gahorn wrote:...I have standard 4509 landing lamps and 4461 taxi lamps in my custom dual light installations written about elsewhere.
I have on order an LED which claims to be a "perfect" replacement for the 4509, which I will trial and write about here and perhaps the 170 news. It is U.S. made by Grote and costs about $100 at amazon. I plan to install it in one of my dual landing lamp mounts, and thereby have a fair comparison of the performance versus the original incandescent 4509. I am not doing this because I want/need LED land/taxi lamps. I consider $100 each to be outrageous. I am only doing this out of LOVE for you guys. 
It arrives in a few days and I'll try to get a report written by the end of the month.
For the impatient, here is the product, and it sells for $99.99 at Amazon plus $10 shipping.
Grote Trilliant® 36 LED Whitelight Work Lamp 63821-5
I received the product and installed it in my right wing position. (Many of you will recall I have a mirror-image, dual landing/taxi light installation.)
The Grote light is indeed a very good quality lamp. It is strongly built, and an exact fit to replace our PAR 36 4509 landing lamps. It was an easy install, exactly replacing the PAR 36 lamp.
Remember that I have one 4509 and one 4461 PAR 36 lamp in each of my dual installations. The 4509 is a 100 watt landing lamp which has a clear, spot-light beam type lens,... and the 4461 is a 60 watt taxi lamp which uses a "Fresnel" type (more of a "fog" or "scattered" beam lens. When I decided to install dual land/taxi lights I purposely selected the 4461 for my taxi lamps because I wanted more of a "wide" beam illumination when taxying,... while I enjoy the longer-projection "spot" pattern of the 4509 for landing lamp purposes.
For this test, I installed the Grote LED lamp in my right "taxi" position. This removes the right 4461 lamp in my right wing and allows a direct comparison to the 4461 in my left wing. Here's what I found:
The Grote lamp is an EXCELLENT replacement for the 4461 taxi lamp. It makes a MUCH better TAXI lamp than the 4461.
It also makes a MUCH BETTER TAXI lamp than the original 4509 taxi lamp which Cessna installed.
It makes a much BRIGHTER light and also makes a MUCH WIDER illuminated area than my 4461 taxi lamps. However, in comparison to the original 4509 landing lamp, it does not provide the depth/distance of illumination as does the original 4509 landing lamps. This is what I actually expected as that is the reports that I have had from other LED substitutions when compared to incandescent lamps.
The original incandescent PAR 36 lamps are more "yellow" while the Grote LED is more "sunlight" brilliant. I definitely PREFER the Grote LED
color for illumination. I also PREFER the Grote LED as a TAXI lamp ...than either the 4461 incandescent... OR EVEN the original 4509 Landing lamps being used for taxi purposes. (With my dual set-up however I do not intend to leave the Grote unit installed. If one has only a single land/taxi installation I believe the Grote LED is a superior lamp for the taxi lamp position.)
If I had only the original set of landing/taxi lamps which Cessna installed in our metal-wings.... here's what I would recommend:
Keep the original 4509 PAR 36 lamp for a LANDING LIGHT.... but remove the 4509 TAXI lamp, and REPLACE IT with the Grote LED product for a TAXI lamp. I think everyone would be extremely pleased with the increased illumination of the Grote LED in the TAXI position because of it's brighter color and greater spread of illumination for taxy purposes, and would also enjoy a HUGE reduction in electrical demand while using the taxi position as an anti-collision light in congested areas (yet still retain the distance-capability of the 4509 landing lamp when entering the pattern and lining-up on final for landing.) The Grote LED is advertised with a 40,000-hour life. This should mean that as an anticolllision/recogniton and TAXI lamp it will likely be the LAST TAXI LIGHT you will ever purchase.
But I do not think it will satisfy you for a landing lamp. For that you will be happier with leaving one of the 4509 lamps in place for that purpose.
To reiterate, .... in my opinion, the Grote LED is the perfect TAXI lamp replacement and I would recommend removing the 4509 taxi lamp and installing the Grote LED in that position.... while keeping the 4509 in the LANDing position. I think that would be the PERFECT SETUP for anyone who has the original land/taxi lights in their 170 A/B or 172, and might give some relief to those who have experienced short life of their 4509 lamps (because the Grote LED would take on the task of anticollision/recognition service) while IMPROVING the TAXI-light illumination of the original setup and simultaneously reduce total electrical demand.
I do not recommend the Grote for a replacement of the LANDing light or to replace
both lamps, however.
Now that I've run this test, I have a deal for anyone who might want a Grote LED PAR 36 with only ten minutes of use on it... (I will be keeping my dual-setup intact)... I will ship it to you and I will pay the freight. (You only need pay for the lamp - $99.)
By the way, I checked with one of our Members who runs a trucking repair/service facility and found that this price is about $30 below wholesale... so if you want one,
this is your opportunity to get it below wholesale and free freight.)