What I have learned about LED landing lights

[N201MKTurbo]

I do a lot of work with servo motors. The high current D-Sub connectors are pretty common. I imagine if you just wanted to have it work like a standard landing light you could splice in your existing two wires. If you wanted to use the strobe mode, you would need to run additional wires to control the mode of the light.

[PilotX]

7 minutes ago, cliffy said:

Just a question about the ":strobe" function-

If faced toward the direction of flight was its influence on "flicker vertigo" in humans assessed when reflected back into the cockpit

from clouds or haze?

https://en.wikipedia.org/wiki/Flicker_vertigo

That a “Flashdance” reference? 

[Fastglasair 1]

30 minutes ago, N201MKTurbo said:

I do a lot of work with servo motors. The high current D-Sub connectors are pretty common. I imagine if you just wanted to have it work like a standard landing light you could splice in your existing two wires. If you wanted to use the strobe mode, you would need to run additional wires to control the mode of the light.

It only needs 2 wires to do everything. That is a special large pins high current 2 pin Dsub. To switch modes, all that's required is a momentary removal of power to sequence to the next of 3 modes. No additional wires required.

[EricJ]

8 minutes ago, Fastglasair 1 said:

It only needs 2 wires to do everything. That is a special large pins high current 2 pin Dsub. To switch modes, all that's required is a momentary removal of power to sequence to the next of 3 modes. No additional wires required.

Is that function debounced inside the unit?    One of the issues with the navstrobe lights that work like that is that they often come up in the wrong state, and even worse, you may not be able to tell what state they're in.   Is there a feedback mechanism so that you know what state it is in?

 

[Fastglasair 1]

47 minutes ago, cliffy said:

Just a question about the ":strobe" function-

If faced toward the direction of flight was its influence on "flicker vertigo" in humans assessed when reflected back into the cockpit

from clouds or haze?

https://en.wikipedia.org/wiki/Flicker_vertigo

The light assembly looks very nice and IS bright 

Can you verify the approval status for installation on Part 91 airplanes and if you the requisite  PMA approvals to manufacture for certified airplanes? I don't see it on your website (I could have missed it)

As for the strobing mode, it's not much different than the wingtip strobes that do double or triple strobe pulses each cycle.

We are going to be doing STC's shortly. Experimental installations and working on potential TC'd installations for the moment. We have done FAA RTCA DO160G testing with 21/M for radiated and conducted emissions. Passing the strictest levels 

[Fastglasair 1]

16 minutes ago, EricJ said:

Is that function debounced inside the unit?    One of the issues with the navstrobe lights that work like that is that they often come up in the wrong state, and even worse, you may not be able to tell what state they're in.   Is there a feedback mechanism so that you know what state it is in?

 

Yes it's all controlled within the unit. We are offering a feedback option to confirm the mode, it uses a hall effect sensor on the power wire going to the unit located behind the panel. When first turning the light on its always on the brightest setting, as long as you wait 4 seconds or more after any momentary power activation, it always goes back to landing (bright mode) at the next momentary activation. You must not wait more than 3 seconds between button power interruptions to sequence between the 3 modes. It's actually quite simple to use. More information about the 2 color small panel located indicator LED to indicate mode is on the website.  

 

Edited July 26, 2021 by Fastglasair 1
Added a detail

[Yetti]

On 6/1/2019 at 10:42 AM, cliffy said:

Good article by one who was the GURU of light a/c maintenance from the FAA for years and years. Unfortunately he passed away a long time ago. 

Its the "Standard Parts"  that get most folks every time.  Landing light bulbs (as defined in the Parts Manual) by a number (4509) are made to an industry standard. A 4509 bulb can be made by several different manufacturers because its design is codified by an industry standard (sealed beam. wattage, type of emitter, size, shape, etc) . It is legal to install on a certified airplane just because it is made to an industry standard like an SAE AN, MS number. It needs no PMA, STC or anything else to be legal.

LED light bulbs have no such "STANDARD DESIGN" available from a recognized association such as SAE which is required to be classed as a "standard part". Therefore, "technically", it can't be installed on a certified airframe unless its part of an approved STC package. Just sayin', YMMV

Here's a question- Why do you suppose Whelan spent so much money on a STCs for their LED light systems? Could it be because that's the only way to make LED lighting legal to install on certified airplanes? 

