Lycoming Serial Number AD and TruTrak Questions

So two questions for the experts out there. I'm looking at buying a core and overhauling it with some local help as an option for my powerplant. I have some great advice on what to look for in a core, but am running into issues deciphering Lycoming's SB using the serial numbers. Does each engine have a unique serial number like VIN's or are they assigned to a production run type thing? For example, an O-540-A1C5 is listed on the AD/SB, but only one serial number with no range (for example L-XXXX-XX, not L-XXXX-XX thru L-XXXX-XX).

Second, I'm trying to figure out the difference between the trim-sensing autopilot servos and regular DSP-C servos. Can I add the auto trim module to either one or is there any other huge advantage to having the trim-sensing servos other than auto trim? I'll be using the AFS5000 series on the panel and would like to control AP thru the EFIS but will accept having the AFS Vision head if I have to.

Thanks in advance for all the help!

The engines do have a serial number and if your serial number is on the applicability listing then that AD would apply..

Tim,

I would recommend giving Rob or Ken at AFS a call to explain the various options you may have with their EFIS. Since the AFS purchase by Dynon, you can sometimes mix products fromm both companies. I can't speak to the level or if the Dynon AP products are integrated with the AFS EFIS.

I can only speak to the Trutrak option. Like you mentioned, you'll need an AP head. The newer Vision based unit or the original AFS-Pilot. Then you'll need the roll and pitch servos. I highly recommend getting the automatic trim module. Most folks think that the yaw damper module is overkill in a RV-10.

Personally, I prefer the external AP head. While it's an extremely small risk, should the EFIS fail, the standalone AP can buy you think time if you are in IMC.

Bob

TruTrak Question

I agree with Bob. A separate autopilot head gives you added redundancy and a big help if the EFIS dies. This is an IFR issue and not a big deal if you are VFR only.

Skip the yaw damper, but if auto trim is an option then I recommend it. I presently do not have it but plan to backfit it soon.

Bob, good advice and that's what I'm hearing from other folks. I plan on having a very capable IFR aircraft so extra redundancy isn't a bad thing for me. I called Stein and talked to Jed, but he was a little out of pocket so I need to get a hold of AFS directly for the AP questions.

For the engine, I did discover the answer to my question. They are unique serial numbers. I guess there was literally just one A1C5 that was affected by said SB.

You learn something new everyday!

I just deleted some messages in my PMbox a few weeks ago that had all the info on whether a trutrak servo is trim sensing or not... I'm not positive, but it seems like the trim sensing servos have the letters "TS" in the part number.

AFS is now supporting the Dynon auto pilot servos (in Alpha testing, but full release fairly soon). If you have 2 screens, then the auto pilot will function from either screen since they are tied into the Skyview bus. If either screen fails, you still have auto pilot from the other screen. This is the least expensive option. Also, if you get the auto pilot control panel, then you will have auto trim as well.

For the TruTrak servos, you need the trim sensing servo to be able to add the auto trim module.

Give me a call if you would like to talk through the benefits and drawbacks of each option.

For the TruTrak installations (at least in an RV-10), it's only the pitch servo that is trim sensing.

Bob

Sorry I missed this! The DSP C TOR is the part number that you use for pitch. The RV10 servos are pretty different since the pitch servo has the torque enhancer on it and the roll servo does not.

If you want to add autotrim to both axes, we can do that. It just requires a trim sensing servo to roll as well and an additional autotrim module.

If you already have the servos, just give me a call and we can hash out a deal on the Vizion head. Let me know how I can help!

Lucas, thanks for the info. I feel much better about my purchase now!

For those following, I purchased the DSP C TOR (pitch, trim sensing servo for the RV-10) and the DSB C servo (roll, non trim sensing). The DSP C can be added to the Vision Pilot head and auto trim module with no modifications. The DSB C will need to have a little reworking done by TruTrak, but can be made to trim sense. I will need to use the Vision Pilot head (round or flat pack) which of course can be integrated with the EFIS.