Economical Runway Lights and Position Thereof

timwinters

timwinters

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As some of you who frequent purple may know, I have a piece of property under contract just outside of Conway, MO that will allow for a 2,000' strip. I'm starting to research runway light options and the possibility of going solar...solar would avoid a $2,500 expenditure for 5,000' of 12/2 direct burial wire before I even think about buying or making the fixtures themselves.

Two questions regarding this...

1. Does anyone have any 1st hand experience with solar lights that actually work and are durable? I gotta believe that the cheap walmart or harbor freight stuff would be a waste of (very little) money because they don't appear to be either durable or bright enough to see from the distances required for runway marker lights. My current design will require 30 lights.

2. The prevailing design of lit grass runways that I'm familiar with, is to install yellow cones like these:
51.jpg
at a 200' spacing with the lights mounted 1/2 way between the cones on frangible posts.

Why not just mount the lights on top of the cones?? It would be less to mow around and, if I decide to go hardwired, the direct burial wiring could be brought up to the light inside the cone eliminating all need for conduit. Am I missing something when considering this? (BTW...I already have 50 of these cones, more than enough for the runway and a windsock circle.)

Thanks in advance for any input.
 
I've seen solar lights at military fields that seem to last most of the night, so it's possible. I have no idea how much a light fixture would cost though. Prior to leaving Alaska in 2004 I heard talk of putting solar lights into some of the villages that didn't have lights. Again, I have no idea of the cost, but I believe it was supposed to be an economical solution for them.

First though, think about whether you would actually be using the strip at night.
 
The only off-grid small strip night lighting I have any experience with is when a neighbor parks a 3-wheeler at the end of the strip and shines the lights.

I've never seen a self-contained solar light that was worth owning, and I bought a bunch before I gave up and went with a hard wired low voltage solution.
 
The big maintenance expense with solar lights is the internal batteries. My experience with inexpensive yard lighting (which is probably not bright enough) is the rechargeable batteries need replacing every 6 months or so.
 
I'm curious to see some good ideas here as well; I live on a 4000'x100' grass strip airpark with home made LED/solar lights. The lights are adapted to use standard runway light fixtures and used to work well... but as they've aged, they've dimmed or died out completely. With the age of these lights, do the LEDs fade out or is it more likely that the batteries are toast? The original builder of these has no interest in fixing them, so alternative solar/LED ideas are handy.

Or, if we were to go the standard route and run wires for electric lights, anyone have a rough idea of the trenching and wire cost for approx 8200 feet of wiring? Located N of Houston, TX if that helps...
 
jbDC9 said:
I'm curious to see some good ideas here as well; I live on a 4000'x100' grass strip airpark with home made LED/solar lights. The lights are adapted to use standard runway light fixtures and used to work well... but as they've aged, they've dimmed or died out completely. With the age of these lights, do the LEDs fade out or is it more likely that the batteries are toast? The original builder of these has no interest in fixing them, so alternative solar/LED ideas are handy.

Or, if we were to go the standard route and run wires for electric lights, anyone have a rough idea of the trenching and wire cost for approx 8200 feet of wiring? Located N of Houston, TX if that helps...
Click to expand...

Almost certainly batteries.
 
No experience with the runway lighting, but I have to imagine that a low voltage direct-wired setup would be far less-frustrating as time went by. Solar lights have batteries that will need to be replaced, and most of them aren't designed to be replaced easily. Running conduit/wiring is a pain and can be expensive on initial outlay, but it is likely less labor-intensive to maintain. If it were me, I'd go with LEDs and conduit.

As far as trenching it, you could just rent a ditch witch and do it yourself for a reasonable cost (less than $1K for a few days rental.) If you just want to run wire with no conduit, the make cable-install machines that can do it as long as you don't want it buried deeper than a foot or so.
 
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timwinters said:
As some of you who frequent purple may know, I have a piece of property under contract just outside of Conway, MO that will allow for a 2,000' strip. I'm starting to research runway light options and the possibility of going solar...solar would avoid a $2,500 expenditure for 5,000' of 12/2 direct burial wire before I even think about buying or making the fixtures themselves.

