---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 09/09/04: 9 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:15 AM - Re: P-static blew my VM1000, autopilot and trim indicator (J. Oberst) 2. 07:23 AM - Transmitter/Autopilot interference (J. Oberst) 3. 07:51 AM - Re: Transmitter/Autopilot interference (Bruce Gray) 4. 08:26 AM - Re: Transmitter/Autopilot interference (Paul Schattauer) 5. 08:43 AM - Re: Transmitter/Autopilot interference (Bruce Gray) 6. 08:47 AM - Re: Turboprop and rocket engine (Robert L. Nuckolls, III) 7. 10:52 AM - Re: Re: Contactor Torque (Bobby Hester) 8. 12:45 PM - Re: Got Lockwasher? (DAVID REEL) 9. 02:48 PM - Making neat cable runs (DAVID REEL) ________________________________ Message 1 _____________________________________ Time: 07:15:22 AM PST US From: "J. Oberst" Subject: Re: AeroElectric-List: P-static blew my VM1000, autopilot and trim indicator --> AeroElectric-List message posted by: "J. Oberst" I've flown my Glasair Super II in a lot of IMC, but never the dry, snowy kind (thanks to living in Arkansas). A friend who has the same type airplane and lives in the north has had similar static problems flying in snow (he is not IFR-rated) but has not had anything fail. I think I'll avoid dry snowy conditions whenever I can! Jim Oberst ----- Original Message ----- From: "Dan & Kari Olsen" Subject: AeroElectric-List: P-static blew my VM1000, autopilot and trim indicator > --> AeroElectric-List message posted by: "Dan & Kari Olsen" > > Greetings, > > I am new to this group and was referred here by some fellow Lancair > builders from the Lancair Mailing List. > > Last Friday I was happily flying my Lancair 320 from Colorado to the > Lancair factory fly-in when I entered actual IMC. I encountered a few > light snow showers in the clouds when the P-static started in. The > usual cracking and buzzing in the headsets, hair standing on end, etc. > The encounters lasted only 30-60 seconds or so. On the first encounter > my TruTrak DigiFlight II autopilot disengaged. When I looked at it the > display was blank but the circuit breaker had not blown. I cycled power > to the autopilot and only the LCD backlight would come on. At this time > I discovered that the VM1000 engine instrumentation system had frozen. > The display was showing all the parameters as they had been but nothing > would move or react to changes. Cycled power to this and it worked > again. > > A couple minutes later another P-static encounter. This time the VM1000 > started displaying garbage and then blank. Power cycle to the VM1000 > did nothing - it was dead. The Jim Frantz AOA also started going nuts > and then just quit. I also discovered that the Ray Allen pitch trim > indicator (LED type) quit, although the trim servo still worked. > > All through this the UPS Apollo transponder, GPS/COM and NAV/COM kept > working flawlessly. I quickly contacted center for a 180 out of the IMC > and amended flight plan to get me back in the clear and on the ground. > A few minutes after back in the clear and the AOA began working again > but everything else that had died remained dead. > > So, now I have a couple problems: > 1) get the broken equipment fixed; and > 2) figure out how to prevent this from happening again > > I talked with Jim Younkin at TruTrak and he has a good idea of what the > problem is with the autopilot (discrete part that they have recently > discovered is not meeting spec in terms of rapid rising voltage > transients). It's already on its way to Jim. The folks at VisionMicro > don't work on Fridays, so I have no answer there yet. > > What concerns me the most is the prevention part of this. Because my > plane is made of e-glass, static wicks are not an option. Can any of > you give me pointers on what I might do to protect the sensitive > electronic gear in the future, besides avoid flying through snow? > Better grounding? Chokes inline with some of the lines? Zener diodes? > > It is interesting to me that some of the equipment worked like a charm > through this all. The avionics stack and LCD clock/OAT/volts. > Basically, all of the "certified" gear worked flawlessly and the > "experimental" equipment crapped out. > > I am also very interested in the experience others have had in IMC. I > have only had my 320 in IMC twice. Once in warm, wet clouds and rain > with no problems or static at all. This time in cold, snowy clouds. > Unless I can put my finger on something that can protect the gear, I > will have almost no confidence to take it in any IMC - warm or cold. > > I look forward to your replies. > > Best Regards, > > Dan Olsen > Lancair 320, N320DK > Fort Collins, CO > > ________________________________ Message 2 _____________________________________ Time: 07:23:56 AM PST US From: "J. Oberst" Subject: AeroElectric-List: Transmitter/Autopilot interference --> AeroElectric-List message posted by: "J. Oberst" I have an S-TEC system 55 A/P in my Glasair Super II. When the A/P is in the vertical speed or altitude-hold mode, and I transmit on my Garmin GNS 530, the autopilot is affected and my airplane pitches down. If I transmit on my other radio, an Apollo SL60, I have no such problem. I've tried switching the antennas between the two radios, and it's still the Garmin that causes the problem. Both COM antennas are in the rear of the airplane, so the coax runs back past the pitch servo. The coax is the kind that has an extra metal shield around it. Since switching antennas didn't change the offending radio, my guess is that the problem is something else... maybe a bad ground? All avionics are in the same stack, which is firmly bolted together and also has lots of ground wires run. The GNS is farther from the A/P than is the Apollo radio. I need some suggestions on how to go about troubleshooting this arrangement... where do I start, and what are all the things I should check? I am familiar with electronics. Jim Oberst ________________________________ Message 3 _____________________________________ Time: 07:51:26 AM PST US From: "Bruce Gray" Subject: RE: AeroElectric-List: Transmitter/Autopilot interference --> AeroElectric-List message posted by: "Bruce Gray" Hi Jim, Get some copper foil tape and wrap the wire bundle that connects your pitch servo to the control unit of the STEC 55. Ground the foil on the panel unit and don't ground it on the servo. Make sure that the foil tape cobers the wire completely, from connector to connector, no breaks. The object here is to shield the servo control wires from RFI. Bruce www.glasair.org -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of J. Oberst Subject: AeroElectric-List: Transmitter/Autopilot interference --> AeroElectric-List message posted by: "J. Oberst" I have an S-TEC system 55 A/P in my Glasair Super II. When the A/P is in the vertical speed or altitude-hold mode, and I transmit on my Garmin GNS 530, the autopilot is affected and my airplane pitches down. If I transmit on my other radio, an Apollo SL60, I have no such problem. I've tried switching the antennas between the two radios, and it's still the Garmin that causes the problem. Both COM antennas are in the rear of the airplane, so the coax runs back past the pitch servo. The coax is the kind that has an extra metal shield around it. Since switching antennas didn't change the offending radio, my guess is that the problem is something else... maybe a bad ground? All avionics are in the same stack, which is firmly bolted together and also has lots of ground wires run. The GNS is farther from the A/P than is the Apollo radio. I need some suggestions on how to go about troubleshooting this arrangement... where do I start, and what are all the things I should check? I am familiar with electronics. Jim Oberst == == == == ________________________________ Message 4 _____________________________________ Time: 08:26:22 AM PST US From: "Paul Schattauer" Subject: RE: AeroElectric-List: Transmitter/Autopilot interference --> AeroElectric-List message posted by: "Paul Schattauer" S TEC has a new aluminum pitch transducer that eliminates this problem. RF was apparently getting into the pitch transducer when transmitting. Paul >From: "J. Oberst" >Reply-To: aeroelectric-list@matronics.com >To: >Subject: AeroElectric-List: Transmitter/Autopilot interference >Date: Thu, 9 Sep 2004 09:23:35 -0500 > >--> AeroElectric-List message posted by: "J. Oberst" > > >I have an S-TEC system 55 A/P in my Glasair Super II. When the A/P is in >the vertical speed or altitude-hold mode, and I transmit on my Garmin GNS >530, the autopilot is affected and my airplane pitches down. If I transmit >on my other radio, an Apollo SL60, I have no