Why are first episodes called pilots? Here's how the odd industry term encapsulates your favorite show's journey to the small screen

Most of us think of pilots as airline professionals flying us home for the holidays or, if we're lucky, around the world on a deserved vacation. And maybe fewer of us would associate the word with that tiny eternal flame in our gas stove. But how did the term become associated with television?

Historically, every January the TV networks enter what's called "pilot season" — when they select which scripts they'll produce an episode of before deciding to move forward with a full-season order. Hundreds, if not thousands of actors audition for a dozen projects, with only a select few shows making it to air that following fall.

Here, let us be your pilot through the world of TV pilots.

What is a pilot?

A pilot is often the first episode of a new television series. Occasionally they will be presented as extra-long episodes, sometimes in the form of a TV movie, though this was much more common in the 1970s and ‘80s than today.

In a way, pilot episodes function as guides for networks and producers to gauge what the series will (or could) become in later episodes/seasons. Creating a pilot doesn't guarantee the show will see the light of day, though in rare cases, programs of particular promise will be ordered to series before a pilot is produced. But most of the time, a pilot gives a potential show a screen test to determine its viability.

Why are the first episodes called pilots?

The television term “pilot” is likely inspired by the aviation industry, given it's the first time a show lifts off or "airs." Like an airline pilot operating a plane, these episodes steer their respective series, establishing the tone, characters, and other essential aspects of the program. Similarly in the research field, “pilot studies” are small-scale, usually private studies designed to determine the long-term feasibility of a project.

In the world of network television, a pilot is used as something of a trial run for the series itself. While it may not be the most refined or finalized version of the show, the pilot acts as a more detailed pitch to give network executives an idea of the project’s longevity (or lack thereof).

Some pilots, such as Seinfeld’s, air before a series is officially ordered and use critical reception to sway execs. Others, like the pilot for Firefly, are put through the ringer. Joss Whedon’s sci-fi series was originally set to start with “Serenity,” but execs axed that episode and had Whedon shoot a new pilot called “The Train Job.” (Serenity was later the title of the 2005 film continuation of Firefly.)

The pilot of 30 Rock was also reshot after producers decided Rachel Dratch was ill-matched for the over-the-top diva role of Jenna Maroney and recast her with Broadway actress Jane Krakowski.

What are some different types of pilots?

Not all pilots function as first-off iterations of new series. Some episodes, known in the industry as “backdoor pilots,” use pre-existing shows to introduce new characters (usually friends or family members of the main players) as a soft launch/test run before debuting a spinoff. The CSI and NCIS franchises are particularly well-known for using pre-existing series to launch new franchise installments.

One famous example of a backdoor pilot was a 1972 episode of All in the Family which introduced Bea Arthur’s Maude as a foil for Archie Bunker’s clan. Maude made such an impression on audiences that, just five months after her debut, she had her own self-titled show on CBS. Maude (1972–1978) was a success, making Arthur a household name and running for six seasons.

More recently, the TV Land sitcom Hot in Cleveland (2010–2015) aired the backdoor pilot "Bridezelka," featuring Cedric the Entertainer in a supporting role as a preacher. His character later helmed the network's series The Soul Man (2012–2016).

Related: The 10 best (and worst) spinoff shows of all time, ranked

Do all pilots function as the first episode?

Not all pilots function as first episodes, although that’s rare.

One unique example is Happy Days, which never had its own dedicated pilot. Instead, Richie Cunningham and his brood were introduced in an episode of the ABC anthology Love, American Style (1969-1974). Intended as a pilot for a completely different failed show, New Family in Town, the episode was reused in 1974 to kick off Happy Days. Regardless of its unconventional start, it still became one of the most famous sitcoms of all time. The series notably launched two successful backdoor pilots of its own: Laverne & Shirley and Mork & Mindy.

Then there's the original Star Trek series (1966-1969), which shot two pilots. After the initial one, “The Cage,” didn’t impress execs, they decided to shoot another titled “Where No Man Has Gone Before.” The latter aired as the first season’s third episode, but “The Cage” was recut into a two-parter titled “The Menagerie,” running later in season 1. "The Man Trap," which was the sixth episode filmed, instead became the first Star Trek installment to air.

There are also cases of pilot episodes ending up in cinemas. For example, the 1978 pilot of Battlestar Galactica was afforded a buzzy theatrical release overseas before it aired on U.S. television. A recut version hit American box offices the following year.

Astonishingly, David Lynch's Hollywood horror freakout Mulholland Drive (2001) was originally conceived as a television pilot for a series similar to Lynch’s Twin Peaks. But when execs rejected it, Lynch shot a different ending, turned it into a movie, and found theatrical distribution. It remains one of the late director's most celebrated pictures.

Read the original article on Entertainment Weekly