Guitarmaster

OK. Yep. You got me. Alright... yes, i know what an LED is and how its works. I guess I used the wrong terminology. Sorry. Im a pilot. not an engineer. So, technically NOT an open circuit, but it might as well be in terms of how the system sees it. and, yes, I did sign up for the course. It looks interesting and I always like to expand my knowledge.

OK. Got it figured out! It took some more in-depth study of the schematics, but here goes... It's not a resistive load thing like I (and Wilmar) thought it was. It's a ground lift problem. Here goes.... when the nav lights are off, the "gear down" light grounds through the nav lights. It does't matter which one. As long as one bulb is good, there will be a ground and it works just fine. When the nav lights are on, the normal ground, nav lights, is lifted and so the current must find a different path. That path is through the "dimming resistor" to a different ground. With all my grumping about crap design, it is pretty ingenious especially for the 60's. The system works flawlessly... as long as the filaments in one of the three bulbs is intact. Since LED's have no filament, there is no "hard" connection between + and - essentially lifting the ground. This could easily be solved by jumping the terminals at the bulb with a small resistor. "Also, you indicated you had a gear issue that it wouldn't retract all the way. Did you get the "gear unsafe" warning and no movement of the gear (as indicated by the floor indicator) or did it partially retract and then stopped?" Yes, I thought the two might be related, but I think it is just coincidence. I came up partially and stopped. It was cold out so in retrospect, the squat switch may be the culprit here. I am thinking a bypass switch will be installed at annual. Probably new biscuits are in order as well. Gear shift.... The guy at Wilmar said the down limit switches in these airplanes are a problem and they replace MANY in airplanes displaying the same symptoms as mine. I am sure that is the problem with no gear in the freezing temps. The plane has been more of a project than I wanted, but it has been fun!

It's a good question. I would bet there is some resistance built into the unit.

I thought of adding a resistor, but of course, the airplane is certified so.... If you ohm out the nav system, it is roughly 5.6 ohms per bulb. Only one in the circuit seems to solve the problem so it doesn't take much.

Here's the scoop straight from Willmar. The Pre-J Mooney's with the electric gear have to have a resistive load installed in the nav light circuit. It is part of the dimmer logic Mooney used in the day. The gear indication will not work otherwise. Understand, this is with the nav lights off. IN ADDITION, because of the way the circuit works, it can affect the operation of the gear itself! This explains the flight home the other night in which the gear would not retract all the way. That was a slow flight at 115 MPH. IMPORTANT!! If the nav lights are not working (no resistance in the circuit), there is a good chance you will have gear problems. I love my airplane, but what a crap design. I called Bob at PSA and told him about it. He said they would see if there was a way to design the bulb to work with those systems. The bulbs are great!!! I just can't use them. On a side note, for those without electric gear, I happen to have two paddle bulbs with the clear lenses for sale.

The title say it all. Strange but true. As a follow-up to the installation of the PSA Paddle bulbs, I have this to report... For reasons unbeknownst to me, the nav light circuit must have a resistive load in order for the "GEAR DN" light to work. Here where it gets even weirder; this occurs while the nav lights are OFF! I re-installed the incandescent lights and voila! "GEAR DN" illuminates. I decided to do some experimentation. With one incandescent nav installed, everything worked normal. Both installed, of course it worked. With both removed, no "GEAR DN" light. My conclusion is this. Mooney runs the nav light circuit through the gear circuit somehow. Probably for the dimming feature. For the indication system (it doesn't affect the "GEAR UNSAFE" at all) to work at all, it relies on a resistive load through the nav lights. Maybe Clarence can shed some light?? So, after all that, and the long "discussion' from the other thread, I'm back to the incandescents. Now to see if Spruce will take them back... after that, a call to PSA to let them know of this issue.

If you turn off the lights then the load is zero, and the Gear down should be bright. Agreed. I don't believe in coincidences, but in this case, I think I may have something else going on that just happened coincide. There are issues going on with the gear not wanting to come down in cold weather so it may be related to that. Sent from my XT1254 using Tapatalk

Freezing rain at its best.. Or worst. . Good job on not pushing it! Sent from my XT1254 using Tapatalk

What he said ^^^ Welcome! Sent from my XT1254 using Tapatalk

Right, but this is with them off. Sent from my XT1254 using Tapatalk

An unexpected result of the LED's... the "GEAR DN" became dim. Weird. I don't see how changing from a resistive load of the incandescents should have any bearing on the down indication. Time for a review of the schematics. Things that make you go... hmmmm.

Bling is good...

Maybe, but at what cost? Making an incandescent brighter takes a lot of current and produces much heat. Is it possible it just wasn't worth the trade-off? I have yet to see a manufacturer go significantly beyond what is required by the FAA with regard to required equipment... unless it's cost effective for them. During my first visit to KOSH, LED technology was just getting started. The display (i can't remember the manufacturer) had a Kitfox outfitted with LED nav, strobes (3), and two landing lights. All were illuminated with an ammeter attached. The total current draw was ~6A. This made it very feasible to outfit an experimental, with a tiny alternator, with a full compliment of exterior lighting. I don't know about all GA airplanes, but all new airliners are coming from the factory with all LED lighting. IMHO, unless you are going for a show winner restoration to original, why not install modern technology in our vintage birds? Isn't that what we do with avionics upgrades? The old gyros work perfectly fine, but you won't find one in any modern airliner.

