FORT COLLINS, Colo. -- The parents of a 6-year-old boy who disappeared for hours Thursday afternoon, sounded frantic when they called 911 to report that they believe Falcon Heene climbed onto a large helium balloon and may have been in it when it lifted off.

Mayumi Heene is first heard on the call, telling the operator that her son took off in a "flying saucer" roughly 20 minutes before the call. She pleads with the 911 operator, saying, "We need to get my son!"

The operator asks if there's a tracking device on the aircraft and if the boy can steer it. The phone is then transferred to Richard Heene, who explains that his son does not know how to operate the balloon.

"We had it tethered. It wasn't supposed to take off," Richard Heene said.

Richard Heene then asks if rescuers can track the electricity that the balloon emits, even though it doesn't have a tracking system on board.

"Every five minutes, it comes on for one minute, and it emits a million volts on the outer skin," Heene said.

When the dispatcher asks if he is sure his son is in the balloon, Heene said, "We looked everywhere, and then my son just said .... and he said, 'Yeah, he went inside then (unintelligible) went off.'"

Richard Heene explained that the balloon is filled with helium, and it operates off a million volts to move left and right horizontally.

"We were testing it to find out what effect we could get," Richard Heene said.

He said the wind was pushing the silver-foiled craft straight toward Loveland Airport.

"I hope the FAA was listening to me. If an aircraft hits it, I mean ... you know," Richard Heene said, sobbing on the call.

The operator returns to tell him that help is on the way, but he's not heard from again in the call.

Hear Full 911 Call.

Below is the transcript of the 911 call.

Dispatcher 1: 911 What is the address of your emergency?
Dispatcher 2: Hi, this is Fort Collins with a transfer for 5434 Fossil Ridge Drive.
Dispatcher 1: OK
Dispatcher 2: Phone number is ....
Dispatcher 1: K
Dispatcher 2: This woman and her husband are pleading that their 6-year-old son had an experimental flying saucer that they built.
Dispatcher 1: Mmhmm.
Dispatcher 2: They believe that their 6-year-old son is in it and flying around. They left less than 20 minutes ago.
Dispatcher 1: OK. Thank you.
Dispatcher 2: He's on the phone with me now.
Dispatcher 1: OK, thank you. M'aam, what's your name?
Mayumi Heene: My name is Mayumi ... Mayumi Heene.
Dispatcher: And you're at the 5434 Stossel Ridge drive now?
Mayumi Heene: 5434 ... yes
Dispatcher: And it's Fossil Ridge Drive, right?
Mayumi Heene: Yes, yes.
Dispatcher: Is it Drive east or west?
Mayumi Heene: West
Dispatcher: OK. And so it was an experimental plane?
Mayumi Heene: It's a flying saucer.
Dispatcher: It's a flying saucer?
Mayumi Heene: Yes.
Dispatcher: And that's gone too, right?
Mayumi Heene: Sorry?
Dispatcher: Is the flying saucer gone as well?
Mayumi Heene: Um, like 20 minutes or something.
Dispatcher: They've both been missing for about 20 minutes?
Mayumi Heene: Yes.
Dispatcher: OK.
Mayumi Heene: (crying) We gotta get my son!
Dispatcher: OK. Hang on just one second. Don't hang up, OK? Just a minute.

(silence/pause)

Dispatcher: Ma'am, does it have any kind of a tracking device or anything on it?
Mayumi Heene: No, nothing.
Dispatcher: OK. Is it electronical?
Mayumi Heene: Uh, you know, you need to speak with my husband ... (unintelligible) my husband
Dispatcher: OK. I can't understand what you're saying, ma'am ... Does he know how to work the flying saucer?
Mayumi Heene: (completely unintelligible)
Dispatcher: What?
Mayumi Heene: He's calling somebody.
Dispatcher: He's calling somebody?
Mayumi Heene: Yes
Dispatcher: Who’s calling somebody?
Mayumi Heene: (completely unintelligible)
Dispatcher: Let me talk to him.
Mayumi Heene: OK.

