Malcolm McDowell actually hated flying and no one, not even his wife, could persuade him to overcome his phobia. During the final battle scene between his character Cochrane and 'Roy Scheider (I)''s Frank Murphy, McDowell's grimaces were caught on film for all to see, clearly displaying his discomfort at being in the air. When his wife saw the movie, she was incredulous and asked the filmmakers, 'How did you get him inside that little helicopter? I couldn't even get him inside a plane!'
Real chicken was used during the "chicken rain" sequence. Four huge vats of barbecue chicken were lifted by crane and released over the police car and three other cars. When the scene was over, homeless people quickly appeared to help the film crew "clean up" the scene (in exchange for the chicken). No rubber chicken was used, according to director John Badham, because rubber chicken costs four to ten times more than real chicken.
The helicopter used to portray Blue Thunder was a French-made Gazelle with bolt-on parts to change its appearance. The chin cannon assembly was too heavy, necessitating a weight attached to the tail to keep the nose from dipping forward in flight.
In the sequence where Kate had just crashed through the door at the drive-in theater and two police cars spun out, you can see that one of the police cars comes very close to the camera. What you might not know was that a Japanese man, studying under cinematographer John A. Alonzo was acting as a cameraman. The spinning police car would have hit him if not for a key grip. Who grabbed his cameraman's waist belt from the back and yanked him right off his feet. Saving him from being mowed down.
At the beginning of the movie, when Murphy and Lymangood first take off (after Murphy asks "all set"), the camera is shooting up at the belly of the police JetRanger. Look closely at the registration number beneath the door. It reads "N2044C". This is the exact aircraft that would became "Santini Air" (the red-white-blue American Flag chopper) about 2 years later in Airwolf (1984).
Early in the film, when Murphy and Lymangood are in their first tour of duty. The female dispatcher who alerts them of a a robbery on Vineland and Burbank and a subsequent call is Shaaron Claridge, the same female dispatcher heard in the entire run of the TV series Adam-12 (1968). In real life, Claridge was a second-shift radiotelephone operator or police radio dispatcher at the Van Nuys Division of the Los Angeles Police Department. Her voice was also heard on episodes of Dragnet 1967 (1967), Lou Grant (1977) and Columbo (1971).
As LAPD did not want themselves mentioned, a fictional "Astro Division" designation is used. The real helicopter division of the LAPD is the "Air Support Division," however most of their missions are known as ASTRO, which stands for "Air Support to Regular Operations."
The Federal Aviation Administration (FAA) had to approve every single piece of equipment hung on the helicopter. The agency actually had inspectors checking the manufacturing of "The Special", i.e. Blue Thunder, to make sure it would be airworthy.
Although the city is Los Angeles and the action centers around the police department, the LAPD is never mentioned. The force is called the "Metropolitan Police," and their badges are silver, of a more generic style, instead of the distinctive LAPD bronze-colored badges depicting old Los Angeles City Hall. However, City Hall does figure prominently in several fly-bys.
During filming of the "ambush", where Cochrane ambushs Murphy's Blue Thunder at that incomplete skyscraper, the MD-500 Defender (the one Cochrane flew) had an engine failure and had to auto-rotate to a landing below. Fortunately, the parking lot was cleared and the pilot walked away uninjured, and the helicopter was only slightly damaged.
Despite the fact that they played characters that were enemies in this film, both Roy Scheider and Malcolm McDowell became very good friends while working on it. As McDowell would state at various science-fiction conventions, they enjoyed working together so much that they couldn't leave each other alone. When Scheider passed away, a very saddened McDowell was unable to attend his funeral due to a film project that he was working on and could not leave at the time, much to his dismay. As a result, he immediately ordered some flowers and sent a letter of condolence to Scheider's family.
The first draft of the script had a police helicopter pilot going psycho and terrorizing the skies over L.A. That was shot down by the studio, as it was afraid that the audience would not identify with a psycho main character. They did like the idea of a helicopter fight over L.A., though. The rewrite became this film.
After the original draft of the script was re-written, the character of Cochrane was added as a foil to Murphy and added the back story of Vietnam and their rivalry. Originally Bryan Brown was cast to play Cochran, but had to drop out because of a scheduling conflict with the mini-series The Thorn Birds (1983). Malcolm McDowell was cast at the very last minute and was not aware that he had to fly in a helicopter as the Cochrane character has to in the film because of his fear of flying. Despite that, he still took the role and did fly inside the helicopter.
One scene was cut after initial test screening: Kate was arriving in downtown, and instead of making a "right" as Murphy hoped, she made a left, and went the wrong way down a one-way street, and she immediately made ANOTHER left into an alley. There was supposed to be a scene were a police car blocked her off in the alley, and she did a James Bond "drive on two wheels" move to get past the police car and get to the TV station. However, audience thought this scene was too "incredible" and it was cut from the movie. It is still included in the trailer found elsewhere on the DVD, however.
When Lymangood searches for data on Cochrane, using the on-board computer, the biography states Cochrane was born in 1939 in Luton, England. The movie's director, John Badham, was born in 1939 in Luton.
Two Blue Thunders were used during in the production of the movie, and later in the short-lived series. Then, one of them was used in one episode on MacGyver (1985). And two were used as Russian attack helicopters in the 1987 TV-movie Amerika. Before the two were used in Blue Thunder, one of the helicopters was used in the movie Firefox.
The movie's closing credits state: "The producers wish to thank Mayor Tom Bradley, the Motion Picture Office, the Board of Public Works, and the people of Los Angeles for their cooperation and help in the making of Blue Thunder (1983)."