You Had Us Worried There

The Hero is defusing a bomb or outrunning an exploding freighter, or doing some other extraordinarily dangerous act of heroism. The other characters can't see him, can't detect him, and just have his radio to talk to.

Suddenly, there's a huge explosion. And silence.

The other characters ask, "Are you there? Do you read?", their faces getting grimmer and grimmer as they realize that they may be talking to nobody but a charred corpse.

But suddenly, "This is Captain Jack Amazing reporting in." The inevitable reply is, "You had us worried there, Captain."

Occasionally no reason is even given for the delay- there's no interference and the hero has had to have been safe for a minute or more, he just didn't reply for any reason but for tension. Sometimes, though, this is part of a Reentry Scare.

Anime and Manga

 * At the end of the Gundam Wing TV series' last episode, we're not sure whether Heero made it, but then he comes in with his signature, "Mission Accomplished".

Film
" The sound of a jammed filter is heard. The fish collectively gasp and swim to the filter. Deb: Sharkbait! Bloat: Sharkbait, are you okay? Gurgle: NO! Gill: Can you hear me, Sharkbait? Deb: (sobbing) No! Gill: Nemo, can you hear me?! Nemo: (appearing behind them) Yeah, I can hear you. The fish collectively gasp and turn around. Gill: SHARKBAIT, YOU DID IT! Deb sighs with relief and Bloat laughs. Gurgle: (hugging Nemo) Sharkbait, you're...COVERED WITH GERMS! (screams and swims away). The rest of the fish laugh. Gill: That took guts, kid."
 * In Finding Nemo, although this exact phrase is never used, this example is certainly reminiscent of this trope. The following exchange occurs after Nemo, also known as Sharkbait, successfully jams the filter of the fish tank:

"Jim Lovell: Please be informed, there is a Santa Claus Mission Control: That's affirmative. You're the best ones to know."
 * Occurs in The Right Stuff, when Chuck Yeager is trying to break the sound barrier for the first time. After a lot of crashes that occurred when nearing Mach 1, the ground team mistake the Sonic Boom for an explosion. Then he calls them over the radio.
 * In a more comedic example, happens several times in A Hard Day's Night when The Beatles get where they're supposed to be at the last minute. Only one or two of those were life-threatening. Also subverted once, when everyone starts reacting that way to them arriving in time for the final run-through—except there's only three of them...
 * There is also a moment like this near the end of Give My Regards to Broad Street. This one wasn't life-threatening either, but it may have been sanity-threatening.
 * In the film Apollo 13, the re-entry sequence was played like this. "Odyssey, this is Houston," being spoken over the radio, as everyone looks on in suspense. The real-life original response managed to be even more ironically mundane: "Okay, Joe."
 * The response to Apollo 11's landing announcement from the control room was "You got a bunch of guys about to turn blue, we're breathing again." It was more tense than many today realize: There were computer errors, and Neil Armstrong and Buzz Aldrin had to concentrate on piloting the lander over an unexpected boulder field; they made it down 17 seconds before it turned into an abort situation.
 * The vector-graphics arcade video game Lunar Lander seems to have been based on this very event, right down to the computer error requiring the player to take manual control.
 * And on Apollo 8, first mission to orbit the moon, the engine burn to return to Earth took place behind the moon, out of radio contact, on Christmas Day. The conversation when contact was restored:


 * In the movie WarGames, the folks at NORAD know that if the sensors are correct, various bases have just been nuked, and the delay before the answer to 'Are you still on?' comes back is pretty long...
 * A variant in Star Wars a New Hope: When the heroes are about to be crushed in the trash compactor, C-3PO doesn't lose radio contact with them, but he does mistake their cheering when the compactor stops for screams of pain.

Literature
"Old Person: One hundred years! Up yours, Baldy! Death:"
 * Parodied and Inverted in Discworld (as it is The Grim Reaper worrying about someone not dying):


 * Played relatively straight, though lampshaded, in Guards! Guards!, where Captain Vimes hears a variant of this ("You were nearly a goner there, Captain"), from Nobby Nobbs, and thinks to himself that there could be worse things to hear after awakening from serious injury, such as "Did anyone get his number?" or "You two hold his hands behind his back."

Live Action TV

 * Stargate in general loves this trope.
 * In Stargate Atlantis, during one episode (where the Stargate crew are battling a sentient computer virus) it happens twice: once when the virus tries to vent the heroes into space as they try to shut down the fighter craft the virus was using to hide in, and once when they had to fight a virus-controlled craft within the corona of a nearby star.
 * Stargate SG-1 has O'Neill jumping an about-to-explode stargate through the Earth, with a scare about whether or not he was able to eject.
 * Subverted in Stargate Universe, when they attempt to land a shuttle on a planet with extreme upper atmosphere wind speeds. There's the standard "Oh no, we're in trouble!" -> "Are you there?" -> silence -> "Yeah, we're fine." dialogue... then the shuttle loses power and crashes hard on the planet's surface.

Video Games

 * Metroid Prime 3 does this.
 * Happens in the Light Side ending of Knights of the Old Republic.
 * Several times in Mass Effect, with Shepard losing comm signal for extended periods, such as on Feros or during the final mission, with an agitated Joker calming considerably when Shepard finally gets through again.

Real Life

 * During the descent phase of Apollo 11, a number of things went wrong that you do not want to go wrong, particularly when you're many thousands of miles from home. The computer failed during the landing program, and with Neil Armstrong flying manual, Buzz Aldrin called in that they had only 30 seconds of fuel left in the descent engine. Then, in rapid succession, comes "Contact light." "Shutdown." "Okay, Engine stop." and then Armstrong's famous "Tranquillity base here, the Eagle has landed." Mission control was so wound up (and surprised by the phrasing - "Tranquillity Base" was a spur-of-the-moment innovation by Armstrong) that CapCom Charlie Duke couldn't get his words out; "Roger, Twan-- Tranquillity, we copy you on the ground. You got a bunch of guys about to turn blue. We're breathing again. Thanks a lot."