---------------------------------------------------------- Zenith-List Digest Archive --- Total Messages Posted Wed 02/20/08: 26 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:06 AM - AeroElectric Connection Manual for sale (John Davis) 2. 06:55 AM - Re: Sabrina Re: pitching the H-stab (Jim McBurney) 3. 07:06 AM - Re: XL WING BOLTS?? (Jim McBurney) 4. 07:37 AM - More Fuel (Zill Coleman) 5. 07:43 AM - Re: Re: 701 motor mount attach points on firewall (Jerry Hey) 6. 07:44 AM - Re: XL WING BOLTS?? (Bryan Martin) 7. 07:51 AM - Re: Torque values (txpilot) 8. 08:13 AM - Re: Zenith-List Digest: 29 Msgs - 02/19/08 (kensmith@springnet1.com) 9. 08:35 AM - Re: More Fuel (Jeyoung65@aol.com) 10. 08:47 AM - XL WING BOLTS and any bolts. (Beckman, Rick) 11. 10:13 AM - Re: AeroElectric Connection Manual for sale (Bob Sturgis) 12. 11:11 AM - Re: More Fuel (LarryMcFarland) 13. 11:37 AM - Re: Re: Zenith-List Digest: 29 Msgs - 02/19/08 (Bryan Martin) 14. 12:05 PM - Re: XL WING BOLTS and any bolts. (Bryan Martin) 15. 02:09 PM - Re: Diesel engines (dalemed) 16. 02:26 PM - Re: Sabrina Re: pitching the H-stab (n801bh@netzero.com) 17. 02:31 PM - 601XL Canopy (aprazer) 18. 02:44 PM - Re: 601XL Canopy (Bryan Martin) 19. 03:14 PM - I m spreading the news. (steve) 20. 03:21 PM - Re: 601XL Canopy (Craig Payne) 21. 05:43 PM - Rudder cut-out (Bill Naumuk) 22. 06:07 PM - Re: I m spreading the news. (cookwithgas) 23. 06:18 PM - Re: I m spreading the news. (Ron Lendon) 24. 07:12 PM - Re: Re: Torque values (David Downey) 25. 07:14 PM - Upholstery sources (Paul Riedlinger) 26. 07:22 PM - Re: XL WING BOLTS and any bolts. (David Downey) ________________________________ Message 1 _____________________________________ Time: 06:06:00 AM PST US From: John Davis Subject: Zenith-List: AeroElectric Connection Manual for sale Hi All, I have a brand new extra copy of Bob Nuckolls Aeroelectric Connection Manual Revision 11 which I am selling for $30 including priority mail shipping in the US. Please let me know if you are interested. Thanks, John Davis Burnsville, NC 601XL QB - Jab 3300 ________________________________ Message 2 _____________________________________ Time: 06:55:55 AM PST US From: "Jim McBurney" Subject: Re: Zenith-List: Sabrina Re: pitching the H-stab Hi, Ben, Have you considered adjusting the flap pushpull tube to position the flaperons to give you that little bit that gives you the "sweet spot" pitch attitude and the 4 mph? Seems to me that would be your best "no-flap" setting. Blue skies and tailwinds Jim CH-801 DeltaHawk diesel Augusta GA 90% done, 90% left ________________________________ Message 3 _____________________________________ Time: 07:06:08 AM PST US From: "Jim McBurney" Subject: Re: Zenith-List: XL WING BOLTS?? Hi, Bryan, Rather than leaving out the washer under the bolt-head, a better way to get proper thread exposure is to use thin washers, i.e., AN-960-516L. The washer under the bolt-head serves as a bearing during tightening as well as a spacer. Blue skies and tailwinds Jim CH-801 DeltaHawk diesel Augusta GA 90% done, 90% left ________________________________ Message 4 _____________________________________ Time: 07:37:16 AM PST US Subject: Zenith-List: More Fuel From: "Zill Coleman" My 601HDS has two 10 gallon leading edge fuel tanks. I want to add 3-5 gallons fuel capacity. Will have the wing skins off. Any suggestions? HDS 235L2C ________________________________ Message 5 _____________________________________ Time: 07:43:43 AM PST US From: Jerry Hey Subject: Re: Zenith-List: Re: 701 motor mount attach points on firewall John, thanks. That helps a lot. I notice that you have installed 7F7-5 firewall stiffeners at an angle instead of vertical. Does that have to do with the Rotax installation? One last question, what is the capacity of the Rotax oil tank? Thanks again, Jerry > > Jerry: > I've attached a picture of the left side of my 912 ring mount. You > can see the tab sticking out to the left where it will be bolted to > the firewall. The bolt goes through the firewall and through a bent > steel plate in back which also bolts into the flange of the > firewall. Presumably whatever mount you're building could be > attached the same way. > > Incidentally, the previous 912 bed-mount mounts a little differently > right here. The mount tab sticks up rather than to the left, so it > overlaps on top of 7F7-1SP. That way the bolt goes through 7F7-1SP > as well, which seems a little more durable to me. > > Hope that helps. Drop me an email offline if not, or give Zenith a > call. > > John > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=165154#165154 > > > Attachments: > > http://forums.matronics.com//files/dscf1488_142.jpg > > ________________________________ Message 6 _____________________________________ Time: 07:44:52 AM PST US From: Bryan Martin Subject: Re: Zenith-List: XL WING BOLTS?? As long as the bolt isn't turned while tightening the nut, a washer isn't really needed under the bolt head, just under the nut. You need a washer under a bolt head when tightening a bolt into a threaded hole. It is a bit simpler to use the same size bolt for all twelve locations though, especially when you're practically standing on your head in the cabin and working by feel. I put the bolts in from the back of the spar with the nuts exposed on the front side for ease of inspection. I had to drill a couple of access holes through the seat pan to allow the bolts to be inserted that way. > > > > Hi, Bryan, > > Rather than leaving out the washer under the bolt-head, a better way > to get > proper thread exposure is to use thin washers, i.e., AN-960-516L. The > washer under the bolt-head serves as a bearing during tightening as > well as > a spacer. > > Blue skies and tailwinds > -- Bryan Martin N61BM, CH 601 XL, RAM Subaru, Stratus redrive. do not archive. ________________________________ Message 7 _____________________________________ Time: 07:51:11 AM PST US Subject: Zenith-List: Re: Torque values From: "txpilot" Brad, Getting back to the original subject, page 7-301 of AC 43.13-1B shows proper torque values. Yes, they are based on shank size, not wrench size. I have this page posted on my workbench as I seem to refer to it almost every day. As opposed to a torque wrench you'd find at Home Depot, I strongly recommend taking the plunge and buying a quality torque wrench. I have one from US Tool - model TP349 and it's great. If you're planning on installing a Rotax, You'll definitely use the metric (Newton-meter) side for your engine work. I know it's expensive, but IMHO it is a must-have. Here is their website: http://www.ustool.com/ That's my two cents. Dan Ginty N787DG 90% complete Read this topic online here: http://forums.matronics.com/viewtopic.php?p=165215#165215 Attachments: http://forums.matronics.com//files/tp349_torque_wrench_199.jpg ________________________________ Message 8 _____________________________________ Time: 08:13:36 AM PST US From: "kensmith@springnet1.com" Subject: Zenith-List: Re: Zenith-List Digest: 29 Msgs - 02/19/08 Subject: Re: Zenith-List: Sabrina Re: Pitching the H-Stab. Two changes to the aircraft by changing the pitch to the H-Stab has not yet been addressed. #1 - People in the agriculture spraying business sometimes increase the up pitch to the H-Stab because they have a out of aft CG when fully loaded. The tail assembly on an aircraft helps the loading and CG of the aircraft's stability in the flying mode. When you increase the angle of attack on the H-Stab you increase the loading on the tail section of the aircraft which in turn decreases some of the loading on the main wing spar section. Reduce the main wing loading and you will reduce the stall speed of the aircraft. #2 - If you reduce the angle of attack of the H-Stab, just the opposite will occur. You have reduced the loading to the tail section and in turn increased the loading on the main wing spar section. You have then made the aircraft a less stable as well as you have increased the STALL SPEED of your aircraft. Ken Smith Time: 12:29:31 AM PST US >From: Bryan Martin >Subject: Re: Zenith-List: Sabrina Re: pitching the H-stab > >The stabilizer has little to do with the cruise flight attitude of the >fuselage, it mainly has to do with the trim condition of the airplane. >If you can trim out the elevator forces in cruise without excessive >trim tab deflection, re-pitching the stabilizer won't help you. I re- >pitched my stabilizer because I couldn't trim out the stick forces, >not because the attitude of the airplane was wrong. I had to hold back >pressure on the stick all the time to keep the plane from diving. > >The cruise flight attitude of the fuselage is controlled mainly by the >angle of incidence of the main wing. Increasing the angle of incidence >of the main wing will bring the nose of the fuselage down, but then >you will also have to pitch the stabilizer up to get it back into trim. > >On Feb 19, 2008, at 1:26 AM, NYTerminat@aol.com wrote: > > > >>Hi all, >> >>With all the talk of pitching the horizontal stabilizer lately I >>have a quick question. I am doing my conditional inspection on my >>701 and decided to replace the front horizontal stabilizer brackets >>to the .063 