And I say that because, as with the previous Graham helo flick "Birds of Prey", there is a lot of down-to-earth, analog, seat-of-the-pants, visceral stunt flying which today would have the Screen Actors' Guild, the FAA, OSHA, CPSC, the ACLU and probably the ASPCA pitching red-faced conniptions. Helos flying under bridges downtown, trying for loops around canyon arch-bridge midspans, skidding along downtown streets between the buildings, and so on. Even for '70s and '80s standards, it was, to put it mildly, gutsy; nowadays, they'd call it "crazy", "treacherous" or "illegal as hell", and much of the production budget would be lost on fines and bail. But it all made the movie, despite the slightly-cheesy '40s-style plot laced with tension between the exes who must work together to fend off the bad guy.
To that end, I doubt, if they'd've used John Wayne as "Sam", he would've used the word "horny" as the late, great Larry Hagman did...and no gal would dare slap The Duke, real-life or scripted. So, there's Lar, with a track record of playing sleazy, easy JR Ewing to pull it off. And he takes it on the chin--er, cheek. But the acting in this film pales in comparison to the flying; to "watch for the acting" would be like watching "Baywatch" to watch David Hasselhoff act. Face it. "We know where y'all live, guys, and what grabs ya", saith Hollywood. Or its rogue element which brought us this fine piece of aviation gold, as they did with David Janssen in "Birds of Prey" in 1973.
Sometimes, the good stuff flies well under the radar of the Emmy, Oscar and Golden Globe folk. This and its prequel are two major examples. True sleepers which don't put you to sleep. Enjoy.