Except SAE published LED headlamp standards in 2017.   https://www.ledsmagazine.com/manufacturing-services-testing/article/16695626/sae-adds-new-standards-for-ledbased-automotive-lighting-magazine

[jlunseth]

PTK, thank you for trying to shed some light on this subject, pun intended. Being an old guy, the amount of light that hits the runway is a concern for me. I have had two sets of LED landing lights now, and have not been really pleased with either of them. However, I have been wondering if it is the aiming of the lights that is the problem. When I taxi and the lights hit a hangar, the beams are up on the building somewhere. I realize they need to be a little high to accommodate the aircraft's descent angle, but they are not doing a heck of a lot to tell me how high above the runway I am. My night landings are meant to mimic glassy water landings, set an attitude that gives you a decent rate of descent and just hold it until the plane touches down. Very important at night to nail your speeds, don't want to be going fast at touchdown when you don't know exactly when that will be.

[Yetti]

10 minutes ago, jlunseth said:

PTK, thank you for trying to shed some light on this subject, pun intended. Being an old guy, the amount of light that hits the runway is a concern for me. I have had two sets of LED landing lights now, and have not been really pleased with either of them. However, I have been wondering if it is the aiming of the lights that is the problem. When I taxi and the lights hit a hangar, the beams are up on the building somewhere. I realize they need to be a little high to accommodate the aircraft's descent angle, but they are not doing a heck of a lot to tell me how high above the runway I am. My night landings are meant to mimic glassy water landings, set an attitude that gives you a decent rate of descent and just hold it until the plane touches down. Very important at night to nail your speeds, don't want to be going fast at touchdown when you don't know exactly when that will be.

There are adjustment screws on my F with in the cowl light.   You might try adding some washers to make it lower.   Still working to get it right.   I kind of try to make night flights with a moon.

[EricJ]

5 hours ago, Fastglasair 1 said:

When first turning the light on its always on the brightest setting, as long as you wait 4 seconds or more after any momentary power activation, it always goes back to landing (bright mode) at the next momentary activation. You must not wait more than 3 seconds between button power interruptions to sequence between the 3 modes. It's actually quite simple to use. 

Based on my experience with a few navstrobe installations which operate similarly, I find your first two sentences above contradictory with the last.   Especially when there's no feedback of what state the unit is in.   Turning final at night in turbulence is not a great time to be trying to get the landing light in the right mode.

 

[Yetti]

5 hours ago, Fastglasair 1 said:

Yes it's all controlled within the unit. We are offering a feedback option to confirm the mode, it uses a hall effect sensor on the power wire going to the unit located behind the panel. When first turning the light on its always on the brightest setting, as long as you wait 4 seconds or more after any momentary power activation, it always goes back to landing (bright mode) at the next momentary activation. You must not wait more than 3 seconds between button power interruptions to sequence between the 3 modes. It's actually quite simple to use. More information about the 2 color small panel located indicator LED to indicate mode is on the website.  

 

So the chip in the unit knows the flasher state, but you are using a clamp on watage based inside an oily vibrating engine compartment to find the status and then run through the firewall to the HMI.  Why not just have a output from the chip of status to the HMI?

If you use the connector that is on the Brittian Accutrac it has high voltage and regular signal pins.

Yep I know the relay for the LL is over on the Starboard cabin wall by the CBs but it is really hard to get to.

[Fastglasair 1]

7 hours ago, Yetti said:

So the chip in the unit knows the flasher state, but you are using a clamp on watage based inside an oily vibrating engine compartment to find the status and then run through the firewall to the HMI.  Why not just have a output from the chip of status to the HMI?

If you use the connector that is on the Brittian Accutrac it has high voltage and regular signal pins.

Yep I know the relay for the LL is over on the Starboard cabin wall by the CBs but it is really hard to get to.

No, not in the engine compartment, just downstream from the LL switch or associated relay. Behind the instrument panel. Relatively easy and clean installation. With no additional wires to the light(s) needed.

Edited July 27, 2021 by Fastglasair 1
Addl details

[apenney]

On 5/23/2019 at 9:10 PM, L. Trotter said:

What I learned about LED lights......... 

I had an interesting experience with my new Aero-Lites LED PAR 36 landing/taxi lights.They're mounted in the wing of my Acclaim. 

