Taxi Light Orientation (Update)

[GeeBee]

The previous owner installed Whelen Prometheus Pro LED landing and taxi lights on my airplane. I note that the taxi light has a lens that with ridges on it. The current orientation of the ridges is horizontal. I was dis-satisfied with the performance I was going to check and align per the MM. However, I note all the pictures on the Whelen site show the lines vertical, not horizontal. I checked the Whelen install instructions and they make no mention of orientation. So the question is are the ridges supposed to be vertical or horizontal? 

 

[carusoam]

I could guess... or i could invite the Whelen guy... @OSUAV8TER (tech question, lens alignment during installation)

Best regards,

-a-

[PT20J]

I'd have to look at mine to see which way the lines run. But there is an alignment key on the bulb just like the GE bulbs that should fix the orientation.

FWIW, I don't think my Prometheus Plus taxi lights are all that great. The beam is so dispersed that it doesn't light up much more than a few feet ahead of the airplane. Sounds like the Pros might not be much better. When I put the landing and taxi lights in the wings, I did align them per the manual.

Skip

EDIT: I just looked on Whelen's website and I don't see a Pro taxi light. Are you sure you don't have a Plus?

[ArtVandelay]

I agree with Skip, if I had to do it over again, I would have installed landing lights and just aim them downward, assuming I can individually aim the lights.
BTW, for those with wing mounted lights, if you want a inexpensive speed mod, remove the clunky bracket:



As they did with later years:

[OSUAV8TER]

  On 2/26/2021 at 1:16 AM, GeeBee said:

The previous owner installed Whelen Prometheus Pro LED landing and taxi lights on my airplane. I note that the taxi light has a lens that with ridges on it. The current orientation of the ridges is horizontal. I was dis-satisfied with the performance I was going to check and align per the MM. However, I note all the pictures on the Whelen site show the lines vertical, not horizontal. I checked the Whelen install instructions and they make no mention of orientation. So the question is are the ridges supposed to be vertical or horizontal? 

 

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Per the installation manual "For a Taxi light, the 'lines' of the inner optic should be orientated vertically to produce a horizontal light beam."

ParmetheusPlus.pdfFetching info...

[OSUAV8TER]

  On 2/26/2021 at 3:27 AM, PT20J said:

I'd have to look at mine to see which way the lines run. But there is an alignment key on the bulb just like the GE bulbs that should fix the orientation.

FWIW, I don't think my Prometheus Plus taxi lights are all that great. The beam is so dispersed that it doesn't light up much more than a few feet ahead of the airplane. Sounds like the Pros might not be much better. When I put the landing and taxi lights in the wings, I did align them per the manual.

Skip

EDIT: I just looked on Whelen's website and I don't see a Pro taxi light. Are you sure you don't have a Plus?

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There is no Pro taxi light. The taxi light is only available on the PAR-36 Parmetheus Plus.

Generally speaking, any LED landing light will have a lens that projects the light pretty far, which results in a narrow pencil like beam. Factor in where they are mounting and the orientation of the installation, they might not make good taxi lights.

[GeeBee]

  On 2/26/2021 at 2:51 PM, OSUAV8TER said:

There is no Pro taxi light. The taxi light is only available on the PAR-36 Parmetheus Plus.

Generally speaking, any LED landing light will have a lens that projects the light pretty far, which results in a narrow pencil like beam. Factor in where they are mounting and the orientation of the installation, they might not make good taxi lights.

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Thank you for the clarification and why I could not find install instruction as the log book entry claimed it was a "Pro" which obviously, it is not. I am thinking of maybe just moving the Plus landing light to the taxi position, maybe aim it down a bit and get a Pro and install it in the landing position. I think that would be a better set up.

 

 

[PT20J]

  On 2/26/2021 at 3:34 PM, GeeBee said:

Thank you for the clarification and why I could not find install instruction as the log book entry claimed it was a "Pro" which obviously, it is not. I am thinking of maybe just moving the Plus landing light to the taxi position, maybe aim it down a bit and get a Pro and install it in the landing position. I think that would be a better set up.

 

 

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What I do is turn on both landing and taxi lights if it's dark and I'm not going to blind anyone. The landing lights shine farther ahead so I can see any obstructions in time to avoid them and the taxi lights fill in the area close by. I may replace the landing lights with pros at some point. The pluses are a bit disappointing and I don't see how anyone would have been pleased with the first generation Prometheus.

Skip

[OSUAV8TER]

  On 2/26/2021 at 5:45 PM, PT20J said:

What I do is turn on both landing and taxi lights if it's dark and I'm not going to blind anyone. The landing lights shine farther ahead so I can see any obstructions in time to avoid them and the taxi lights fill in the area close by. I may replace the landing lights with pros at some point. The pluses are a bit disappointing and I don't see how anyone would have been pleased with the first generation Prometheus.

Skip

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LED technology for aircraft has come a long quite a bit since they were first put into aircraft 10-15 years ago. The first generation LED lights are nothing to write home about. 

[OSUAV8TER]

  On 2/26/2021 at 3:34 PM, GeeBee said:

Thank you for the clarification and why I could not find install instruction as the log book entry claimed it was a "Pro" which obviously, it is not. I am thinking of maybe just moving the Plus landing light to the taxi position, maybe aim it down a bit and get a Pro and install it in the landing position. I think that would be a better set up.

 

 

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If you want the Pro, it is about twice as bright as the Plus, email me at gallagheraviationllc@gmail.com or visit my website at https://www.gallagheraviationllc.com/whelen-aircraft-lighting.html. They are $499.99 with no sales tax.

