Done With LED Nav Lights

[GeeBee]

I had a burnt out nav bulb so I figured what the heck? I replaced both with some Whelen Chroma LED lamps. It seemed a no brainer. I don't like the OR6502 series for one reason. This line in the ICA: 

If any one LED fails, the unit must be repaired or replaced. Replace the entire unit for one dead LED? Really? How about a few extra so you can have one or two out? 

With the Chroma, I can simply replace the bulb unit. Knowing that I had to either put in a relay or leave in one incandescent bulb in the circuit to prevent daytime dimming of the annunciator panel, I left the right aft white nav light incandescent for the time being. The install went good, it all worked. Then I was preparing to leave KMTN the other night and none of my LED nav lights worked. No green, no red, no white on the left aft..Only the incandescent worked. I fortunately kept my incandescent bulbs, so I changed them on the ramp. Took about 45 minutes but I got them all done and everything was ops normal. I flew home to Georgia that night. Today I tried the LED's again. Tried them one at a time.  I tried an improved ground. No help, so I am back to incandescent. Don't know if I will try the OR6502 because of the ICA limitation.

 

[MB65E]

I hear you! Just lost my green chroma. 
2nd one that has burnt out. 
I Might go back to the old lamps for good!! 
-Matt

[N201MKTurbo]

I haven’t gotten on the LED nav light bandwagon. I still have incandescent bulbs. In 40 years of airplane ownership, I think I have replaced 3 nav light bulbs. I fail to see what problem LED nav lights are solving.

[LANCECASPER]

51 minutes ago, N201MKTurbo said:

I fail to see what problem LED nav lights are solving.

Whelen's bottom line 

The challenge comes in when the power supply box for the strobes fails. Since the nav and strobe lights are together on the wing tip, if the strobe box goes out people find it's better to bite the bullet and switch to the LED strobe/nav.

Mooney made a smart manufacturing move to simplify when on later models (maybe only Acclaim) they mounted the strobe power unit on the backside of the baggage compartment in the avionics bay, rather than mounting a unit in each wing. It makes wiring and syncing a breeze when you eliminate the power supply and switch to LED units. 

[Rwsavory]

Aeroled Polaris is a less expensive alternative to Chroma nav lights. Installed about 200 hours ago and leave them on continuously. No problems. 

[GeeBee]

I think the problem with LED conversion comes when you add in the dimming feature of the annunciator panel which is tied to the nav lights. It would be easy to blame the Whelen Chroma LEDs but the Aero-Lites white nav LED also went down. So the problem is in the circuit design, not the lights themselves. I am sure it can be overcome, but seems to be a lot of hassle.

 

[MB65E]

17 minutes ago, GeeBee said:

I think the problem with LED conversion comes when you add in the dimming feature of the annunciator panel which is tied to the nav lights. It would be easy to blame the Whelen Chroma LEDs but the Aero-Lites white nav LED also went down. So the problem is in the circuit design, not the lights themselves. I am sure it can be overcome, but seems to be a lot of hassle.

 

I disagree. Mine are not on a dimmer. Lost a green one on a 182 I work on as well as our M20E. Might try aeroLED, thanks. The green LED coloring is so awesome! 
-Matt

[GeeBee]

9 minutes ago, MB65E said:

I disagree. Mine are not on a dimmer. Lost a green one on a 182 I work on as well as our M20E. Might try aeroLED, thanks. The green LED coloring is so awesome! 
-Matt

I think you misunderstand. Without the return through ground that a filament provides the annunciator panel is automatically dimmed and unreadable in daylight. No LED can provide that return by its very nature as a diode. 

[EricJ]

2 hours ago, GeeBee said:

I think you misunderstand. Without the return through ground that a filament provides the annunciator panel is automatically dimmed and unreadable in daylight. No LED can provide that return by its very nature as a diode. 

A diode, including LEDs, conducts current when it's On just like a filament does.   It doesn't conduct as much, though, since it uses much less power to produce the same amount of light.   A filament stops conducting when it fails, and there are similar failure modes for LEDs.   The main difference is the amount of current used when On.

[Ragsf15e]

I’ve had aeroLEDs on mine for at least 9 years too (previous owner).  One leaked and filled with water (still working).  One (white tail light) went out. Both were replaced free even though I had no warranty info, proof of purchase, etc. In the last 8 years, I leave them on and no issues.

[Marc_B]

Wouldn't this be purely just due to the FAA process of certification?  i.e. because these are STC/TSO'd that Whelen would have had to undergo certification for each decrease in LED bulbs in order to maintain the STC/TSO without having to specify that failure of a light requires repair?  Out of curiosity, has anyone had a bulb fail; if so how long in service and what was the cost to repair?  I think the standard WAT warranty is 5 years from purchase...so within that time I'd expect warranty repair.

[PT20J]

47 minutes ago, EricJ said:

A diode, including LEDs, conducts current when it's On just like a filament does.   It doesn't conduct as much, though, since it uses much less power to produce the same amount of light.   A filament stops conducting when it fails, and there are similar failure modes for LEDs.   The main difference is the amount of current used when On.

The dimming circuit depends on the filament of an incandescent bulb having a very low resistance when the bulb is not powered. The landing gear annunciator light is grounded through a 470 ohm resistor and also through a diode to the nav light circuit. When the nav lights are powered, the diode is reverse biased and the 470 ohm resistor limits the current and dims the annunciator bulb. When the nav lights are off, the filament(s) provide(s) a low resistance path to ground through the diode shunting the 470 ohm resistor and allowing more current through the annunciator light bulb causing to burn brighter. The annunciator bulb draws much less current than the nav light bulbs so that even though current is flowing through the nav lights, they don't illuminate. It is a circuit design that is just maybe a little too clever .