Two questions regarding this...

1. Does anyone have any 1st hand experience with solar lights that actually work and are durable? I gotta believe that the cheap walmart or harbor freight stuff would be a waste of (very little) money because they don't appear to be either durable or bright enough to see from the distances required for runway marker lights. My current design will require 30 lights.

2. The prevailing design of lit grass runways that I'm familiar with, is to install yellow cones like these:
View attachment 56989
at a 200' spacing with the lights mounted 1/2 way between the cones on frangible posts.

Why not just mount the lights on top of the cones?? It would be less to mow around and, if I decide to go hardwired, the direct burial wiring could be brought up to the light inside the cone eliminating all need for conduit. Am I missing something when considering this? (BTW...I already have 50 of these cones, more than enough for the runway and a windsock circle.)

Thanks in advance for any input.
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Tim has me on ignore, but there's a grass strip not far from there with lighting. It might be worth stopping in and seeing his setup.
 
We used solar runway lighting at a previous job. The lighting units themselves were insanely expensive but they worked pretty well. If I remember right we would get 6 hours or more out of a charge. They were remotely controlled so they weren't usually on continuously. When I left, we'd had them for about 4 years and they hadn't required any maintenance. They were used about 1 night a week.
 
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Ravioli said:
You are a member of a truly elite club!
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I'm blocked by Tim and followed by Wrbix, I can't figure that one out. :dunno: I'm pretty sure neither holds me in very high regard.
 
Thinking outloud...

I guess i've never really understood the concept of low voltage. Since Volts x Amps = Watts, thus for the same wattage lamp, a low voltage system requires higher amperage. And since amps are what drives wire size, the lower the voltage the bigger the wire. If I go hard wired, wire is going to be by far the biggest single cost.

120v LEDs providing 450 lumens (the equivalent of a 40w incandescent, which I'm confident will be visible at altitude) are only 6 watts. If I feed the runway from the middle (ish), that's only 15 lamps per side, or 90 watts, 3/4 of an amp at 120v.

Running these numbers thru a voltage drop calculator, #14 is adequate with well less than 5% drop at the end of the line. That saves me a bit of money from my original thinking...my original calcs included all 30 lamps and that would require #12 wire. #14 is about 33c/ft instead of 50c/ft like #12 is. So, the cost of 5,000' of wire drops to $1,650 instead of $2,500.

But the main run to the initial split would likely need to be #12. So if I figure 1,000' of #12 and 4,000' of #14...that's $1,820. I already have a Pilot Controlled Lighting box and I have a skidsteer and trencher so it's mostly a function of more time to go hardwired.

Vapor proof jelly jar lights like this:
jellyjar.png

can be had for less that $10. Add a $3 LED lamp, and misc hardware, mount them on top of the cones, and, all in, we're looking at less than $20/light. That's only $600. Add the wiring and we're at $2,500 total.

I think I can live with that unless better options for solar come along.

There is one company, flight lite, making GREAT solar runway lights.

AV310-AV410.jpg


They better be great for $1,000 each though!!! (and that's for the smaller one).
 
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Tim, congrats on getting a plot of land that you can build an airstrip on! As you know we're planning on the same at our homestead, although only 1,000 ft or so.

Dumb question, but what do you figure your need will be for runway lighting? i.e. how will you use it? How late will you be coming into the airport and how often? Is this just a "I got home a little later than normal" or "I'm coming home at 3 AM" kind of thing?

When we moved here we talked about getting enough land that we could build a strip long enough for the 310. We pretty much figured that even if we did that, I wouldn't land the plane there at night, so night lighting wouldn't be necessary.

It might be worth building the runway and flying out of it a bit, then adding the lighting later once you've spent some time on it.
 
timwinters said:
Thinking outloud...

I guess i've never really understood the concept of low voltage. Since Volts x Amps = Watts, thus for the same wattage lamp, a low voltage system requires higher amperage. And since amps are what drives wire size, the lower the voltage the bigger the wire. If I go hard wired, wire is going to be by far the biggest single cost.

