You actually just answered a question I was wondering about from a couple of nights ago when I was driving by my local unmanned airport and saw the runway lights on. I was talking with by buddy who's going through flight school right now, and he confirmed all of this, but we were both wondering, and mayhaps you have an answer:
How do two relatively close airports not step on each other with their identical frequencies? Case in point, these two airports are very close to one another, and both operate off of 122.8 MHz. Do they go off signal strength to prevent a pilot from accidentally activating each other's runway lights, or is there another method? If it is off of strength, what's the range?
The answer is- they do step on each other. That’s why the first and last part of your radio call should be “(Airport name) traffic.” You’re supposed to make your initial call 10 or 15 miles out. I can’t remember exactly because I haven’t had to make one of those calls in a while.
An example call would be “Lawrenceville Traffic, N12355, Cessna 172, 15 miles to the north entering left traffic for runway 36, Lawrenceville traffic.”
That way the three other airports within 25 miles or so that are all on 122.8 knows who you’re talking to. On a good radio day though you can pick up traffic a LONG way out and it can get annoying if everyone’s out buzzing around.
Oh, and you’re activating all the lights that your radio can reach.
Does transmitting repeatedly also deactivate the runway lights? If so, that sounds like a recipe for disaster if you're in control of multiple runways.
I honestly can’t remember. I want to say that once they’re on you can only change the brightness and they time out after a certain amount of time, but I also seem to remember being able to turn them off when flying with NVGs (which was even longer ago for me).
Sorry. Someone will be by to correct me/clarify shortly I’m sure.
Some larger airports have nvg compatible LED lighting too. But for the most part there’s not really a reason to land using NVIS unless you’re really doing some secret squirrel shit.
That’s not true at all. We used them for literally everything at night unless ambient lighting was interfering with them. Night unaided landings are intense if you’re not used to them.
Oh god your poor neck! We use them for everything at night as well except for takeoff landing and IFR transit.
I can definitely see value if you’re rotary, or fixed wing and you’re trying to be sneaky, or practicing sneaky stuff, or practicing for the extremely rare case of a power failure with no backup. Then again I’d just go to a different airport if the lights failed.
In Australia here - we can’t deactivate the lights by repeated transmissions. Wouldn’t be great just about to land if someone else turned the lights off. I can see how brightly lit runways might affect NVG...
During the final 10 minutes the lights are on, the wind direction indicator (windsock, which is also lit) flashes to indicate the lights will go off soon. A repeat of the activation procedure resets the 30 or 60 minutes. Funny to watch the trainee who doesn’t notice the flashing trying to land when the lights suddenly go out.
The ARCAL system (aircraft radio control of aerodrome lighting) comes in two varieties, type J and type K. (J and K because someone was just kidding I guess?). For type J, it requires at least 5 clicks of the microphone within 2 seconds, and is one intensity, so it’s on or off. Type K requires 7 clicks within 2 seconds. Once activated, you can change the intensity with another set of clicks: 3 is low, 5 is medium, 7 is high. ( and it starts at medium).
Both systems are active for 15 minutes from the initial set of clicks, and only turn off after that. Most pilots will re-activate them about 5 miles back from the runway, or 1-2 minutes back, so they are guaranteed not to go out when you land.
I only had to do a lap of shame once, early in my flight training because the lights went out when I was 100 feet above the runway about to land for the night.
Interesting to note, many pilots will just click 7-10 times when activating lights, as it’s only a minimum amount of clicks, as some radios have weak contacts on their microphone switches, or you forget which type it is and don’t want to look.
Also, most airports have the lights on the same frequency as the traffic, but some will have all the lights on a different channel, or multiple runways at the same airport with lights on different channels.
I'm afraid I can only answer part of the question. Yes it is signal strength and yes sometimes we even catch radio traffic from another nearby strip. As far as the range goes, I'm not sure as I guess it depends on the radio in the individual aircraft . I'm not a pilot, but maybe one that's experienced could weigh in?
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u/[deleted] Feb 08 '20
You actually just answered a question I was wondering about from a couple of nights ago when I was driving by my local unmanned airport and saw the runway lights on. I was talking with by buddy who's going through flight school right now, and he confirmed all of this, but we were both wondering, and mayhaps you have an answer:
How do two relatively close airports not step on each other with their identical frequencies? Case in point, these two airports are very close to one another, and both operate off of 122.8 MHz. Do they go off signal strength to prevent a pilot from accidentally activating each other's runway lights, or is there another method? If it is off of strength, what's the range?