There is a terrific lowbrow summer movie hidden somewhere in "Soul Plane," in which Kevin Hart leads an all-star cast of African American comedians. The movie promises to be a sort of Ebonicized "Airplane," a fusillade of jokes and sight gags in the tradition of America's finest bonehead comedies.

Instead, "Soul Plane" is only fitfully funny, and it makes up for what it lacks in genuine humor by overdosing viewers with outrageous sexuality and outsize stereotypes. Anyone who enjoyed "Undercover Brother" a couple of years ago will agree that these aren't necessarily bad things; they just need the ballast of satirical intelligence for maximum effect.

Hart plays Nashawn Wade, a Los Angeles native who grew up in the shadow of LAX airport -- or more accurately, as a hilarious visual indicates, in the shadow of the planes taking off every few minutes. When the grown-up Nashawn sues a major airline after a disastrous flight, he wins $100 million and immediately fulfills his lifelong dream of buying his own airline. He christens it NWA, builds his own terminal complete with a chicken-and-waffle house, a 99-cent store and a basketball court, and designs the most elaborate plane cruising the friendly skies (I believe that in the official FAA glossary the correct term for it would be "pimped out").

Giant, purple, with chrome-plated wheels, the NWA plane that makes its maiden voyage in "Soul Plane" has two classes, first and low. In first class, guests sip Cristal and nibble at filet mignon while cosseted in plush leather seats. In low class, the unwashed drink Colt 45 and pass a box of Popeye's chicken; the video monitors are old TV sets, the overhead storage bins are coin-operated lockers, and some passengers even stand holding on to subway-car poles.

The admittedly ingenious set design of "Soul Plane" hits its zenith in the cockpit, where the sleepily cool Captain Mack (Snoop Dogg) flies while smoking cigarettes of questionable provenance and leaning back and listening to rap CDs; his navigator plays an Xbox. It turns out that not only does Captain Mack not know how to fly a plane, but his enthusiasm for controlled substances renders him unable to land it once the flight arrives in New York.

There are some genuinely funny moments in "Soul Plane," many of them thanks to Snoop Dogg, who between this and "Starsky & Hutch" is proving to be a surprisingly reliable supporting comic player, and comedian Mo'Nique, who plays a trash-talking, sexually harassing female security guard. And there are some fleetingly amusing gags involving Caucasians, here represented by Tom Arnold as the head of the whitest family in America (they're just returning from a visit to Cracker Land).

But for the most part, "Soul Plane" earns its laughs the lazy way, by upping the ante in raunchy physical and sexual humor. The movie's centerpiece scene, featuring a blind man (John Witherspoon) and a baked potato, clearly strives to be this year's version of the signature sequence in "American Pie." When it's not snickering at nymphomaniacal sex and the physical endowments of black men, "Soul Plane" engages in broad ethnic humor at the expense of a hotblooded Latina flight attendant and the flight's lone Arab passenger. The group that comes in for the most ribbing is homosexuals, who serve as the film's tedious all-purpose brunt.

Although Hart is an appealing presence on-screen, his nominal co-star, Method Man, isn't nearly as charismatic or likable as Nashawn's cousin, and D.L. Hughley -- who is not to be missed when he appears on Bill Maher's HBO talk show -- is completely wasted as a bathroom attendant. Still, "Soul Plane" is guaranteed to find an eager audience in viewers who, far from being easily offended, are always on the lookout for ways to mortify their sensibilities. Having been duly informed of what's in store, they are now free to move about the cabin; just keep the Popeye's and Colt 45 coming.

Soul Plane (86 minutes, at area theaters) is rated R for strong sexual content, language and some drug use.

Godfrey C. Danchimah and Snoop Dogg make the cockpit a smoking section.