120v LEDs providing 450 lumens (the equivalent of a 40w incandescent, which I'm confident will be visible at altitude) are only 6 watts. If I feed the runway from the middle (ish), that's only 15 lamps per side, or 72 watts, or less than 3/4 of an amp at 120v.

Running these numbers thru a voltage drop calculator, #14 is adequate with well less than 5% drop at the end of the line. That saves me a bit of money from my original thinking...my original calcs included all 30 lamps and that would require #12 wire. #14 is about 33c/ft instead of 50c/ft like #12 is. So, the cost of 5,000' of wire drops to $1,650 instead of $2,500.

But the main run to the initial split would likely need to be #12. So if I figure 1,000' of #12 and 4,000' of #14...that's $1,820. I already have a Pilot Controlled Lighting box and I have a skidsteer and trencher so it's mostly a function of more time to go hardwired.

Vapor proof jelly jar lights like this:
View attachment 56992

can be had for less that $10. Add a $3 LED lamp, and misc hardware, mount them on top of the cones, and, all in, we're looking at less than $20/light. That's only $600. Add the wiring and we're at $2,500 total.

I think I can live with that unless better options for solar come along.

There is one company, flight lite, making GREAT solar runway lights.

View attachment 56993


They better be great for $1,000 each though!!! (and that's for the smaller one).
Click to expand...
Low voltage DC system works for LEDs since they are DC devices. With pilot controlled lighting a couple batteries with a solar charger/maintainer would run a 24v LED system just fine.
 
Landing at night on a 2K turf strip sounds like a recipe for tragedy. Hope I'm wrong, Tim's good people.
 
Clark1961 said:
Low voltage DC system works for LEDs since they are DC devices. With pilot controlled lighting a couple batteries with a solar charger/maintainer would run a 24v LED system just fine.
Click to expand...

I was going to comment roughly the same thing, low-voltage DC is what we were suggesting, not AC.
 
Ted DuPuis said:
Dumb question, but what do you figure your need will be for runway lighting? i.e. how will you use it? How late will you be coming into the airport and how often? Is this just a "I got home a little later than normal" or "I'm coming home at 3 AM" kind of thing?
Click to expand...

Mostly, the getting home a bit later than normal part but, one never knows! In previous lives I had a need to do a moderate amount of night flying and, hell, my next adventure might call for it again...who knows!

steingar said:
Landing at night on a 2K turf strip sounds like a recipe for tragedy. Hope I'm wrong, Tim's good people.
Click to expand...

Yeah, it takes some getting used to...I used to fly in/out of a lighted 2800' grass strip. Almost never missed the turn to my hangar at night, it was middle, it was my goal to make it. I'd occasionally carry too much speed and miss it but not often. It's just a freakin' straight tail 182 afterall!!! ;)

Oh, and BTW, I won't be inviting many if any over to practice their night landings!

Clark1961 said:
Low voltage DC system works for LEDs since they are DC devices. With pilot controlled lighting a couple batteries with a solar charger/maintainer would run a 24v LED system just fine.
Click to expand...

I guess I have a mental block on this one Clark because I still don't understand. DC or AC, it's still v x a = w. I don't know how I could get by with less than 6w LEDs and see them at altitude. 15 lights would draw 3.75 amps at 24 volts and would require #2 wire to maintain less than 5% voltage drop. There's obviously something I'm not following here but I'm not a DC guy.
 
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timwinters said:
I guess I have a mental block on this one Clark because I still don't understand. DC or AC, it's still v x a = w. I don't know how I could get by with less than 6w LEDs and see them at altitude. 15 lights would draw 3.75 amps at 24 volts and would require #2 wire to maintain less than 5% voltage drop. There's obviously something I'm not following here but I'm not a DC guy.
Click to expand...

