Led lighting (merged)

GE 4700 LED replacement

I have a GE 4700 combined landing and taxi light bulb in a PA28.

What options do I have to replace it with a LED light? As far as I know, there are no direct LED replacements for the GE 4700 bulb.

The maintenance manual, parts catalog and pictures on the web lead me to believe that this isn’t original, and that the plane must have been shipped without taxi light, just the landing light using a standard 4509 bulb, for which plenty of LED replacements exist. So is my only (best?) option to go LED to convert the plane back to TC standard and then replace the 4509 with a LED landing light?

If indeed not LED is available for that one, it is likely the most economical methode. Return to TC standard wouldn’t require a modification, and upgrading at that point with LED would could done using CS-STAN procedure.

In my opinion the distinction between taxi and landing light is obsolete. The modern LEDs do both very well with the same bulb. Having two lights means more light than one.

achimha wrote:

In my opinion the distinction between taxi and landing light is obsolete.

The distinction between those is the beam width, 10°/40° horizontal for landing/taxi light and 10° vertical for both. The GE4700 bulb has 100W in both modes, so an object illuminated in taxi mode should be 4 times less bright (2 aperture stops) than illuminated in landing light mode. I guess the optimal replacement would be a LED bulb with 4 times the light output of the GE4700 and taxi spreader, that way you get taxi light field of view with the brightness of landing mode, but that is probably not covered by CS-STAN.

achimha wrote:

Having two lights means more light than one.

That’s one aperture stop difference. I guess this is hardly noticeable given the logarithmic nature of the eye.

Is there an LED equivalent for the old Wheelen wingtip light cluster?

(I think the above photo has the wrong colours on the end lights)

Is there such a thing?

I know various solutions exist for homebuilts but I don’t recall seeing a TSOd or PMAd replacement.

Especially the strobe section would be nice to replace because the strobe inverter is a nasty interference-radiating box which costs a load of money.

I think it’s the Whelen Orion 600:

http://m.aircraftspruce.com/pages/el/ledlighting_vwing/whelenorion.php

That’s great – thanks Roger.

Someone reported installing it on a Mooney so it looks like it is a certified replacement.

They aren’t cheap – the price is for one so this is over $1000 for two. Plus one “needs” to run a sync wire from one wingtip to the other.

1000 bucks is the going price for two led lights believe it or not…

http://m.aircraftspruce.com/catalog/elpages/ultragalactica.php?recfer=3036

The homebuilt version, I believe, came up here

Posts moved from another thread

There are previous threads on LED lights e.g. this one which at the end has a link to a longer TB20 one.

There are several issues I see with these which limit adoption and therefore stop people flying with them on all the time (at low level, anyway):

• Higher cost – about 10x to 20x more than the normal lamps

• A huge amount of concern / FUD about their legality, assisted by disinformation and supported by some EASA21 firms having obtained STCs for specific types which give the impression that an installation not supported by an STC is illegal

• They may not be precisely dimensionally identical so e.g. the TB20 installation (see above link) needs a slight modification to the spring clip (takes about 10 mins)

• They draw much less current (e.g. 1.5A, versus 4A for the old ones) and in say the TB20 this prevents the cockpit “lights on” indicators working; this has given rise to yet more FUD and worry about legality especially on the Socata owners’ group where they run a pretty strict line on anything “unapproved”. There is a simple enough mod but most maintenance companies will not touch it with a bargepole so the only way is off the books.

I wonder why some pitot tubes burn out? On the planes I trained on, every single one had a dud pitot heat. Every one. But mine is now 14+ years old and is fine, yet it is the standard widely used US-made one.