such problem. I've tried >switching the antennas between the two radios, and it's still the Garmin >that causes the problem. > >Both COM antennas are in the rear of the airplane, so the coax runs back >past the pitch servo. The coax is the kind that has an extra metal shield >around it. Since switching antennas didn't change the offending radio, my >guess is that the problem is something else... maybe a bad ground? All >avionics are in the same stack, which is firmly bolted together and also >has lots of ground wires run. The GNS is farther from the A/P than is the >Apollo radio. > >I need some suggestions on how to go about troubleshooting this >arrangement... where do I start, and what are all the things I should >check? I am familiar with electronics. > >Jim Oberst > > ________________________________ Message 5 _____________________________________ Time: 08:43:30 AM PST US From: "Bruce Gray" Subject: RE: AeroElectric-List: Transmitter/Autopilot interference --> AeroElectric-List message posted by: "Bruce Gray" Great! Another electronic gizzmo that I have to upgrade. Bruce www.glasair.org -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Paul Schattauer Subject: RE: AeroElectric-List: Transmitter/Autopilot interference --> AeroElectric-List message posted by: "Paul Schattauer" S TEC has a new aluminum pitch transducer that eliminates this problem. RF was apparently getting into the pitch transducer when transmitting. Paul ________________________________ Message 6 _____________________________________ Time: 08:47:49 AM PST US From: "Robert L. Nuckolls, III" alternators/generators Subject: RE: AeroElectric-List: Turboprop and rocket engine alternators/generators --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" alternators/generators At 10:59 PM 9/8/2004 -0500, you wrote: All the turbine powered aircraft I've worked on have gear driven starter-generators. The only exception is our new Horizon that has separate starters and wild-frequency AC alternators. Here's a typical starter-generator installation on a Pratt-Whitney turbofan: http://www.aeroelectric.com/Pictures/typical_SG_Installation.jpg For over 30 years, there's been a tantalizing notion of one-piece starter generators for piston aircraft . . . we studied the idea several times at Electromech decades ago. For then and for the moment, separate devices is still the low cost of ownership, lowest weight combination for the piston engine aircraft. Interestingly enough, turbines are moving AWAY from the one-piece idea and toward separate starting and power generation devices. I've heard that there are some miniature turboshaft engines that are easy to start with electrics or air that are being used to crank the very large turbo-fan engines. Wild-frequency AC is becoming the generation technology of choice for power-hungry aircraft . . . Bob . . . >--> AeroElectric-List message posted by: "Pete & Farrell Rouse" > > >To All, > >The accessory gear case of the turbine engine is where the starter and other >accessories are located. On the TFE731, the starter is a starter/generator >and does double duty. > >The accessory gear case is usually driven off of the high speed spool. On >most engines that I've worked on, it is located at the bottom of the engine, >just behind the fan case or particle separator. > >Turbofan engines use electric and air turbine starters; each has its own >drawbacks. I have spent many a day trying to figure out what the start >system was doing on the engine I was working on.... > >Pete Rouse >-----Original Message----- >From: owner-aeroelectric-list-server@matronics.com >[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Matt >Prather >To: aeroelectric-list@matronics.com >Subject: Re: AeroElectric-List: Turboprop and rocket engine >alternators/generators > >--> AeroElectric-List message posted by: "Matt Prather" > >It strikes me that I have seen both gear and belt driven alternators >on gas turbine/turboprops. I assume the same can be said of turbofans >and turbojets, but at the moment, I can't visualize where the power >takeoff would be located. It can't be too hard since they use electric >motors to spool up. > >Regards, > >Matt- >VE N34RD, C150 N714BK > > > --> AeroElectric-List message posted by: sjhdcl@kingston.net > > > > Bob, > > > > Can you point me in a direction to