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.

Sky attempts to help a young man recently paroled from prison get started again, but the ex-convict's former friends frame him for a bank robbery.

Sky King and Penny turn the tables on foreign agents conspiring to blackmail a refugee scientist.

A young rancher is losing cattle fast so Sky King investigates.

Sky and Penny unwittingly become involved in sabotage when they visit their friends Major Dave and Denise McKay. An enemy agent has attached a time bomb to Major McKay's car, setting the fuse to explode while the Major is working at an army special-projects base. When Denise and Penny borrow the Major's car, they are placed in grave peril.

During a major flood, Sky, Penny and Bob assist the authorities in their rescue efforts. Unfortunately, three of the men they rescue are murderous escaped felons who force their rescuers to help them rob a flooded bank.

A mock holdup paves the way for a real holdup and Sky King comes to the rescue.

Someone has sabotaged a young rancher's harvest and Sky King sets out to find the culprit before any more damage is done.

Sky and Penny are held captive by a maniac planning to dynamite a waterworks facility.

Sky investigates some suspicious happenings at the county fair.

After a bird with an emerald attached to its leg lands in penny's garden, Sky King releases it to see where it goes.

Fearing he has killed another boy, Joe Belden, recently released from reform school, flees into the desert. Sheriff Hargrove knows that the Joe's opponent survived the fight, but also knows that Joe, now heavily armed, will think that the law officers are intent on arresting him. He calls upon Sky, whom Joe trusts, to join the man-hunt.

Sky and Penny try to clear a gentle, animal-loving "wildman" who has been blamed for the robbery of a logging company payroll.

Sky and Penny enter an air race, and it's soon discovered that the main office has been robbed and all of the receipts have been stolen. Sky suspects that one of the contestants in the race is the culprit and is using the race to make his getaway.

Sky follows the seeing-eye dog of a blind newsboy, who he believes will lead him to a holdup man living with a party of wolf hunters.

Sky is holding a wedding at the Flying Crown Ranch. The ceremony is interrupted, however, when two gangsters kidnap the groom and threaten his fiancé.

Four pilots for Wellman Air Freight Lines are injured in the first month of a contract for the company to carry s large payroll. In order to find out what's going on, Sky goes undercover as a security guard.

While Sky is training with his naval reserve unit, Penny visits friends who cruise Central America on their large sailboat. When three escaped prisoners commandeer their vessel, it's up to Sky and the U.S. Navy to rescue his niece and her friends.

When marauding coyotes begin to kill his calves, Sky hires two flying bounty hunters to kill the animals. When more dead calves are found, Sky discovers that the men he has hired are using his ranch to smuggle jewels, not kill vermin.

Young Mickey, a distant relative of Sky's, is traveling to visit the Flying Crown Ranch while his guardian is out of the country. En route, he overhears two men discuss shooting a foreign visitor and is determined to warn the man of his peril.

Sky tries to help an old Indian chief who is very sick, but he won't go to the hospital for treatment because he would rather die on his own tribe's land.

While visiting an amusement park on his birthday, Mickey wins a model airplane at a shooting gallery. Unfortunately, two smugglers have hidden a valuable pearl in the airplane and will stop at nothing to get it back.