Tail light on M20J

[JayMatt]

So My 78 M20J have a regular bulb light in the rudder. There are only 2 wires going to it. I was looking at replacing it when I get done painting. Watt seems to only have a position light and an anti collision light with the LED version. Is it hard to run the additional wire to include anti collision? My A&P/I lets me do everything I want, Just trying to figure out how much of a hassle it is. 

[N201MKTurbo]

Why don't you wait till the light burns out.

With the LED light, just don't hook up the strobe wire.

The wire runs through the rudder, through the gap between the ruder and fuselage with a quick disconnect there, then through the tail cone and along the left side of the cabin. I would wait till annual when the plane is opened up if you want to run a new wire.

It would be a good idea to check the rudder balance after install.

I don't understand why everyone wants to replace all their position lights with LEDs. They don't draw that much current and in the last 39 years of airplane ownership I have replaced two bulbs. The cost of those two bulbs is less than one LED light by a lot. 

I guess it is the same reason people put chrome lug nuts on their old trucks...

[rickseeman]

LED's are sexy. I want them and I don't even fly at night.

[N201MKTurbo]

35 minutes ago, rickseeman said:

LED's are sexy. I want them and I don't even fly at night.

I bought my wife diamond earrings last Christmas. I guess it is the same thing.

[atpdave]

1 hour ago, N201MKTurbo said:

[…]

I don't understand why everyone wants to replace all their position lights with LEDs. […]

I replaced mine when the strobe power supply quit. Whelen used to repair them relatively inexpensively but they don’t anymore. LEDs weren’t much more expensive than a new power supply, and I wasn’t going to go back with old technology. I ran new tail wiring essentially as you had described and had it inspected and signed off, probably saved a few hours labor charge for that.

[MisfitSELF]

I guess you can get rid of that 1 pound brick in the aft fuselage that powers the light/strobe with the led.  Once I have that light (or any of my nav/position/strobes for that matter) burn out I'm replacing them with LEDs and saving a whole 3 pounds.  I keep waiting -- it's been 5 years since I bought the aircraft -- I'm still waiting.

However, I keep telling people that if weight savings was the goal, it'll be cheaper to get lipo.

 

Bruce 

[Ryan ORL]

Do be aware that there is a possibility that this will affect the auto-dimming function of your GEAR DOWN annunciator light.  Somewhat strangely, this circuit is tied to the Nav light circuit, and the 'normal' tail bulb (at least in my 84 J) is also part of that circuit.

I have LED Nav Lights in my wingtips, but I have left the tail light as-is for now.  Reason being that having at least one of the lights be a standard incandescent avoids the issue.

The dimming annunciator thing can be solved, but requires a little minor modification with some relays or something.  You can search the details on here somewhere.

[ArtVandelay]

LED lights stand out among the backdrop of ground clutter, they’re safer, common for others to see long before I see them.
I’m all LEDs, got lots of compliments back when they were more rare.

[A64Pilot]

Anyone that has the ADSB in their taillight has to fly with the Nav lights on all of the time.

Seems the bulbs still last for years, and while I know there is a workaround for installing LED’s and keeping the gear down dimming function, I just can’t understand why go through all of the trouble, plus your modifying a warning system light, and I’m not so sure I’d win the argument that’s a minor modification, depends on who your arguing with I guess and if your trying to defend yourself after a gear up landing.

If your going to a tail strobe, then I guess it’s worth it, as they do improve visibility 

But I think I’d be tempted to add a light by the battery that’s easily replaced and keeps me from modifying the landing gear down light system

[mhrivnak]

The hardest part may be snaking the wire through the tail section aft of the quick disconnect. Assuming you have the rudder off right now, since you say you're going to "get done painting", that makes it a lot easier. And if you install an LED light now, you can include the new fixture when you balance the rudder (assuming you're painting the rudder and planning to balance it anyway).

If you're going to run wire, run two so you'll have a sync wire available to tie into your other strobes. I don't know if it's compatible with your existing wing strobes, but even if not, if you go all-LED in the future, you'll be happy to have that sync wire ready!

[jaylw314]

1 hour ago, mhrivnak said:

The hardest part may be snaking the wire through the tail section aft of the quick disconnect. Assuming you have the rudder off right now, since you say you're going to "get done painting", that makes it a lot easier. And if you install an LED light now, you can include the new fixture when you balance the rudder (assuming you're painting the rudder and planning to balance it anyway).

If you're going to run wire, run two so you'll have a sync wire available to tie into your other strobes. I don't know if it's compatible with your existing wing strobes, but even if not, if you go all-LED in the future, you'll be happy to have that sync wire ready!

Does anyone know of any studies that examined whether synced strobes were more visible than unsynced strobes?  I mean, I intuitively thought synced strobes would be better, since you have a VERY bright on for a shorter time, but then I realized a lot of planes now have strobes with multiple flashes, with dimmer flashes spread out over multiple pulses.

