Race for the Yankee Zephyr

Quoting The Other Wiki, "Race for the Yankee Zephyr (also known as Treasure of the Yankee Zephyr) is a 1981 action–thriller film directed by David Hemmings and starring Ken Wahl, Lesley Ann Warren, George Peppard and Donald Pleasence."

Barney (Ken Wahl) and his alcoholic partner Gilbert (Donald Pleasence) are helicopter pilots in New Zealand, netting deer from their decrepit Mixmaster. After Gilbert is accidentally hoisted up instead of a deer and dumped into a lake, he stumbles across the wreckage of the Yankee Zephyr, a crashed DC-3 from the Second World War.

Gilbert retrieves some of its cargo of medals (along with a crate of whiskey) and is impressed when an antiques dealer pays him $75 each for them. Convinced he's onto a good thing, Gilbert talks his daughter Sally into financing the necessary repairs to their helicopter so he and Barney can salvage the rest of the medals. But things get complicated when a gang of well-dressed, well-armed and well-equipped hoods, led by the urbane Mr. Brown (George Peppard) arrive on the scene, sparking a dramatic race via air, land and water for the real prize of Yankee Zephyr -- the payroll of the US South Pacific fleet, $50 million in gold bullion.

Tropes used in Race for the Yankee Zephyr include:

All That Glitters: Inverted -- the treasure is actually far more valuable than the protagonists imagine, but they don't discover this until the end of the movie.
Bait and Switch Gunshot: One of the mooks appears to be getting ready to shoot Gilbert from a helicopter. After the shot is fired we see Gilbert hit by a deer-trapping net.
Bar Brawl: Gilbert demolishes a pub while fighting with Barney, including slicing the front door in half with a chainsaw. One cliche is averted when the patrons cheer them on instead of joining in.
Be Careful What You Say: Sally, alarmed by Barney's low altitude flying, demands to be put down. Moments later they crash.
Cool Car: After their helicopter crashes, Gilbert gets some Mr. Fixit friends to transform its cabin into a caterpillar-tracked all-terrain vehicle.
Cut His Heart Out with a Spoon:

Brown: "Allow me to give you two options. Either a) you stop this childish prevarication and lead us directly to the Yankee Zephyr, or b) I shall find your daughter, break every fragile little bone in her body, and then you shall lead us directly to the Yankee Zephyr."

Damsel Scrappy: Sally. Though her powerboat skills come in handy towards the end.
Empty Quiver: Barney suggests Brown is after an atomic bomb. When Brown casually replies "Yes, if you like", Barney immediately rejects this as the atomic bomb hadn't been invented in 1944.
The End - or Is It?: Brown appears to drown at the end, but midway through the credits he pops up in a lifevest, shouting for his mooks to come and rescue him.
False Reassurance: Brown is fond of this, like saying he deplores violence (after watching Gilbert get beaten up by his mooks) then threatening to do something nasty to Gilbert's daughter. On first meeting Barney he claims to be a paragon of patience, then after Barney proves stubborn says that his patience is running out.
Gilligan Cut

Gilbert: "Well it's a bit tricky. You see, the first time I saw the Yankee Zephyr I was suspended arse-over-elbow underneath a Mixmaster."
Brown: "That can be arranged." (cut to Gilbert tied up in a deer net beneath Brown's helicopter)

Kung Fool: A mook catches Barney sneaking up, intent on braining him with a lump of wood. Instead of grabbing his rifle, the mook begins waving his arms about and howling in a highly exaggerated martial arts style. Barney gapes in astonishment then, as the mook turns to deliver a spinning kick, boots him down the mountainside.
Man of Wealth and Taste: Brown's first line is a complaint that the mook sent to greet him is too ugly. He spends half the movie with a martini glass in his hand, including when he's traveling down the river in a dinghy. The impracticality of Brown's luxury is spoofed when, after calmly threatening Barney at his deer farm, Brown climbs back in his expensive limo which then can't drive off as it's bogged down in the mud.
Meaningful Name: Brown introduces his henchmen as "Mr Broken Teeth, Mr Ruptured Spleen, and my right-hand man -- Mr Rape Your Daughter With Assault Unless You Play Ball."
Newsreel: The film opens with an RKO newsreel about the Yankee Zephyr and its cargo; an aerial shot of the aircraft ends with smoke pouring from the engine as it vanishes into the clouds.
Rare Guns: The only movie (to this troper's knowledge) that shows the AR-10, a 7.62mm Armalite assault rifle that preceded the M16.
Save the Villain: Averted -- Sally implores the others to do this as the Yankee Zephyr sinks, but Barney and Gilbert refuse.
Scenery Porn: The mountains and rivers of New Zealand, two decades before The Lord of the Rings.
Squick. Gilbert describes the eating habits of the crocodile in disgusting detail to everyone he meets. Later used as a combination We Need a Distraction / Pre-Ass-Kicking One-Liner when Barney and Gilbert are confronted by armed mooks at a roadblock.
Surrounded by Idiots: Brown is exasperated by the frequent bungling of his henchmen. The crowning moment is when one of his mooks accidentally shoots a hole through Brown's dinghy and the flotation bags holding up the Yankee Zephyr. While they're in the middle of a lake.
Unbearable Prisoner: The villains try to force Gilbert to show them where the Yankee Zephyr is, only to have him lead them round in circles for days.
Unusual Euphemism: Gilbert describes Sally's mother (his second wife) as having a big pair of...lungs.
Villain Ball: Brown and his chief henchman fighting over the Yankee Zephyr as it sinks instead of swimming for safety.
We Need a Distraction: Sally is told to fire a captured AR-10 in the air while Barney sneaks in to rescue her father, but she's unbalanced by the recoil and shoots up the villains' camp instead.