Message-ID: <19980924000758.11536.qmail@www05.netaddress.usa.net>
Date: Thu, 24 Sep 1998 00:07:58
From: Dan Schaefer <dfschaefer@usa.net>
To: lancair.list@olsusa.com
Subject: misc.
Mime-Version: 1.0

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Several of us flying the 235 airframe with the earlier flap mechanism here in SoCal, have experienced the actuator jamming in reflex position. Can't say for the other guys, but mine (three events in 455 hours) was caused each time by the magnetic limit switch mot limiting a thing - it looked like the magnetic portion of the rod just slipped right on by the switch. As I said in an earlier post, am planning to replace those with direct-acting switches at my next annual (the mechanism is gonna have to drive, physically, right through the switch if it fails to limit).

I couldn't agree with Guy Buchanan more regarding important things like hinge attachment methods, among others. It seems to me that when one contemplates a modification to proven assembly techniques in such safety critical areas as the flight controls, that person had better better get way knowlegeable about the structural parameters your dorking with - and then learn about, and how to accomplish, a Failure Modes & Effects Analysis (FMEA). If it's a weight thing bothering you, when you look at the metal fasteners, lose a couple of pounds - both of these things will help keep you healthy.

To BIll Rumford about wiring your icom direct to the battery. Worth a try but recognize that the icom will be interfaced, via the shields on the signal cables, to the ground of your other audio sources. So that messes up getting a pristine path for it's ground back to the battery. I wouldn't rule anything out when it comes to dealing with noise. N235SP had been relatively quiet for the first 100 hours, and then one day, while making my first call to Ground, I had an awful sound in the head phones and ground could hear it too. I thought something had failed it was so bad. Long story short, for some reason I had left the copilot headset in the hangar for the first time, and when it was plugged back in ZOWIE!! all was fine once again. Apparently, just having the audio cables up to the plugs, un-terminated (by the headset) was enough to cause the problem - makes sense, I guess they must've made great antennas. Tells me that noise, in this case probably RFI, was getting into the system via those cables. Also tells me that you never know where your problems might come from when it comes to noise. That is, unless you plan to spend a couple hundred thousand bucks (that's, like, a whole LOT of beers!) at Dayton T. Brown, or somesuch, laboratories for RFI surveys.

To John Cooper, I should have said, I can only speak from knowlege regarding the batteries brands with which I have experience. My dealings with both the Concorde and Hawker (from the UK) folks makes me a believer in setting the charging voltage for their RG SLABs to 13.8. Since I haven't used BC's product, I can't comment. However, if you don't get the life you think you should from you RG battery, you might consider that the guys who MANUFACTURE the things may have a better handle on their requirements for care and feeding. Also, I agree with you that Bob Nuckolls (Aeroelectric Connection) makes some great stuff - I installed one of his adjustable linear regulators, and added his over-voltage protection module too - should be in all our planes.

To Jim Franz, GEEZ!!! If you don't do SOME zipping, popping, clicking or humming now and then, most tower crews probably won't believe they're talking to an airplane, there may be such a thing as too much of a good thing! So be careful, they may think you're just trying to mess with them and call the Federales.

Cheers,

Dan Schaefer


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