LEDs are constant current devices. As long as the voltage is above the cut off voltage for whatever power supply is in the LED module, it shouldn't matter.
 
timwinters said:
I guess I have a mental block on this one Clark because I still don't understand. DC or AC, it's still v x a = w. I don't know how I could get by with less than 6w LEDs and see them at altitude. 15 lights would draw 3.75 amps at 24 volts and would require #2 wire to maintain less than 5% voltage drop. There's obviously something I'm not following here but I'm not a DC guy.
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Maybe you’re missing the distance thing. The 3.75 amps aren’t traveling 1,000 feet.
 
Also, maybe solar could be made to work a little more cheaply and reliably by moving the cells to a couple of power stations off the runway, and then running wire from those boxes. You could have larger, deep cycle batteries that could stand up to the heat and load, larger panels, better positioning, etc.
 
Where I fly out of it looks like 60 watt light bulbs with an upside mason jar on top of each of them and seem to work just fine.

Maybe battery powered Christmas lights would do the trick
 
Or heating pads and thermal IR goggles.

(I think I read it in a Tom Clancy book, so must be true.)
 
timwinters said:
Mostly, the getting home a bit later than normal part but, one never knows! In previous lives I had a need to do a moderate amount of night flying and, hell, my next adventure might call for it again...who knows!
Click to expand...

My thought then is that you do a wired system that you can control remotely, or at least set up on a timer or light sensor so that it automatically goes on at dusk and off again at dawn. It would suck to put a system in (solar) that's easier now but then you find out won't do the job.
 
timwinters said:
I guess i've never really understood the concept of low voltage. Since Volts x Amps = Watts, thus for the same wattage lamp, a low voltage system requires higher amperage. And since amps are what drives wire size, the lower the voltage the bigger the wire. If I go hard wired, wire is going to be by far the biggest single cost.
Click to expand...
Low voltage = cheap ass insulated wire that you can direct bury just a couple inches below the surface, and no ground wire.
High voltage = Two wire with ground cable rated for direct burial at a much deeper depth or you pull it through conduit that also has to be at some depth or another.
 
Cooter said:
I'm blocked by Tim and followed by Wrbix, I can't figure that one out. :dunno: I'm pretty sure neither holds me in very high regard.
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I can't figure that out either......but don't dwell on it. :rolleyes:
 
Capt. Geoffrey Thorpe said:
Low voltage = cheap ass insulated wire that you can direct bury just a couple inches below the surface, and no ground wire.
High voltage = Two wire with ground cable rated for direct burial at a much deeper depth or you pull it through conduit that also has to be at some depth or another.
Click to expand...

Where I live wire in conduit (Sch 40 PVC or galvanized rigid pipe) must be 18" below grade. Direct burial cable must be 24" below grade. I think that's National Electric Code and so should be at least that deep anywhere in the US.

John
 
I think you need to decide between 120V, 240V or DC (Battery Voltage). Keep in mind there is about a mile limit (anyway some kind of limit) on the voltage drop for 120V and more distance allowed for 240V. Aircraft Spruce has some of both. Unless you want someone to turn on each light individually, you are going to have to run a wire. You might get away with just one side. Depends on how good you are at bouncing at night :).
 
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NM went through a time when they were installing 'retroreflective' markers on a bunch of their runways, I wondered how that turned out.
Coincidentally, a pvt rwy I use is about to get some.

Hey, when they upgraded our lights here, they threw the old ones behind my hangar - maybe you could buy em
 
Mistake Not... said:
LEDs are constant current devices. As long as the voltage is above the cut off voltage for whatever power supply is in the LED module, it shouldn't matter.
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Okay, but again, since v x a = w wouldn't that mean that as the voltage drops and the current (amps) remains constant, then the wattage drops? i.e. the light output drops?

Clark1961 said:
Maybe you’re missing the distance thing. The 3.75 amps aren’t traveling 1,000 feet.
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No, I get that, I was just using that as an example. But the wire would still be really hefty unless I'm missing something, which is quite possible.
Capt. Geoffrey Thorpe said:
Low voltage = cheap ass insulated wire that you can direct bury just a couple inches below the surface, and no ground wire.
High voltage = Two wire with ground cable rated for direct burial at a much deeper depth or you pull it through conduit that also has to be at some depth or another.
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Sure, for a few cheap lamps around your yard that aren't providing much light in the first place, but does this hold true for 30 lamps on a runway that have to be seen from 1000 feet? Dunno, just askin'.

