Radio Contact with Airplanes, Sour Milk

Hey, Matt:

Ever see big jets flying overhead, the ones leaving a white smoke trail? They fly right over our houses daily. Whee! Say, listen…I have a certain keen ol’ hand-held walkie-talkie, good for hiking, etc. It has a good seven-mile range and heavy-duty…top notch. Can I talk to those dudes on the plane somehow? Or is that a technical no-no, edging on an illegal type of activity, as the feds like to say? We’d like to yell, er, say to them, “Hey, jet guys! See us? Straight down! We’re waving!” Is this a yes or a no-no?

— Playful Babysitters, Clairemont

Yeah, we’ve seen jets overhead, but we never had any urge to yell at them. You might have to put that dream on the shelf, I’m afraid. Your little walkie-talkie isn’t going to be much help flagging down a pilot. First of all, your device is set to transmit and receive radio signals within a limited space in the radio-wave band. If the pilot doesn’t have a transceiver set to the same frequency as yours, he’ll never hear you. But truckers or housewives might catch your greeting. Some walkie-talkies share the same frequencies as CB radios and baby monitors. Anyway, if you have the walkie and the pilot doesn’t have the talkie, forget it.

But let’s say you ambush a pilot on his way into the cockpit and ask him to take the walkie-talkie with him. Unless you have some stupendous sales pitch, he won’t do it. Airplanes are filled with devices that rely on radio waves to operate properly. And radio waves being what they are, any off-the-wall signal introduced into the mix could possibly mess up something. The odds are small, but it’s not something that can be reliably predicted. If you convince a passenger to take the other half of your device into the sky, they’ll be hounded by the flight attendants to turn it off and will be sorry they agreed to do it in the first place. No devices that transmit signals can be used when the plane is in flight. The “airplane mode” setting on cell phones turns off the transmit function.

As we said, there’s no guarantee that your walkie-talkie signal will send the plane spinning into the ground, but there was a recent interference problem that took the airline industry a year or so to fix. One of the things that works on radio signals in the Air Bus and the big Boeing planes is the emergency lock on the cockpit door, which can be activated in case someone tries to break in. One day a mechanic was working in a cockpit and using a walkie-talkie to communicate with someone outside the plane. He pushed the talk button and suddenly the safety lock on the cockpit door slid into place. It turns out there was something about that particular frequency that could lock and unlock the safety device. The manufacturers got to work fast fixing that one.

Lastly, I know the guys who made your top-flight walkie-talkie say it has a range of seven miles, but have you confirmed that? The distance is going to depend on the power supply and also the frequency your radios use. If your device has line-of-sight transmission, you might have to go to Nebraska to test it. Find someplace that has no mountains, hills, or speed bumps for seven miles and give it a shot. Odds are the manufacturer has slightly exaggerated the power, figuring you’d never be in a situation that would disprove it. So your cheery greeting to the pilot might not even have the oomph to make it to the plane. And, hey, who’s watching the kids if you fools are out watching the skies for airplanes so you can wave and yell at them?

Heymatt:

Will milk go bad sooner if someone drinks directly out of the jug? I’ve had some sour before the expiration date lately, and I think this might be the cause.

— Pat Ryan, via email

Well, Pat, Grandma Alice is ready to come over to your house and kick some butt around. What’s the deal with drinking out of the milk jug? And by the way, we’ll have to turn down that nice dinner invitation you issued. Thanks anyway. Are you not aware that there are hundreds of species of bacteria that live in our mouths? Not to mention viruses, protozoa, and fungi. Never heard that old saw about a human mouth being “dirtier” than a dog’s mouth? When did the lightbulb go on about this situation? Yes, the backwash from drinking out of the jug will contaminate the milk and is very likely to sour it before its time. And please don’t write in again when you notice that fuzzy stuff grows on the block of cheese you put your fingers all over.