find out more about alternator and > > generator applications on turboprops, jets, rocket propulsion, etc. > > > > A typical reciprocating engine has a belt driven or geared alternator > > onboard. Specically I'm looking for info on how rocket engines produce > > the required electrical needs and backups. > > > > Thank you > > Steve > > RV > > > > > > >--- >Version: 6.0.752 / Virus Database: 503 - Release Date: 9/3/2004 Bob . . . -------------------------------------------------------- < Throughout history, poverty is the normal condition > < of man. Advances which permit this norm to be > < exceeded -- here and there, now and then -- are the > < work of an extremely small minority, frequently > < despised, often condemned, and almost always opposed > < by all right-thinking people. Whenever this tiny > < minority is kept from creating, or (as sometimes > < happens) is driven out of a society, the people > < then slip back into abject poverty. > < > < This is known as "bad luck". > < -Lazarus Long- > <------------------------------------------------------> http://www.aeroelectric.com --- ________________________________ Message 7 _____________________________________ Time: 10:52:16 AM PST US From: "Bobby Hester" Subject: Re: Re: AeroElectric-List: Contactor Torque --> AeroElectric-List message posted by: "Bobby Hester" This info is straight off http://www.wicksaircraft.com/catalog/product_cat.php/subid=2101/index.html Maximum torque requirements: 10-32 threaded studs 15 in/lb., 5/16-24 threaded studs - 35 in/lbs. Do NOT over torque. > -----Original Message----- > From: "Robert L. Nuckolls,III" > To: aeroelectric-list@matronics.com > Date: Wed, 08 Sep 2004 22:21 (CDT) > Subject: Re: AeroElectric-List: Contactor Torque > > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > At 06:16 PM 9/8/2004 -0400, you wrote: > > >--> AeroElectric-List message posted by: "DAVID REEL" > > > >I've seen a number of messages regarding ruining the cole-Hersee > >contactors by over-torque but the messages never state a correct > >torque. Presuming one holds the bottom nut to prevent rotating the > >terminal, what would be the torque to apply? The terminals are 5/16-24 > >thread but are not cadmium plated & who knows what metal is being > >used. Looks like copper on the one I got from Vans. Cole-Hersee hasn't > >replied to my emails so I'm wondering if someone on the list knows. > > "Over torque" of the threads isn't the biggest risk, it's twisting > the studs in their plastic insulators. You can avoid this with > the two-wrench approach to tightening. You need to counter-torque > the nut next to the housing while tightening the top nut down on > the terminals. The studs are hard copper. AC43-13 calls out 60-85 > inch-pounds for 24,000 psi steel bolts. 50-60 in-lb would be fine > for the contactor studs . . . which is not a lot of force at the > end of a 12" wrench . . . about 5 pounds. Your nut should have > an internal tooth, phosphor-bronze or beryllium-copper lockwasher > under it. > > Bob . . . > > > --- > > > > > > > ------- Surfing the web from Hopkinsville, KY RV7A web site: http://www.geocities.com/hester-hoptown/RVSite ________________________________ Message 8 _____________________________________ Time: 12:45:44 PM PST US From: "DAVID REEL" Subject: Re: AeroElectric-List: Got Lockwasher? --> AeroElectric-List message posted by: "DAVID REEL" >--> AeroElectric-List message posted by: "DAVID REEL" > >I need one switch locking washer, you know, the kind with tabs that >prevent switch rotation in the mounting hole, to complete my panel >installation. If anyone out there bought a dozen when they were in the >same situation & could mail me one, drop me an email & I'll send you back >a buck. If you can't put your hands on one . . . B&C stocks them and would probably drop one in an envelope to you for the price of a phone call. Bob . . . Well, I tried it & they did. Great folks. Dave Reel - RV8A ________________________________ Message 9 _____________________________________ Time: 02:48:25 PM PST US From: "DAVID REEL" "rvlist" Subject: AeroElectric-List: Making neat cable runs --> AeroElectric-List message posted by: "DAVID REEL" I just realized why I'm having trouble making my cable runs into neat bundles. All my ground wires are a little short! :) Do Not Archive Dave Reel - RV8A