This past week I was traveling from Provo, Utah to Wausau, Wisconsin. I encountered icing in route and made good use of my TKS system (what a nice addition). For those not familiar with TKS, the entire wing leading edge is protected except the lenses of the landing lights. In the past, with my incandescent GE bulbs, I could turn the lights on and the heat produced would melt the ice on the lenses. The outside temperature just changed the length of time required, maybe 15-30 min if real cold (> -10C). With the LED lights on for >1hr @ -5C the 1/8" layer of ice did not even budge. Granted this is far from scientific, but a real world observation...A good thing or not, you decide. As for me, the pros of less heat out-weight the cons.

By the way, I love these lights. Even after > 1hr use, they are extremely bright and far better at illuminating the run way/taxi ways than the original GE bulbs.

I had the same experience all Winter with my LEDs.  I never had the incandescents in the wing as they were converted before my ownership.

 

[Yetti]

1 hour ago, Fastglasair 1 said:

No, not in the engine compartment, just downstream from the LL switch or associated relay. Behind the instrument panel. Relatively easy and clean installation. With no additional wires to the light(s) needed.

think it needs to go after the relay to sense properly.

Edited July 26, 2021 by Yetti

[cliffy]

11 hours ago, PilotX said:

That a “Flashdance” reference? 

No there is a debilitating medical issue called "Flicker Vertigo" first encountered by helicopter pilots when going west in a setting sun with the blades causing a flicker of the available light.

Much akin to epilepsy in its affect on humans. Real dangerous if one is susceptible. 

I would think that a pulsing light shinning fwd in a low vis condition especially at night would also cause the same affect. 

 

 

[Yetti]

6 minutes ago, cliffy said:

No there is a debilitating medical issue called "Flicker Vertigo" first encountered by helicopter pilots when going west in a setting sun with the blades causing a flicker of the available light.

Much akin to epilepsy in its affect on humans. Real dangerous if one is susceptible. 

I would think that a pulsing light shinning fwd in a low vis condition especially at night would also cause the same affect. 

 

 

I was thinking that too.   Not sure if the flat black would soak up the flashy flashy enough.   They are also finding that the way too bright LEDs on emergency vehicles are blinding drivers.  So they are having to tone it down and aim them up.

[carusoam]

I am enjoying this conversation…

It hasn’t turned commercial yet… 

 

MS has costs…. And we have commercial supporters, including a big light retailer…

Keeping the discussion technical… no real issues can arise…

 

For commercial rules and support, if interested…. Check in with @mooniac58…

Please don’t disappoint the readers or the other commercial supporters…

Keep in mind… some MSers really don’t like commercials unless they are getting real value out of them…

Kind of a public service message…

Best regards,

-a-

[cliffy]

1 hour ago, Yetti said:

I was thinking that too.   Not sure if the flat black would soak up the flashy flashy enough.   They are also finding that the way too bright LEDs on emergency vehicles are blinding drivers.  So they are having to tone it down and aim them up.

More isn't always better

[Hank]

2 hours ago, Yetti said:

I was thinking that too.   Not sure if the flat black would soak up the flashy flashy enough. 

I've not had any trouble with my LED belly blinker on the prop at night. It can be very visible on the mostly-white wings, though, as they appear and disappear in a red glow.

[Fastglasair 1]

4 hours ago, Yetti said:

think it needs to go after the relay to sense properly.

Yes that would be correct, before any relay would only sense the relay coil current. Not the higher current in high mode, the about 60% current in low mode and the pulsing current in pulse mode 

[Fastglasair 1]

7 hours ago, EricJ said:

Based on my experience with a few navstrobe installations which operate similarly, I find your first two sentences above contradictory with the last.   Especially when there's no feedback of what state the unit is in.   Turning final at night in turbulence is not a great time to be trying to get the landing light in the right mode.

 

Clarifying my prior statement. When first turning the light on its always on the brightest high setting. If you wait 4 seconds or more after any power activation it always goes back to landing (bright mode) again. You must not wait more than 3 seconds between button power initial starts or restarts to sequence between the 3 modes. It's actually quite simple to use. More than 3 seconds you keep getting the high setting. When you first turn it on if you in less than 3 seconds momentary disrupt power once it goes to strobe mode, again in less than another 3 it goes to low, the next time you interupt power momentary, you get back to high no matter how long you wait. Hopefully this clarifies your comment.

