to the rescue" to help Whip wake up from his alcohol stupor with cocaine, they head downstairs while the elevator is playing the muzak version of the Beatles "A Little Help From My Friends."