Gotta love this thread, typical PoA. We've discussed all sorts of things, except the two questions I posed.
 
Tim, usually the way LEDs are driven is with a "constant current driver". This is an active component that requires a voltage above a certain level (usually a fixed amount above the Vf of the LED), and then "does whatever it has to" to keep a constant current through the LED. So, for example, let's say you have an LED requiring 500ma. The constant current driver may require 8V-36V. Feed it anything in that range, and the LED will "see" a constant 500ma. That's why I said the voltage doesn't matter. Yes, you'll get a voltage drop along the line... but as long as the last light still has at least, say, 8V, the driver can make it the same brightness as every other LED.

I don't know if it helps or not, but an LED is a diode. Once the diode starts to conduct, the voltage drop across the diode remains constant, regardless of the input voltage. The -current- increases fast, though, with increasing voltage. That's why you need a constant -current- driver, not a constant -voltage- driver. The led driver in this instance is a "buck" converter that uses the excess voltage to create current. As long as it has enough V above a certain minimum, it can feed the LED a constant I and everyone's happy.

That said, I've never designed anything like this. In miniature, sure, but before I'd commit this kind of money, I'd find someone who has run 1000ft of wire for something and had it work. :) OTOH, if I were doing it, I'd love the project. Sounds like fun. I'd probably make each light individually controllable so I could have that Battlestar Galactica docking bay effect. Or maybe blink the pair for the desired touch down point, or have them light the abort point for take off, or... All controlled from a tablet app, of course. lol
 
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Mistake Not... said:
...OTOH, if I were doing it, I'd love the project. Sounds like fun. I'd probably make each light individually controllable so I could have that Battlestar Galactica docking bay effect. Or maybe blink the pair for the desired touch down point, or have them light the abort point for take off, or... All controlled from a tablet app, of course. lol
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Yep, I can see it now. A whole separate page and menu on the Garmin 1000 (or its Foreflight equivalent) just to operate all the options for the runway lights. :D

There should be a color selection module. Red and green for Christmas, orange for Halloween, pink for your daughter's birthday, red/white/blue for the 4rth, that sort of thing? :rolleyes:
 
Solar is going to be regular maintenance. Wired will be a one time pain in the butt, with little follow up work. Batteries go bad, panels get dirty, the electronics fail, the more of them you have, the more likely one will be inop at any given time.
 
Mistake Not... said:
Tim, usually the way LEDs are driven is with a "constant current driver". This is an active component that requires a voltage above a certain level (usually a fixed amount above the Vf of the LED), and then "does whatever it has to" to keep a constant current through the LED. So, for example, let's say you have an LED requiring 500ma. The constant current driver may require 8V-36V. Feed it anything in that range, and the LED will "see" a constant 500ma. That's why I said the voltage doesn't matter. Yes, you'll get a voltage drop along the line... but as long as the last light still has at least, say, 8V, the driver can make it the same brightness as every other LED.

I don't know if it helps or not, but an LED is a diode. Once the diode starts to conduct, the voltage drop across the diode remains constant, regardless of the input voltage. The -current- increases fast, though, with increasing voltage. That's why you need a constant -current- driver, not a constant -voltage- driver. The led driver in this instance is a "buck" converter that uses the excess voltage to create current. As long as it has enough V above a certain minimum, it can feed the LED a constant I and everyone's happy.

That said, I've never designed anything like this. In miniature, sure, but before I'd commit this kind of money, I'd find someone who has run 1000ft of wire for something and had it work. :) OTOH, if I were doing it, I'd love the project. Sounds like fun. I'd probably make each light individually controllable so I could have that Battlestar Galactica docking bay effect. Or maybe blink the pair for the desired touch down point, or have them light the abort point for take off, or... All controlled from a tablet app, of course. lol
Click to expand...

That helps immensely, thanks!
 
