During a fierce thunderstorm, Sky picks up a mayday call from a Air Force courier plane which is about to run out of gas. The Air Force request Sky's assistance in locating the downed aircraft because the pilot is transporting secret documents that are of interest to foreign governments. Sky locates the plane wreck, but the pilot is nowhere to be found. When he discovers that the navigational instruments have been tampered with, Sky fears that enemy agents may have located and stolen the secret plans and are headed for the nearby Mexican border.
When Penny discovers a wounded carrier pigeon carrying a valuable ruby attached to its leg, Sky suspects a gang of jewel smugglers is operating in the area. With the help of a Mexican police detective, Sky sets up to break up the criminal operation.
A crooked express agent fakes a hold-up to steal gold from his company's vault. He uses an old stagecoach to get the stolen loot out of town.
While helping a friend run his freight airline after an accident, Sky stumbles across a gold-smuggling operation.
Sky's efforts to prove corruption in the county clerk's office nearly result in disaster, when Sky's foreman, a non-pilot, must land the Songbird when Clipper becomes too ill to fly the plane.
Sky becomes suspicious when a Eastern woman shows up in Grover claiming to be the long-lost niece and heir of a dead rancher.
Penny picks up the wrong suitcase at the airport and discovers it's full of counterfeit money. Sky suspects that a young former engraver might be involved.
A rancher disinherits his nephew in favor of his young son. When the rancher is murdered the young man is blamed. Sky hopes that by faking a jailbreak, the real murderer will be forced into the open, but the plan backfires when Clipper and the young man are kidnapped.
Sky King picks up a young hitchhiker who refuses to divulge his identity, or where he's been or going. Determined to fill in the blank spaces on the young man's resume, Sky learns that he is an escapee from a boy's reformatory who was involved in a recent bank robbery.
A young rancher disappears after the man attempting to foreclose on his mortgage is murdered. Sky is convinced that the man is innocent and that there's another explanation for the man's apparent flight.
Eastern gangsters set up a protection racket near Grover and the local ranchers appeal to Sky for help.
The drug Sky delivers to a critically ill man does more than save his life; the medicine causes the man to confess that he's a former criminal who has attempted to go straight.
Angry that Sky and Clipper won't allow her to join the search for a missing refugee professor, Penny slaps on a pair of six-shooters and launches her own investigation.
Penny sees a man escape from a doctor's office, and is informed that the man is a dangerous mental patient. Sky looks into the incident, and soon finds himself mixed up in foreign spies and poison gas.
Sky investigates a series of mysterious payroll robberies, where the police chase the robbers only to see their getaway car mysteriously disappear.
A local banker is blackmailed by two former confederates who aware of a crime he committed over twenty years ago and was never apprehended.
A couple of Easterners claim to have traveled west to visit a dude ranch, but are actually a pair of con artists willing to commit murder to obtain a ranch with a rich uranium deposit on it.
Sky teams up with a military intelligence officer to track down a foreign agent who blew up a secret government project.
Sky stumbles across a dead pilot and suspicious looking plane wreck and discovers that the man was murdered and the crash never happened. He learns that the plane was carrying a number of valuable pieces of ancient Chinese art, all of which are missing from the plane's cargo hold.
A young bandit in Sky's custody.
A local boy is kidnapped by convicts on the run.
SOS in a ghost town.
A medicine man must bring rain.
A map to uranium mines is stolen.
A code of silence hinders terrorized local Chinese.
An émigré scientist is blackmailed.
Sky tracks down robbers who have taken an old miner hostage.
An old miner transporting ore through the desert.
A state of the art operation.
Tales of the past lead Sky a merry chase.
A foreign agent boobytraps Sky's car at a military weapons testing facility.
A convict seeks vengeance.
A new way to ferry valuables.
Sky rescues a gang plotting a bank robbery.
Before a missile test, one of Sky's guests is an impostor.
A show holdup turns legit at the Rodeo.
Horsethieves.
Mexicans face involuntary servitude.
Someone has sabotaged a young rancher's harvest.
A thoroughbred in a canyon.
Sky pilots a Navy jet to stop a lookalike flying with explosives in the Songbird toward a military base.
Sky and Penny are held captive by a maniac planning to dynamite a waterworks.
A film unit on location isn't everything it seems.
An oilman faces opposition.
The way to find a boy in the desert is with the Songbird.
Mind over matter at the county fair.
Sky's on the trail of a homing pigeon carrying a jewel.
An unusual suspect description leads Sky and Penny to the big top.
A land dispute takes some investigating to settle.
A little girl pines away for her absent father.
Sky fills in for an injured athlete.
A famous magician hocus-pocuses a diamond.
Philately and the press.
Strange phenomena under investigation.
A fugitive under a misapprehension flees to Mexico.
Trouble in the works.
Sharpers lay a snare.
Davey heads for the hills with desperadoes at his heels.
Dynamiters kidnap Penny.
Someone is against a logging company.
A charity pilfered by an air racer.
A seeing-eye dog trails a stickup artist.
Nuptials are interrupted by kidnappers.
An undercover job to protect cargo pilots.
Trouble in Reno for a ranch hand's boy.
Penny is hijacked on a friend's yacht.
The driver has taken an overdose of sleeping pills, and the truck is full of children on a picnic.
Coyotes attack Sky's livestock.
Overheard mischief on an airliner.
A stolen car ring.
A chief refuses medical treatment.
At an amusement park, smugglers put one over on him.