[GeeBee]

Sounds good! Thanks

 

[ZuluZulu]

  On 2/26/2021 at 9:13 PM, OSUAV8TER said:

If you want the Pro, it is about twice as bright as the Plus, email me at gallagheraviationllc@gmail.com or visit my website at https://www.gallagheraviationllc.com/whelen-aircraft-lighting.html. They are $499.99 with no sales tax.

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I have them, from James too.  I've certainly never struggled to see since putting them in!

[ArtVandelay]

  On 2/26/2021 at 5:45 PM, PT20J said:

The pluses are a bit disappointing and I don't see how anyone would have been pleased with the first generation Prometheus.
Skip

Remember when we had the incandescent bulbs? The first generation was leaps and bounds better. I have the the first generation, I bought them at a discount when pluses came out, with 4 lights it gets expensive fast. I can see fine, maybe when I get older I will need brighter lights. If I do, I’ll replace the taxi lights with the old Prometheus and put new generation of LEDs as landing lights.

[GeeBee]

Just came back from the airport and looked at the installation. Discovered the landing lights are installed 90 degrees off as well! They had the aim screws torqued all the way lens down to get them to work right! Who ever did this installation was a real moron.

 

[amillet]

It wasn’t me. I started to install my LEDs but discovered my hands were too big and clumsy to work through the opening so I let an MSC do it 

[GeeBee]

Ahh, the Bart Simpson defense. "I wasn't there, you can't prove it."

 

[PT20J]

Well, I evidently missed that note about the orientation because I checked mine today and the lines are horizontal. I just put them in the way the key was aligned for the incandescents. Maybe that's why I've been unimpressed with them? I'll fix it when I change the lenses but I'm not looking forward to messing with those little allen socket screws again. 

Skip

[GeeBee]

Apparently it is a common issue then. I closed the hangar door yesterday and turned them on. With the lines horizontal, the beam, which is an eclipse (reminds me of a cat's eye) has the two foci major axis on the vertical. Thus a good portion of the beam is on the ground right in front of and indeed below the wing and what is out there is very narrow. Obviously turning it to the lines to the vertical will cause a broad beam which is diffused by the width, making it a true taxi light. You're not helping telling me what a PIA those Allen screws represent! 

 

[GeeBee]

I started work to day to turn the lights the correct orientation. Here is what I found out.

The holding rings Mooney installed are keyed so the the notch is at the 12 o'clock. So when you slide the LED light in, it results in it being 90 degrees out of orientation. Now one could say, just turn the ring, but you can't because the hold down tabs for the rings are not. 120 degree apart. They differ. Nor is it a perfect 90 degrees off, it is more like 80 degrees.

Here is an unmodified ring on a Whelen light

Not the terminals are vertical and the key fits in at 12 o'clock, this is 90 degree out of alignment

So you have to cut a new notch into the ring, but you have to mark the 12 o'clock position first, because the factory notch is off by about 10 degrees.

Then cut the notch and re-install

 

 

 

I then re-aimed the units per the MM. What a difference!

Now you could say, how did this happen? I can only surmise that the GE 4596 installed as factory equipment is a parabolic reflector plus clear lens with no real problem in which way it is oriented,  but LEDs, both the taxi light and the landing light have distinct orientation required for the reflector and for the taxi light, the lens.

One other caution. The positive lead for the landing light can come up a little short since with correct orientation, the terminal is a little further outboard. I was able to get enough slack, but you may have to add an extension to get it right if you can't get enough slack.

[LANCECASPER]

  On 3/3/2021 at 10:45 PM, GeeBee said:

I started work to day to turn the lights the correct orientation. Here is what I found out.

The holding rings Mooney installed are keyed so the the notch is at the 12 o'clock. So when you slide the LED light in, it results in it being 90 degrees out of orientation. Now one could say, just turn the ring, but you can't because the hold down tabs for the rings are not. 120 degree apart. They differ. Nor is it a perfect 90 degrees off, it is more like 80 degrees.

Here is an unmodified ring on a Whelen light

Not the terminals are vertical and the key fits in at 12 o'clock, this is 90 degree out of alignment

So you have to cut a new notch into the ring, but you have to mark the 12 o'clock position first, because the factory notch is off by about 10 degrees.

Then cut the notch and re-install

 

 

 

I then re-aimed the units per the MM. What a difference!

Now you could say, how did this happen? I can only surmise that the GE 4596 installed as factory equipment is a parabolic reflector plus clear lens with no real problem in which way it is oriented,  but LEDs, both the taxi light and the landing light have distinct orientation required for the reflector and for the taxi light, the lens.

One other caution. The positive lead for the landing light can come up a little short since with correct orientation, the terminal is a little further outboard. I was able to get enough slack, but you may have to add an extension to get it right if you can't get enough slack.

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These was a service bulletin on the late 90's to rotate your lights and the filament would last longer, it would supposedly be less affected by vibration. The fix was to cut another notch. After that they came that way from the factory, with the notch cut in the 90 degree position. Of course, with LEDs and lenses aiming the light, that changed everything.

[GeeBee]

Yes, I thought of that. It is an old mechanics trick to orient the filament vertical as it last longer and I am sure that was the intent of the factory. 

I was looking at a Bonanza with a nose gear mounted taxi light and it had the correct keying with the key at 9 o'clock. Obviously, Mooney cares more for their customers!

 

[carusoam]

Inviting @OSUAV8TER to see the latest update...

-a-

[OSUAV8TER]

I'm glad you got this worked out and you like them a lot better now!