FWIW, I don't have mine synced, I was just too cheap to run the sync wire  

[Aerodon]

On 1/11/2023 at 7:55 AM, MisfitSELF said:

I guess you can get rid of that 1 pound brick in the aft fuselage that powers the light/strobe with the led.  Once I have that light (or any of my nav/position/strobes for that matter) burn out I'm replacing them with LEDs and saving a whole 3 pounds.  I keep waiting -- it's been 5 years since I bought the aircraft -- I'm still waiting.

However, I keep telling people that if weight savings was the goal, it'll be cheaper to get lipo.

 

Bruce 

Yes, I took the 1lb brick out of the tail and then promptly added 11 lb's of Charley weights at the same location.

I replaced the wingtips with Ave's, and had to add a combined strobe / aft nav light anyway.

 

Aerodon

[ArtVandelay]

Does anyone know of any studies that examined whether synced strobes were more visible than unsynced strobes?  I mean, I intuitively thought synced strobes would be better, since you have a VERY bright on for a shorter time, but then I realized a lot of planes now have strobes with multiple flashes, with dimmer flashes spread out over multiple pulses.
FWIW, I don't have mine synced, I was just too cheap to run the sync wire  

I prefer the twinkling effect of them not being in synced.

[PT20J]

41 minutes ago, jaylw314 said:

Does anyone know of any studies that examined whether synced strobes were more visible than unsynced strobes?  I mean, I intuitively thought synced strobes would be better, since you have a VERY bright on for a shorter time, but then I realized a lot of planes now have strobes with multiple flashes, with dimmer flashes spread out over multiple pulses.

FWIW, I don't have mine synced, I was just too cheap to run the sync wire  

I don’t know. But I’ve noticed several tall TV towers (1000’ to 2000’) that have synched strobes and it makes them very visible even in daylight.

[Aerodon]

3 hours ago, PT20J said:

I don’t know. But I’ve noticed several tall TV towers (1000’ to 2000’) that have synched strobes and it makes them very visible even in daylight.

I think it is more important to sync the wingtips than the tail?

Aerodon

[PT20J]

25 minutes ago, Aerodon said:

I think it is more important to sync the wingtips than the tail?

Aerodon

Probably depends on the viewing angle

[0TreeLemur]

 

52 minutes ago, Aerodon said:

I think it is more important to sync the wingtips than the tail?

Aerodon

In a J at least, the tips and tail are not often visible at the same time.   I'd say let the tail flash however it wants.  Sync the wingtip strobes for better visibility head-on.

[Fly Boomer]

10 hours ago, jaylw314 said:

Does anyone know of any studies that examined whether synced strobes were more visible than unsynced strobes?  I mean, I intuitively thought synced strobes would be better, since you have a VERY bright on for a shorter time, but then I realized a lot of planes now have strobes with multiple flashes, with dimmer flashes spread out over multiple pulses.

FWIW, I don't have mine synced, I was just too cheap to run the sync wire  

Not sure if you are talking LEDs or xenon strobes, but I have read that the factory Whelen strobes, when synchronized, pump out less juice to each strobe.  Probably still brighter than LED.

[Guest]

The stored energy in the capacitor is shared on two strobes in synchronized mode, versus delivered to one strobe at a time, so in theory synchronized mode should deliver lower light output.

[ArtVandelay]

 
Sync the wingtip strobes for better visibility head-on.

I don’t see why.

[Fly Boomer]

1 minute ago, ArtVandelay said:

I don’t see why.

One possibility is that the light appears to be emitted from something 36 feet wide instead of a point source.  The subtended angle is huge compared to the apparently point source.

[0TreeLemur]

1 hour ago, Fly Boomer said:

One possibility is that the light appears to be emitted from something 36 feet wide instead of a point source.  The subtended angle is huge compared to the apparently point source.

Exactamundo.

[ArtVandelay]

One possibility is that the light appears to be emitted from something 36 feet wide instead of a point source.  The subtended angle is huge compared to the apparently point source.

In either case you have 2 sources. It would be interesting to test how the human eye/brain reacts to one vs the other.
In my case I have recognition lights (wigwag) in addition to 2 pairs of LED taxi/landing lights, if you don’t see me, you’re not looking.

[Pinecone]

For recog lights, the question is, wig wag between the two, or both recog wig wagged with an landing/taxi (cowl mounted)?

I am sure that there has been research done on this.

[ArtVandelay]

For recog lights, the question is, wig wag between the two, or both recog wig wagged with an landing/taxi (cowl mounted)?
I am sure that there has been research done on this.

I wigwag only the recognition lights, I left the wing taxi/landing lights alone because they still be needed for taxiing and landing. And how many blinking lights do you need?