Actor Allusion: In the episode "Firehouse Four" (4x11), Johnny asks Dixie if she knows anything about singing. Her response? "A little." The actress who plays Dixie, Julie London, was a successful vocalist in real life. Also in the pilot, when Dr. Joe Early, while playing piano at a party, greets Dr. Brackett with an impromptu song. Brackett jokingly responds, "You know for a doctor he plays . . pretty bad." Early was played by noted jazz singer/songwriter Bobby Troup, most famous in the music industry for Nat King Cole's hit song "Route 66."
In "The Nuisance", John is hit in the right side, but Brackett says his left leg bones are broken
Most episode entries here have at least one or two more. They include vehicle and uniform switches, actors changing locations, a number of equipment and procedure gaffes, and actors' names getting used rather than the character names.
Cast the Expert: In most of the large-scale incidents where units other than Engine/Squad 51 appear, the other firefighters are actually firefighters. Similarly, Engine 51's driver Mike Stoker was played by Los Angeles County firefighter Mike Stoker, the captain in the first season was an LACoFD captain, and the uncredited dispatcher was really a county dispatcher.
The Danza: Firemen Marco Lopez, Mike Stoker and Capt. Dick Hammer, played by...Marco Lopez, Mike Stoker and Dick Hammer. The latter two were both Real Life firefighters, too. Hammer's character becomes The Other Darrin for at least one episode during season one. The real Hammer decided to go back into full-time firefighting and another actor, credited as "John Smith", took over the role. During the end credits of Smith's first episode, "Hang Up," he's billed as Captain Hammer. For the next episode, "Crash," Smith is credited simply as "Captain."
The Squad 51 rescue truck was built by the Universal props department to specs provided to them by the Los Angeles County Fire Department. They did such a good job that when the series was finished, the truck was donated to the LACoFD, where it put in another 20 years of service, before being retired to the Los Angeles County Fire Museum.
There was no Station 51 in the LACoFD at the time of the series, but in 1994 Station 60, which is located on the Universal Lot, was renamed Station 51.
Most people in the 70s hadn't even heard of the term "paramedic," but this show demonstrated what paramedics do and their value in real life, allowing the idea to propagate throughout jurisdictions in the United States. Modern prehospital medicine hence evolved from throwing a patient into an ambulance and hauling ass to the hospital, to treating the patient on scene and providing stabilizing treatment en route, ensuring patient survival. Nowadays, few people bat an eyelash at modern emergency medical services.
Directed by Cast Member: Randolph Mantooth directed 2 episodes; his character spent one of them in the hospital after being hit by a car in The Teaser, but he still had a lot of screen time. Kevin Tighe directed several episodes, writing another, and Michael Norell wrote 4.
The stars playing the paramedics, Tighe and Mantooth, took the regular paramedic training regime, and apart from skipping the final certification exam, were otherwise fully qualified as the real thing.
Despite being a recognizable actor in his own right, Randy Mantooth is still associated with his role as Johnny Gage to the point that he still speaks at fire service and EMS conferences, and rides along with the LAFD to this day.
Dyeing for Your Art: Kevin Tighe's hair slowly darkens over the course of the first few seasons. He was required to dye it a lighter color at first in order to play up the show's Adam-12 parallel - a strawberry-blond veteran paired with a brunette rookie. As the show gained in popularity, Tighe's hair was allowed to return to its natural dark auburn color.
Life Imitates Art: In "Fools", Bobby Sherman played an arrogant, young intern who rode with the Squad after a near-fatal diagnosis of a heart patient, and after seeing them in action, he considered becoming a paramedic. Shortly after this episode aired, Sherman left the public spotlight to become an EMT.
Lost Episode: Kind of. "Richter Six" never got filmed due to a writer's strike. Summary of the script is here. At least one scene seems to have been recycled for later, as there's an episode where Chet gets trapped in debris and hurts his arm just as in the script. Other scrubbed episodes were "The Long Weekend" and "The High Rise", although "The High Rise" appears to have been rewritten as the movie "The Steel Inferno". Info on both episodes can be found in this episode guide.
Randolph Mantooth's brother, Donald, shows up in a couple episodes playing a fellow firefighter.
Julie London and Bobby Troup were husband and wife. London was also married to producer Jack Webb before marrying Troupe.
Bobby Troupe's two daughters guest starred in separate episodes.
Tim Donnelly (Chet Kelly)'s brother Dennis directed about 18 episodes.
The Other Darrin: A minor one. The original actor playing the recurring character Craig Bryce could not appear in the "Greatest Rescues" movie due to another project, and a different actor played him when he was promoted to Captain along with Gage and Desoto. The odd thing was, the second actor was a black man.
The Red Stapler: The show is popularly thought to be the best advertisement about the merits of the paramedic program ever and lots of cities and counties started setting up their own. Pretty much lampshaded in one episode when Gage and DeSoto, after being involved in a rescue in a rural area outside their jurisdiction and which couldn't afford to run its own paramedics even after seeing their value, described a system of volunteer emergency medical responders such a region could set up to the local sherriff.
John Gage does more high-altitude rescues than Roy DeSoto because actor Kevin Tighe is somewhat afraid of heights. Randolph Mantooth, on the other hand, wasn't overly fond of spending a lot of time in the water.
John's Land Rover was Randolph Mantooth's own vehicle. It and his home in Malibu were both totaled in a rather infamous wildfire in the late 70s.
One of the show's engines remained at Yosemite National Park until 2008. Both engines and the squad are now at the Los Angeles County Fire Museum.
L.A. County Station 127 provides the exterior for Station 51, and Rampart was played by Harbor UCLA Medical Center.