Belt Tension Reference
In the June issue of KITPLANES® on page 34, the reference for checking alternator belt tension with a torque wrench is given as Lycoming Service Instruction 1129A. This document isn’t available at www.lycoming.textron.com. Has it been cancelled or superseded?
Dave Prizio responds: There is now a Service Instruction 1129B, which is an updated version of 1129A. Unfortunately, it is not listed on the Lycoming web site. However, it is in the more comprehensive book of Lycoming publications available to mechanics by subscription from Lycoming.
On page 24 of the July issue, the photo caption says “the author mounted the camera under the left wing of his RV-8.” It is clearly under the right wing as viewed from the pilot’s seat. Just thought I’d let you know I read the article!
The editor frequently flies aerobatics and often isn’t sure which is the left, and which is the right wing. That’s our story, and we’re sticking to it! (And we’ll do a better job of catching such errors in the future.)
In the June issue, Gary Jones talked about needing a more powerful Dynon servo for his Glasair 2FT. What size did he end up using?
Gary Jones responds: I used the middle servo. I think it was the SV42.
To Teflon or Not…
Teflon tape works great, but it works even better if you put the tape on the right way, instead of winding it as shown on page 42 of the August issue. In delicate hydraulic systems, maintenance personnel do not like using Teflon tape; it generates shredding contamination and can easily clog small valve orifices. What they prefer are Teflon pipe thread sealers like Permatex or Teflon pipe dope, the same stuff plumbers and gas fitters are using. Loctite Red is also mentioned, but I hate having to use heat to remove a fitting; the heat threatens to damage the oil cooler’s brazed joints.
Tony was among several readers (and some of our staff) who questioned the use of Teflon tape on oil lines. It is generally discouraged—not because it doesn’t work, but because you have to do it exactly right. If you carelessly overlap the end of the fitting, you can FOD the system. Therefore, it is easier to teach people to use something else than risk that they do it wrong. Factory (or maintenance facility) personnel can be checked by quality systems to make sure that there are no issues—field installations cannot assure this level of control.
As to why it was wound backwards, we are as baffled as our readers. I think we have to chalk it up to a staging error while setting up the photo.—Ed.
Sharp-eyed reader Sean Byrne noticed an incorrect picture in the Onex article (June 2013). The cockpit/panel picture is not the Onex; it is the single seat Sport Acro version of the original Sonex. We apologize for the error.
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