Despite what images its ignorant title calls forth, “Flyboys” is not a film about some nerdy adolescents who get bitten by radioactive mosquitoes.

Nor is it gay porn.

If it had been either, then there might’ve been some understanding of the Nicole Ritchie-thin plot and cheesy dialogue that provides a backdrop for this vagrant display of special-effects whoredom. Sadly, the closest we get to winged mutants are buzzing WWI airplanes. And as near as we come to gay is James Franco speaking bad French.

Based on a (boring) true story, “Flyboys” follows the plight of the Lafayette Escadrille, a pack of young Americans who volunteered as fighter pilots for the faltering French military. Each doughboy enlists for his own pathetic reason, be it filial worship or racial anonymity (don’t ask), and soon finds himself boarding in a grandiloquent mansion in France, where he learns to fly planes, “kill Huns” and tolerate the company of a house-trained lion (seriously, disregard the puzzling question marks in your thought bubble — je ne sais pas).

Our troupe of valiant G.I. Joe’s include daddy’s boy William Jensen (nobody #1 Philip Winchester), daddy’s unwanted fat boy Briggs Lowry (nobody #2 and #3 Tyler Labine), black boxer boy Eugene Skinner (Eugene Skinner) and Texan rebel-without-a-daddy Blaine Rawlings (James Franco). The script only requires enough “acting” to produce stupid-sounding American drawls and determined air-pilot faces. The rest was presumably done by stuntmen and FX-engineers, not to mention the makeup artist who sun-kissed Franco’s locks with perfectly subtle highlights.

Speaking of which, “Flyboys” is strike number three this year for struggling heartthrob Franco, whose last two projects, “Annapolis” and “Tristan & Isolde,” failed to obtain for him any credit as a leading man. Let’s be glad he’s on the sidelines again in the forthcoming “Spider-Man 3.” If only we could match his face with Tobey Maguire’s talent, there’d be a few extra reasons to watch “The Ape” (his straight-to-video directorial debut).

Unfortunately “Flyboys” struggles to find a single hook by which it may nab an audience (minimal practice with recently-acquired “French in Action” being at the top of my own list). Not at all funny and rarely moving, it depends on the appeal of seeing really old airplanes battle mid-air à la X-Wing star fights. Also, a semi-endearing romance between Franco’s character and a provincial maiden (Jennifer Decker) offers some arousal for the female brain. But don’t overlook the PG-13 rating because disturbing violence and sexual content (aka “the good stuff”) are annoyingly kept to a minimum.

The absolute worst thing about “Flyboys,” though, has to be its oppressively lame score. Every event in the film, even the slightest change in mood, accompanies itself with a disproportionately dramatic orchestral swelling. Brace yourself for the moments when archetypal German villain “The Black Falcon” first appears and menacingly stares through his pilot’s goggles. His signature refrain rivals the one to which “Jaws” hunted and ate people.

Deranged defenders of “Flyboys” can cite only two remotely redeemable qualities. Number one is historical significance, arguing that the more spectacular World War II overshadows the Great War when it comes to subject matter for highly publicized films. Too bad, then, that “Flyboys” evades the horrors of the trenches for a more pleasant look at “American heroes” who bravely sought glory in the air. Number two is that this film, a cesspool of mediocrity heavily decorated with special-effects, is a so-called “popcorn film,” one that requires little effort to understand and plenty of opportunities to skip to the restroom. That would make sense, except that after about twenty minutes of frenzied kernel-shoving, “Flyboys” is still running, and doesn’t stop its witless dialogue or its contrived dramatics for another two hours!

To imagine what could have filled such a priceless amount of time is to lament, at long last, the despairing condition of modern cinema, to cry in the dark over the lost potential of motion pictures and to see quite clearly all that “Flyboys” might have been — homosexual insects.