(passing phone)

Mayumi Heene: He's coming over.
Dispatcher: OK.

Dispatcher: Hello? (unintelligible yelling) Hello? Ma'am, did you find him?
Myumi Heene: No.
Dispatcher: OK. Where was the saucer? Was it in the back yard?

Richard Heene: Uh, hello?
Dispatcher: Yes, is this Richard?
Richard Heene: Yes, it is.
Dispatcher: OK. How long has the 6-year-old been missing?
Richard Heene: Just a few minutes, uh ...
Dispatcher: Was the flying saucer in the back yard?
Richard Heene: Yeah.
Dispatcher: OK. It obviously has electronics, which he can know how to work it and he gets it up off the air? Off the ground?
Richard Heene: (sobbing) No. He does not know how to operate (it).
Dispatcher: He does not know how to operate. So, and that's gone, though, too, right? So you are sure that he's in that.
Richard Heene: We looked everywhere, and then my son just said .... and he said, "Yeah, he went inside then (unintelligible) went off." Then we had it tethered, it wasn't supposed to take off.
Dispatcher: OK. And was it running then?
Richard Heene: Well, it doesn’t run. It's filled with helium, and it operates off a million volts to move left and right horizontal.
Dispatcher: OK.
Richard Heene: And uh, we were testing it to find out what effect we could get.
Dispatcher: OK. So it was last seen 20 minutes ago?
Richard Heene: um, yeah, I'm losing track of time. Probably -- yeah.
Dispatcher: OK. So there's no electronics on it, there's no tracking device, right?
Richard Heene: No, no. Uh, I don't know if it's possible. If you guys could track the electricity that it emits? But every five minutes, it comes on for one minute, and it emits a million volts on the outer skin.
Dispatcher: OK.
Richard Heene: And uh, if he kicks it or touches it, he could be electrocuted.
Dispatcher: OK. So every five minutes it comes on for one minute and then it shuts off again.
Richard Heene: Right.
Dispatcher: And it does that too charge?
Richard Heene: No, no, no, no.
Dispatcher: OK, OK, that's OK. OK, how big is this machine?
Richard Heene: It's 20 feet across, uh ...

(Weird electronic noises in background.)

Dispatcher: And how -- I’m here.
Richard Heene: (unintelligible) feet high.
Dispatcher: OK, and the wind is going pretty good today. Which direction is the wind blowing?
Richard Heene: Hold on one second.
Dispatcher: OK.

Richard Heene: Oh, who the hell is calling me? Oh ...
Richard Heene: The wind's blowing what?
Dispatcher: Which direction is the wind blowing?
Richard Heene: It's coming southeast. So he's headed straight for the, um, the Loveland Airport. I hope the FAA was listening to me. If an aircraft hits it, I mean ... you know (sobs)
Dispatcher: Okay. So it might be headed for the Ft. Collins Loveland Airport area?
Richard Heene: Uh, yeah. I think it's just the Loveland, uh
Dispatcher: And is it silver in color, or?
Richard Heene: Yeah, it's got aluminum foil on it.
Dispatcher: OK.
Richard Heene: That’s how it gets its charge.
Dispatcher: So it's totally silver foil, right?
Richard Heene: Yes.
Dispatcher: OK. And he has no idea how to turn it or anything, is that right? No instruction has been given to him.
Richard Heene: No, no. There's no way to turn it, no.
Dispatcher: OK. And he has no idea how to land it or anything, right?
Richard Heene: No.
Dispatcher: OK.
Richard Heene: There's no communication. I mean, it was just supposed to be in the backyard, you know?
Dispatcher: Yeah.

Dispatcher: Okay, hang on just a second. Don't hang up.

(pause//silence)

Dispatcher: Sir, I'm going to go ahead ... we've already contacted the FAA. They've already been aware, made aware of it. I'm going to go ahead and call the Loveland airport and let them know as well, OK? Sir? Helllooooo? (Background noise.) Hellloooo? (Faint voices in background.) Hello?