It follows the exploits of the eccentric crew of the single aeroplane owned by "MJN Air" as they are chartered to take all manner of items, people or animals across the world.
[6] The story takes place at "MJN Air", the world's smallest airline, consisting of just one 16-seater aeroplane: a "Lockheed McDonnell 3-12" business jet, with the aircraft registration Golf Echo Romeo Tango India — G-ERTI — and thus nicknamed "Gerti".
The company is so small — with Carolyn joking that MJN was not so much an airline, as more of an "airdot" — that everything is run on a tight budget and they are willing to take on any job to keep the business going.
Thus Martin also has a second job with his own "man-with-a-van" business, Icarus Removals, using a van he inherited from his late father, and lives a life of poverty in a student flat-share.
[12] Douglas is also a recovering alcoholic, having been sober for a period of several years at the time the story begins, although he tries to prevent anyone else from knowing about it, fearing it will tarnish his image.
Other recurring characters include Mr Birling (Geoffrey Whitehead), who every year hires the plane to take him to see the final match in the Six Nations Rugby Union tournament.
In addition, Douglas and Martin, despite their personal differences and mutual animosity, also prove to be an effective and highly cooperative duo in some of the more dangerous situations.
Another recurring character is Captain Hercules "Herc" Shipwright (Anthony Head), a former colleague of Douglas who now works at Scottish airline Air Caledonia.
Martin concludes he is a more skilled pilot than he thought, having been struggling in the past years with a poorly weighted plane, and the solution to Carolyn's financial problems has been right under her nose all along.
In a fairy tale ending, Martin takes up his new job securing paid employment with Swiss Airways and living close to his girlfriend Princess Theresa in Vaduz; Douglas is promoted to Captain; and Herc — who accepts a downwards career move due to his affections for Carolyn — is hired as the new First Officer.
The series ends with OJS flying off into the sunset to Addis Ababa, bringing the alphabetical progression of cities full circle.
"[19] Jane Anderson of Radio Times called Cabin Pressure "the comedy series where the writing and acting are so tight they're in danger of cutting off your blood supply.
Partway to Abu Dhabi, however, Douglas realizes that, despite reminders about the cargo-hold heating, Martin has left a client's cat in the unheated hold.
Arthur, on a mission, accidentally gives the passenger a heart attack, forcing Martin to fly back and forth between Reykjavik and Boston in indecision.
Douglas exchanges orchids for fishcakes, Kieran intimidates Martin by showing some exceptional karate skills, and Arthur makes an imaginative birthday cake.
Carolyn is left to deal with a highly paranoid passenger who requests explanations for fractionally elevated arm-rests, broken glass-salt, poisoned cheesecake, and 'Goofy'.
Douglas scrapes €20 by washing the airfield manager's car, Carolyn relaxes on a deckchair and Arthur uses the engine exhausts to make boiling water which ends badly.
Carolyn is treating a yacht salesman, Mr Alyakin, on the trip to Molokaʻi, but he begins to doubt the airline's competence, while Martin and Douglas go to extravagant lengths in an attempt to make it Arthur's best Christmas ever, within seven minutes.
It's Birling Day again and Carolyn has put Martin in charge of ensuring Douglas doesn't steal the expensive whisky meant for their client.
But when the whisky does disappear and the evidence seems to point to everyone except Douglas, Martin must become the Miss Marple of MJN Air and discover the real culprit.
Carolyn meets a captain called Herc and everyone immerses themselves in exciting games whilst Martin applies a navigation-tail light onto the back of the plane.
MJN are looking forward to their day off when Mr Birling turns up demanding to be flown to Timbuktu to watch the Rugby World Cup on television so he can prove a point to his "awful wife".
Martin discovers a slight problem with the planned destination, Arthur is reading a potentially problematic book and could this be the year that Carolyn steals the whisky from Douglas?
However, difficulties with heavy rain, stubborn taxi drivers, poor phone reception, angry bees and jewellery-eating geese ensue.
An incredulous crew escort the young King of Liechtenstein and Princess Theresa to England, the latter becoming fond of Martin, but encounter a misunderstanding with fuel.
The crew must spend the night on Gerti but are distracted by uncomplicated word games — like "Fizz-Buzz", which Arthur cannot understand — and a constant alarm requiring trips out into the snow.
Between March and August 2020, during the COVID-19 pandemic, Finnemore again revived the character of Arthur Shappey for a one-man online YouTube spin-off series called Cabin Fever!