Landing light-4509 or 4509Q?

[smcnutt]

My landing light burned out and the one in the plane has no P/N on it. I looked up the P/N as a 4509 from the Piper CD and ordered it from Aircraft Spruce for less than $10.

However, as I'm replacing the light I notice that the inside of the old light is not the same as the new light. The old bulb seems to have a second glass bulb as well as the typical element inside. I presume that the burned out bulb that I pulled out was a 4509Q. I read some stuff about using the Q bulb before I ordered but decided I would just leave it original and use the plain 4509. Some of the discussions said the Q bulb pulled more power and your wiring may not handle it, etc. and I didn't want to melt anything. However, now that I find that the plane already had the Q bulb and I see that it really is MUCH brighter (the taxi light is still a Q bulb) I am wondering what the general thoughts are on using the 4509 or 4509Q bulbs.

[Steve Pierce]

I did some research on this years ago but my memory doesn't serve me well. I seem to remember the Q lasting longer.

[smcnutt]

Yes, from what I read the Q is rated to last 100 hours vs. 25 hours for the regular. However, some said the Q which stands for quartz, draws more amps and/or quartz bulb burns hotter. If true, either of those would be a bad thing. Both are listed as a 13v-100w bulb so I don't know if that dispels the amps draw argument or not. Have no idea about a quartz bulb burning hotter.

[JohnW]

Yes, well...few things in this life are actually Cast In Stone. One is, however...that is Ohm's Law. Volts X Amps=Watts. The voltage (for purposes of THIS "argument") stays the same. If the "watts generated rating from the lab" for each bulb is the same, them by golly gosh, the amperage must be, too.

I cannot speak to the ACTUAL operating temperature. I DO know my Daily Driver has had Q bulbs in it since they came out. While I am NOT a "night-flyin' regular" guy either THEN or NOW, I replaced my "standard" 4509s when they failed to answer the call at Annual, which had been "averaging" around 3-5 years. So, HOW LONG have the Q's been available? I dunno (that's what Oldzheimer's does for ya!) but it has been awhile now, and they are still the same Q bulbs. I don't "never turn them on"...I use them (as much as I get into "airspace") for conspicuity a reasonable amount.

I can't believe that there is anything even remotely APPROACHING what you could call a "fire hazard" from them, one way or another. I can see someone with a very limited Secondary Education connecting the dots something to the tune of: "Ehhh, I can SEE that one is brighter than the other. That must mean it gets HOTTER than the other, that's the only way you can get more light! Fo' Shizzle" Well, I never melted a single LL lens, my wiring has never caught fire (or even "smelled a little"), and I have never heard about a Maintenance/Defect report for heat issues due to replacing regular incandescent LL bulbs with 4509Q bulbs.

And lastly, I rarely (although sometimes I DO) value info that comes from "Hanger Flyin' Sessions". (First off...a "hanger" is what you hang your raincoat on, altho' it IS possible that your keep raincoat hanger hanging in your "hangar". I can't for the life of me envision people "hanging" there airplane inside their "hangar". "Hangering" means "applying a hanger so's you can hang it up", donut?). If there IS some scientific basis to the claim that quartz LL bulbs "run hotter", then even if it IS so, how come I have NEVER heard of anybody having an "incident" because they had Q bulbs installed in their Piper LL?

[smcnutt]

Well, that's the kind of info I was looking for. However, you kind of lost me at the part about hangars, hanging and such ;)

At this point, since I already bought them I will probably use the 4509 for the taxi light and put the good 4509Q into the landing light place. That way I have the brighter landing light and can use up the std. light that I have. Besides, it would cost me as much in shipping to return the 4509 anyway.

[smcnutt]

You know nothing is EVER simple. I went to replace the burned out bulb and now I'm not sure if it's acting properly now that I've replaced it. However, I really wonder how I could have screwed up replacing a lightbulb. :oops:

Not sure if this is a wiring issue that would be specific to my plane and therefore not be something that could be answered here. In my airplane I have a single 3-position toggle switch for the taxi/landing light. In the center position everything is off. Flip it to the left and it's marked landing light and to the right it's the taxi light. Besides changing the bulb, I've not made any wiring changes.

Now that I've replaced the burned out bulb when I flip the switch to the left (landing light position) just one light comes on -the outer light. However, when I flip the switch to the right (taxi light position) then BOTH lights come on. I don't remember it being this way before I made the bulb switch but I guess it's entirely possible that I just never noticed. I mean I've not done a lot of night flying and therefore not paid much attention to exactly what turns on when I hit the switch.

I've looked at the wiring on the Piper CD and it looks pretty simple. A common ground between the two bulbs and a separate power wire for each. Each light position simply has two wires coming thru the individual mounts and I know I didn't change that. That means each bulb has only two wires (left & right, power & ground) that could be attached to them. Is there any way I could have made this change in light function by simply attaching the left/right to the wrong side of the bulb? Can't imagine this would be the case but I thought I would ask.

Next question, should both lights be on at the same time? If so, I would assume that should be the landing light position (both lights on) on the switch and maybe I have the switch marking backwards. The plane was recently rebuilt shortly before we bought it so this may be something that that way from the start and nobody noticed.

Feeling kinda stupid here but see my signature line below. :roll:

[mjlossner]

WOW! I'm waiting to hear what everybody has to say about this one. My lights work the same way and I just figgered somebody hooked up the wires wrong at the wing root when they put the wings back on several years ago. I've just been to lazy to find and fix it (its to easy to just flip the switch the other way). have more fun flyin it than fixxin it!!
Mike

[smcnutt]

WOW! I'm waiting to hear what everybody has to say about this one. My lights work the same way and I just figgered somebody hooked up the wires wrong at the wing root when they put the wings back on several years ago. I've just been to lazy to find and fix it (its to easy to just flip the switch the other way). have more fun flyin it than fixxin it!!
Mike

One position is a single light and the other position is both lights?

[Rick-CAS]

Should have both lights on when landing lights are selected and one light for taxi. The jumper wire is on the back of the switch and is normaly forgoten (one light on in either position) or the switch installed upside down so it works backwards. Turn switch to taxi marking on panel and get landing lights (both) at wing. Easy to fix right in the cockpit.

[Gilbert Pierce]

Mine worked that way also. Mine was wired with a DPDT switch and wired such that one light came on when in one position and both lights came on when the other postion was selected. This is in accordance with drawing 14442. While it is not real clear the the JUMPER noted on the switch is what causes both lights to come on in one postion of the switch.
I have since changed the landing and taxi light to individual switches so that I can control one or the other or both.