[A64Pilot]

6 hours ago, N201MKTurbo said:

I haven’t gotten on the LED nav light bandwagon. I still have incandescent bulbs. In 40 years of airplane ownership, I think I have replaced 3 nav light bulbs. I fail to see what problem LED nav lights are solving.

I’m with you. As I have a tailbeacon, the lights are on all of the time, and I guess it’s three years later they still work.

However I think that new aircraft should be all LED, and good quality LED’s will last a very long time, but to spend the $$ that they cost to replace the old incandescent?

You just don’t get anything for the money from what I can see. 

Low quality LED’s are noisy, so noisy that they can interfere with Comm / Nav equipment. I put inexpensive LED lights in my hangar, they are so noisy that they break squelch on my radios. So if you buy LED’s from Ebay, Amazon or whatever they could cause a problem. The USCG check procedure only checked Comm freqs of course not AIS etc. 

[N201MKTurbo]

It is very unlikely the LED devices are failing. It is almost certainly the mounting and control circuitry assembly is failing. 
 

Like most PCB assemblies, Heat and vibration are the problem. And don’t forget water, which can get in and corrode the circuitry.

The LED light assemblies are much more complex than an incandescent bulb. And therefore have more failure modes. 

[MikeOH]

I, too, would bet on mounting of the LEDs as the problem. Solder attach of large surface mount components (high-output LEDs, in this case) for long term reliability is difficult to do properly.  Environmental and operational thermal cycling of the solder joints combined with the TCE mismatch between the LED and the substrate (circuit board) commonly results in solder joint fatigue  failures over relatively short times if not well engineered.

[Will.iam]

13 hours ago, LANCECASPER said:

Whelen's bottom line 

The challenge comes in when the power supply box for the strobes fails. Since the nav and strobe lights are together on the wing tip, if the strobe box goes out people find it's better to bite the bullet and switch to the LED strobe/nav.

Mooney made a smart manufacturing move to simplify when on later models (maybe only Acclaim) they mounted the strobe power unit on the backside of the baggage compartment in the avionics bay, rather than mounting a unit in each wing. It makes wiring and syncing a breeze when you eliminate the power supply and switch to LED units. 

Yep this is what prompted me to switch. One of my strobe power supply boxes quit working and the price to replace one was the same as one led light strobe combo and the other strobe box has the same years of use so likely to fail soon too so just replace both get 3 lbs of useful load back and brighter nav lights with minuscule current draw.  

[Pinecone]

FYI, if anyone needs strobe boxes, mine are for sale.  Ad in the Classified section.
 

[Mark89114]

21 minutes ago, Pinecone said:

FYI, if anyone needs strobe boxes, mine are for sale.  Ad in the Classified section.
 

I should probably buy a spare.....I refuse to pay what they are charging for LED's.

 

My previous plane a C-152 I carried around spare nav and landing lights for nearly 20 years.....didn't use a damn one of them.

[LANCECASPER]

41 minutes ago, Mark89114 said:

I should probably buy a spare.....I refuse to pay what they are charging for LED's.

 

My previous plane a C-152 I carried around spare nav and landing lights for nearly 20 years.....didn't use a damn one of them.

LEDs seem much more reasonable when you price the power supply for the legacy strobes ($925). https://www.aircraftspruce.com/catalog/elpages/whelenpowersupplies.php

This box powers both strobes now, but still it will fail eventually. The boxes seem to have about a 15-20 year life.

The flash tubes are $240 each and you have one on each wing plus one on the tail. https://www.aircraftspruce.com/catalog/pnpages/11-03250.php

if you know beforehand that what the cost of doing it once is (roughly $1500-$1600 for both wings and tail) -  it makes it less frustrating than $240 here and there and $900+ for the power supply, nav bulbs, etc. I had it finished in an afternoon. 

My power supply, the one mentioned above was still working perfectly. That box, which is on newer Mooneys, controls both strobes and is now in the avionics bay not the wing. I sold it on Beechtalk for $500, so my net cost was +/- $1000-$1100. 

 

[Jim Peace]

10 hours ago, Mark89114 said:

I should probably buy a spare.....I refuse to pay what they are charging for LED's.

 

My previous plane a C-152 I carried around spare nav and landing lights for nearly 20 years.....didn't use a damn one of them.

Mine, LED are on 100% of the time I fly.....did you have them on in the 152 100% of the time?....see and be seen....and LEDs really make you be seen...

[Jim Peace]

https://www.aveoengineering.com

Cant say enough good things about this company....I was just in their Florida office today talking to them...

Pricey...YES but you get great customer service. and the lights look great...

Incandescent lights are cheaper but you cant be seen as well as having LED's...

Installers are the main problem with LEDs....if they are dropped or over torqued the lens will crack and moisture gets in...then it's all down hill from there.  Occasionally one will fail like mine did recently for no reason at all....but it was replaced under warrantee....

[GeeBee]

1 hour ago, Jim Peace said:

https://www.aveoengineering.com

Cant say enough good things about this company....I was just in their Florida office today talking to them...

Pricey...YES but you get great customer service. and the lights look great...

Incandescent lights are cheaper but you cant be seen as well as having LED's...

Installers are the main problem with LEDs....if they are dropped or over torqued the lens will crack and moisture gets in...then it's all down hill from there.  Occasionally one will fail like mine did recently for no reason at all....but it was replaced under warrantee....

So why is the M20S the only long body approved?

[Jim Peace]

2 hours ago, GeeBee said:

So why is the M20S the only long body approved?

No idea. I own a C and those tips are not on my radar.