Pilot of the airwaves, signing off forever.

After 48 years of broadcasting, WPLJ/95.5 FM enters radio silence Friday. The iconic Manhattan-based station was among a recent $103 million cash purchase by Educational Media Foundation, a religious programmer, of six Cumulus Media stations. At 7 p.m., the station will join the K-LOVE network and play Christian contemporary content.

“It’s a tough day — it’s been a long run,” Joe Pardavila, executive producer of the station’s “Todd & Jayde in the Morning” show, tells The Post.

“It’s hard for our audience; PLJ was part of their life, their morning routine, their afternoon routine,” says Pardavila, who started at the station as an intern 24 years ago.

Longtime listener David Bookbinder, 53, runs a Facebook fan page for the station. “In my heart it closed in ’83, when it switched from classic rock to top 40 and I was a senior in high school,” he says. “That was the real day the music died.”

Today, Bookbinder acknowledges, the music dies again: “It’s sad. It was still a New York institution.”

Bookbinder fondly recalls the 1979 “Paul Is Dead” special, interviews with members of The Who after Keith Moon’s death, and the “King Biscuit Flower Hour” as the most definitive moments of PLJ’s rock-and-roll legacy.

The station’s call letters were derived from “White Port and Lemon Juice,” a 1950s R&B song covered by Frank Zappa and The Mothers of Invention. Friday will mark the first time it’s gone dark since December 1980, when Yoko Ono requested 15 minutes of silence after John Lennon’s murder.

“The station played nothing but Beatles and John Lennon music for the longest time, several days,” after Lennon was shot, recalls Jimmy Fink, who worked at PLJ for 13 years.

“Yoko got in touch and asked that we observe 15 minutes of silence on the Sunday afternoon after John was killed,” he tells The Post. “It was a very eerie feeling, sitting in the studio, broadcasting dead air. We came out of it with a John Lennon song called ‘Love.’ ”

Fink began at the station in its previous incarnation. “I started before it was PLJ, in 1970,” he says. Then, the wavelength was WABC-FM.

“It was a free-form rock station, they called it the ‘love’ format, originally, which is weird, ’cause it’s changing to K-LOVE now,” he says. “What goes around comes around, I guess. Even radio stations don’t last forever.”