“SURELY you can’t be serious.” That line, said not by Leslie Nielsen but to him (by Robert Hays, the ostensible male lead of “Airplane!,” the movie in question), might be taken to sum up Mr. Nielsen’s career, or at least the part of it that people are most likely to remember. Of course Mr. Nielsen could be serious. “I’m serious! And don’t call me Shirley.” And that’s what was so funny. He had also, up until “Airplane!,” been a sober and solid character actor, mostly on television, sometimes playing heavies, sometimes figures of bland authority. And if not for “Airplane!” and the spoofs that followed, he would be recalled now as one of those “hey, it’s that guy” guys of an earlier era, lingering in the memory banks of baby boomers and Gen-Xers who watched way too much TV when they were kids.

Mr. Nielsen’s I.M.D.B. page lists a host of such appearances, on series whose names conjure images of urban decay and embattled masculinity: “Ironside,” “Kojak, “Cannon,” “Columbo.” He also had bigger roles in shorter-lived shows, not all of them about cops (like “Bracken’s World” and “The Virginian”). But all the curious researcher may really need to know to understand his peculiar and exemplary cultural trajectory is that he was the captain of the S.S. Poseidon.

Less than a decade separates “The Poseidon Adventure”  the grandest, goofiest and still the most watchable of the disaster flicks of the ’70s (thanks mainly to Gene Hackman and Shelley Winters)  from “Airplane!,” which appeared in 1980 to finish off that moribund genre and establish an era of spoofery that has not yet ended. By now it is likely that more people are familiar with the parody than with the “Airport” movies that were its targets, along with the older “Zero Hour!” And similarly, younger audiences (which is to say younger than 35 or so) are more likely to recognize Lieut. Frank Drebin, Mr. Nielsen’s character in the “Police Squad” franchise, than the battered paladins of law enforcement he was lampooning.