7B3 has some very good solar runway lights that are turning on via radio. No wires needed. They used to have the lights on top of the yellow cones, but you can't see those at night. Or barely can. These new ones work very well. I don't know the brand, but can snag a picture some time this week. They all have batteries, and are on a network (bluetooth) so one controls them all. They aren't cheap.
 
The resistance of the wire itself causes a voltage drop on long runs. Higher voltage has less drop per distance.
 
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timwinters said:
120v LEDs...
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There is no such thing. Think about it. Diode. What does a diode do? (Even if it produces light while it does it?) Current only flows one way through a diode. (Until you hit reverse breakdown voltage, but let’s ignore that for a minute.)

A diode will make DC if fed with AC. :)

A “120V LED” is marketing wank for, “We put a current limiting device, maybe a voltage regulator, and a light emitting diode in the same package.”

Mistake Not... said:
Tim, usually the way LEDs are driven is with a "constant current driver".
Click to expand...

This. Perfect answer.

The absolute simplest circuit to drive LEDs is just DC within the voltage range of the LED, applied to a bunch of LEDs in series and the calculation done to match those with a single current limiting resistor. But there’s a voltage drop across each diode so there’s a limit to how many can be in series before you fall out of the diodes’ happy voltage range.

Obviously you want something a wee bit smarter than that when driving a bunch of runway lights. Putting them all on a string means if one fails, they all go out like old school Christmas light strings.

If you look carefully at LED strip lights they’re usually just a DC power supply, and two conductors running current to each LED on a “rail” and each little LED has a little surface mount resistor in series with it and that resistor is tied to the ground conductor. Often a few LEDs share a resistor.

You get the idea. That explains the D part of LED.

Like Da Man says, usually the current limiting devices are ultra cheap and are just packaged with the LED “light” in the base or wherever. In household AC powered LED “bulbs” most of the heat comes from the circuitry they stuff in the base that drops the voltage down from household AC to something the LED won’t fry at, and limits the current the LED (actually an array of LEDs in most “bulbs”) is allowed to pull. Really cheap (dangerous) crap just uses a “capacitive dropper” circuit which is simple and ultra cheap. Better quality stuff uses an active component (read: chip) to do the current limiting.

Anywhoo...

Back to your 2000’ runway.

The voltage drop due to wire resistance at 2000’ at DC is going to be huge unless you have a very large gauge of wire. Economically not feasible.

To go 2000’ or more from one end of your circuit to the other without a huge amount of resistance from heating the buried wire you’ll likely need that circuit to be AC. Higher voltage, lower resistance, yards yadda. Then tap each light off of that as you go and the only DC will be inside of each lamp assembly.

http://www.phy6.org/Electric/-E11-reason.htm

I’d have to do the math to see what your voltage drop would look like at 2000’ with buried AC “120V” single phase but you’re still pushing it at that distance, even with 12 ga wire.

Play with this calculator:

http://www.calculator.net/voltage-d...e=2000&distanceunit=feet&amperes=1&x=105&y=17

As you can see, even a 1A load by itself at the end of 2000’ of 12 ga at 120V AC single phase, is 5.29% loss at the other end. Most sparkies shoot for 3% or less. And you have little loads distributed all along that 2000’, plus connector losses.

Would some “AC LED bulbs” work at 113V at the far end, probably. But it’d be lower than that with the bulbs in the middle of the string drawing current also. And remember that’s a 1A total load I calculated for. Your Amperage May Vary. ;)

I think another bigger problem with buried wiring and AC or DC, whatever you choose, is going to be lightning and grounding protection. One nearby lightning strike, and a simple LED setup like you see in most garden low-voltage DC lighting is going to pop all of them without being designed for outdoor use and having overvoltage shunt-to-ground protection built into each lamp assembly.

There ya go. Food for thought. I’m not a sparky, but I play one on TV.

Consult a real electrician, YMMV, IANAE, and other standard disclaimers.
 
Short version for the AvE fans:

2000 non-metrique feet is a long way to make angry pixies march. It probably won’t chooch.
 
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