I flew freight years ago in Turbo Seneca2 and Chieftain mainly from KBFI to KGEG. In those years, I dealt with ALOT of ice and I am intimately familiar with PNW flying. My first reaction is don't do it. The airplanes I were flying were FIKI. Boots, heated windshield and props. The PNW, specifically the western slopes of the Cascades are huge known ice makers. So much so, there is a FAA advisory circular on it. Twice I was not able to out-climb the ice accumulation WITH the boots doing their job simply because of ice weight. Once I descended, not by choice, over the mountains with full power and 500FPM down. the controller vectored me through Stevens Pass until I got low enough for the ice to come off. The latter party started off at 10000ft and ended at 3800ft where the warmer air was. There was roughly 8 inches of ice on the unprotected sections of the wing. That amount accumulated in about 15 minutes. I have a picture of it somewhere. Anyway, if you HAVE to get across the mountains, do the shuttle climb. That is to fly west, climb and cross at 9000+ feet. This keeps you out of the worst of it USUALLY. Again, in a non-fiki airplane, I wouldn't even bother... unless it was really cold. Like -25c cold. At that temp the water droplets make their own condensation nuclei and you have ice crystals which will not produce airframe icing... probably. Escape route is PARAMOUNT. If you shuttle climb, get into ice over the mountains, you can turn around and descend. On a side note, watch out for MT. Rainier + high winds. I bent the main wing spar on a Seneca2 on V2 over the mountains one night in mountain turbulence. 130kt winds over the rocks. I was a very lucky man that night and nearly gave up flying all together!

For me, its two-pronged. Better brilliance from the light. IMO, the LED lights get your attention far better than an incandescent. The big one is current draw. It may be overkill, but with a 40-year-old airplane (and wiring to go with it) pulling 6A for three bulbs with all the heat associated with that, is worth it to me. For sure the Grimes is less expensive, but as someone who loves electronics and designing circuits, I see benefits to the more expensive bulb. Of course, it may all be just be in my head. Trust me, you DON'T want to go there!

This is what came with the bulb. They are not TSO, but they do satisfy the requirements. Is the Grimes light TSO? Just wondering. I pulled an automotive bulb out of the tail.

This was a concern of mine as well. The early ones suffered from this problem. These actually have CREE LEDs along the edge. They are very bright all through the field of view.

It is true that digital cameras are sensitive to LED. I can say this though, it is very hard to look straight at them. Comparing the grimes to these, they are more brilliant. Also, the digital camera does not capture the depth of color. No, they do not strobe. Anything that functions differently would not be a direct replacement.

I installed the PSA paddle bulbs and the results are great! They are considerably brighter than the incandescents and with better color depth. The best part, 6A of power gone, replaced by .75A. 88% decrease. Thats huge! Especially with 40-year-old wiring. Here are a few pics.

just had lunch at Dukes in Waikiki....did not think about my Mooney once.......did think about all the Bikinis I saw........ Instead of a C model Mooney how about a C model Bikini: I know what you mean Jim. Nothing like a hottie in a bikini. Sent from my iPad using Tapatalk How did I know this was coming Chris.... Sent from my XT1254 using Tapatalk

Yep. Sounds like you have been infected! You should know, there is no known cure. You can occasionally ease the symptoms by judicious application of 100LL. A word of warning... don't give her a name or all your money will disappear! I, myself, was warned too late. Congrats on the new mistress!

<Jealous>... You have cam locks on your avionics baY? Nice. Mine are 10/32 screws. SS at that so the heads strip easily.

It was very old. It was in the plane when I bought it. Overhaul date was 1987 and it was a serial number 38xx. Mod 1 on the gyro was done. Mod 3 on the square part. According to PSI, as long as the "coffee can" has mod 1 done, it can be overhauled regardless of age. If there is no sticker on the top, remove the coffee can via the three screws on the shock mount and look on the underside. It failed by refusing to move the compass card on the HSI. Oddly enough, The HDG flag never showed itself. It just stopped turning. The KG102A was making noise prior to this happening so I know it's lifespan was short. It is weird that it didn't show the flag so I think mine had other problems in addition to the gyro.

I don't use SV. Although I think I will add SV when I renew this year.

Thought I would follow up. I did an OH exchange on the KG102A with PSI Instruments. Interestingly, the new gyro would not pull the HDG flag but would rotate the card. After a few calls to Rick at PSI to do some troubleshooting, I finally got it nailed down to running on battery voltage. When I plugged in a charger and the voltage increased above 12v, the flag went bye, bye! Now, all works well. Big time happy dance! Kudos to Rick and the gang over at PSI! $1,500, a three-day turn around and troubleshooting help on top of it! Now on to the all the upgrades I got for Christmas