Note; starting in high or getting back to high is the easiest foolproof thing to do. It's actually quite intuitive, once it's fully explained and you "play' with it for a couple of minutes. There is also the dual colored feedback LED that can be mounted behind a translucent 3 position rocker switch. Or a very small indicator 2 color LED adjacent to the switch. We have a few solutions/suggestions for that momentary switch operation.

[EricJ]

1 minute ago, Fastglasair 1 said:

Clarifying my prior statement. When first turning the light on its always on the brightest high setting. If you wait 4 seconds or more after any power activation it always goes back to landing (bright mode) again. You must not wait more than 3 seconds between button power initial starts or restarts to sequence between the 3 modes. It's actually quite simple to use. More than 3 seconds you keep getting the high setting. When you first turn it on if you in less than 3 seconds momentary disrupt power once it goes to strobe mode, again in less than another 3 it goes to low, the next time you interupt power momentary, you get back to high no matter how long you wait. Hopefully this clarifies your comment.

This is the way navstrobes are advertised to work as well, and they often don't behave as expected.   In some installations it is difficult to get both the left and right navstrobe in the same mode at the same time, even when activated with the same switch.   Sensitivity to switch bounce is difficult to manage across switches of different makes, ages, etc., so how well the unit can tell the difference between an inadvertent switch bounce and a commanded mode change is the source of the question.   I think it is difficult to answer without testing with the specific switch to be used given the diversity of aircraft ages and conditions.   Noise or sags on the electrical system from other sources can be problematic with similar systems as well.

 

1 minute ago, Fastglasair 1 said:

Note; starting in high or getting back to high is the easiest foolproof thing to do. It's actually quite intuitive, once it's fully explained and you "play' with it for a couple of minutes. There is also the dual colored feedback LED that can be mounted behind a translucent 3 position rocker switch. Or a very small indicator 2 color LED adjacent to the switch. We have a few solutions/suggestions for that momentary switch operation.

We thought that sort of control system would be reasonably easy when we started playing with the navstrobes.   In some installations it worked well, in others it was essentially unusable.

 

 

[Fastglasair 1]

12 minutes ago, EricJ said:

This is the way navstrobes are advertised to work as well, and they often don't behave as expected.   In some installations it is difficult to get both the left and right navstrobe in the same mode at the same time, even when activated with the same switch.   Sensitivity to switch bounce is difficult to manage across switches of different makes, ages, etc., so how well the unit can tell the difference between an inadvertent switch bounce and a commanded mode change is the source of the question.   I think it is difficult to answer without testing with the specific switch to be used given the diversity of aircraft ages and conditions.   Noise or sags on the electrical system from other sources can be problematic with similar systems as well.

 

We thought that sort of control system would be reasonably easy when we started playing with the navstrobes.   In some installations it worked well, in others it was essentially unusable.

 

 

The hall effect sensing unit is voltage regulated from 10 to 32 VDC. We have very significant variations in current 60% vs 100% and then strobe mode with many 0 to 100% current variations. We can even handle the current variations of 12/14 vs  24/28 volt systems with one sensing module version. It is powered off the same circuit as the light(s). We can Alternatively provide a secondary momentary spring loaded switch with the 2 color LED integrated within, manufactured that way from a switch supplier.

Edited July 27, 2021 by Fastglasair 1

[EricJ]

15 minutes ago, Fastglasair 1 said:

The hall effect sensing unit is voltage regulated from 10 to 32 VDC. We have very significant variations in current 60% vs 100% and then strobe mode with many 0 to 100% current variations. We can even handle the current variations of 12/14 vs  24/28 volt systems with one sensing module version. It is powered off the same circuit as the light(s). We can Alternatively provide a secondary momentary spring loaded switch with the 2 color LED integrated within, manufactured that way from a switch supplier.

None of that addresses switch bounce or noise sensitivity, only feedback with an optional installation if I understand correctly.

 

[Fastglasair 1]

16 minutes ago, EricJ said:

None of that addresses switch bounce or noise sensitivity, only feedback with an optional installation if I understand correctly.

 

Well, we've used many styles of switches and haven't encountered any anomalies to date. With proper design in the voltage regulation circuitry electronic noise isn't an issue. Haven't seen switch bounce issues either.  Off to OSH in the morning, so limited response from me till next weekend.

Edited July 27, 2021 by Fastglasair 1