Jack goes to Odd Jobs for his latest job assignment but finds his counselor is distracted watching an internet video of Bobby being sexually assaulted by a deer. Eventually, Jack grabs his folder and sees that he is going to be a flight attendant.
Jack blogs that four out of seven people think airplane travel is not safe and he uses the phrase " No worries, be happy! " to calm himself ". Jack is at the airport dressed to work for Jetfly and meets Debbie, a stewardess who gives the impression she thinks Jack is gay. Jack is shown the list of items that are prohibited for passengers to take on board and Jack stops the first passenger and asks him to hand over his lint, which is prohibited. After that, a young boy boards followed by an extremely nervous man who refuses to let Jack handle his bag.
Jack's Grandma is driving and rear ends a SUV. After the SUV driver and Grandma exchange words, a police officer appears on the scene and Grandma reveals that she doesn't have a license.
On the plane, Jack and Debbie go over the seat belt rules in preparation for take off for a flight to Australia but when the plane does take off, Jack is not buckled in and flies off his seat to the ground.
Grandma is bailed out of jail by Jack's sister but rather than go to driver's school to get her license, Grandma immediately jumps into the young woman's car and drives off only to get into another accident moments later.
On the plane, Jack serves beverages to the passengers but when the in-flight movie stops playing, Jack acts out the plot from the movie Se7en for the passengers. Afterwards, Jack leads the young boy to the washroom and notices the nervous man is reading a book that has Fiery Death of the West in its title.
Jack's mother bails Grandma out of jail a second time and Grandma's response is to jump in her daughter's car and speed away only to get into another accident where she runs over ducks, a number of joggers and a cart containing an Amish man.
On the plane, turbulence makes Jack nervous and a passenger listing a number of things that could happen only increases Jack's edginess.
Bobby bails Grandma out of jail and tells her that his grandfather lost his driver's license and in a flashback, Bobby's grandfather has fireworks go off in his car and he plows through a Chinatown parade in his panic. Back in the present, Bobby relates that his grandfather now goes to the park and spends his time feeding the ducks and Grandma screams in horror at the thought of doing that.
Jack peers nervously at the odd man reading the book before being distracted by Debbie changing clothes near him. In his mind later, Jack imagines a number of disasters befalling the plane before being told there is a Salisbury steak situation. Jack runs into the pilot's cabin, finds the pilots drinking and grabs for the controls, which disables the automatic pilot setting. With the steep turn Jack does, the pilots are knocked out and their empty liquor bottles roll near Jack, who realizes they were drinking non alcoholic wine. Jack attempts to steer the plane in a panicky way and dumps fuel even as he pretends to be a bird for a moment.
In a park, Grandma and Bobby's grandfather feed the ducks and the grandfather reveals that he actually spends his time smoking marijuana joints and getting high, which delights Grandma. The two get stoned and steal a pair of riding lawnmowers to drive around the park.
Jack goes back with the passengers not letting on what has happened even as emergency oxygen masks drop down and turbulence increases.
With darkness falling, Grandma suggests to Bobby's grandfather that it is getting too dark to drive but the grandfather says he can fix this and reveals a large quantity of fireworks under his vest. The two use the fireworks to light a path so they can continue flying.
On the plane, Jack tries to get the pilots to wake up even as the passengers learn of what is happening. The young boy enters the cockpit and reveals to Jack that he is an air marshal. Jack is ordered to land the plane by the boy. The nervous man enters the cockpit and reveals that he is, in fact, a book publisher who is worried that someone will get hold of the manuscript he has for a new Harry Potter book. The man suggests he can read the book over the intercom to calm the frightened passengers and Jack agrees.
With no fuel, Jack and the young air marshal look to land and spot the path created by Jack's Grandma and Bobby's grandfather. The plane is landed with everybody safe and Jack heads back to Odd Jobs. Jack discovers his job counselor is laughing at the online video from the plane's black box of him pretending to be a bird. The counselor goes on to laugh at Bobby being assaulted by a horny llama and Bobby joins her in laughing.