material. There were no cracks in my old ones but I >>figured I might as well bite the bullet now while the weather is >>keeping me from flying anyway. I have always felt that I was flying >>in a nose high attitude while at cruise and that I do not see the >>higher MPH that others see. I purchased a digital level and have >>discovered that my horizontal stabilizer was about a half of a >>degree low in the front (approx 3 mm). I plan on raising it one >>degree so that I will be a half of a degree higher in the front >>based on the A-E line. I am wondering if this is a good idea as I >>believe this will get me flying in a better attitude at cruise and >>pick up some speed. Any thoughts? >> >>Bob Spudis >>N701Zx/ CH-701/ 912S/ 140hrs >> >> >> >> > > > > ________________________________ Message 9 _____________________________________ Time: 08:35:43 AM PST US From: Jeyoung65@aol.com Subject: Re: Zenith-List: More Fuel Why not add the wing baggage comp. fuel tanks? Jerry of Ga In a message dated 2/20/2008 10:38:26 A.M. Eastern Standard Time, zill@pinnacletrans.com writes: My 601HDS has two 10 gallon leading edge fuel tanks. I want to add 3-5 gallons fuel capacity. Will have the wing skins off. Any suggestions? HDS 235L2C **************Ideas to please picky eaters. Watch video on AOL Living. (http://living.aol.com/video/how-to-please-your-picky-eater/rachel-campos-duffy/ 2050827?NCID=aolcmp00300000002598) ________________________________ Message 10 ____________________________________ Time: 08:47:59 AM PST US Subject: Zenith-List: XL WING BOLTS and any bolts. From: "Beckman, Rick" As long as the bolt isn't turned while tightening the nut, a washer isn't really needed under the bolt head, just under the nut. You need a washer under a bolt head when tightening a bolt into a threaded hole. It is a bit simpler to use the same size bolt for all twelve locations though, especially when you're practically standing on your head in the cabin and working by feel. I put the bolts in from the back of the spar with the nuts exposed on the front side for ease of inspection. I had to drill a couple of access holes through the seat pan to allow the bolts to be inserted that way. Brian, it's your bird and you can do it however you wish as long as you feel it is safe. My Tech Counselor, Jim Miller, Tony Bengalis award winner, told me the bolts go "In, Back, and Down". Also, the washer under the bolt head will spread the force over a slightly larger area and, should the bolt turn any, the washer will keep the hex corners from digging into the softer aluminum. Again, just my $.02. Rick Do not archive. ________________________________ Message 11 ____________________________________ Time: 10:13:32 AM PST US From: Bob Sturgis Subject: Re: Zenith-List: AeroElectric Connection Manual for sale I am interested. I am just gathering all my insterments and getting ready to wire. Bob Sturgis bobefx@yahoo.com 601xl QB 818-902-9354 work 6am - 6pm Mon to Sat. ________________________________ Message 12 ____________________________________ Time: 11:11:33 AM PST US From: LarryMcFarland Subject: Re: Zenith-List: More Fuel Hi Zill, I'd recommend you look at putting extra tanks in the wing lockers or use a small header. Larry McFarland 601HDS at www.macsmachine.com Zill Coleman wrote: > My 601HDS has two 10 gallon leading edge fuel tanks. I want to add > 3-5 gallons fuel capacity. Will have the wing skins off. Any > suggestions? > > HDS 235L2C ________________________________ Message 13 ____________________________________ Time: 11:37:09 AM PST US From: Bryan Martin Subject: Re: Zenith-List: Re: Zenith-List Digest: 29 Msgs - 02/19/08 I situation #1, in addition to the lower stall speed, the airplane has less pitch stability. If you add too much angle of attack to the stabilizer you may end up with a situation where the stabilizer, generating positive lift, can stall before the main wing. This would result in a pitch up which you may not be able to recover from. In situation #2, increasing the stall speed of the airplane does not make it less stable. Actually, decreasing the angle of attack of the stabilizer (pitching it down) INCREASES the pitch stability of the airplane. The stabilizer will be flying at a lower angle of attack than the main wing and the main wing will stall first, resulting in a pitch down towards stall recovery. The stabilizer will most likely be flying at a negative angle of attack and producing a down force on the tail. In this case, even if it stalls first, the result will be a pitch down towards stall recovery. The higher stall speed just means you will need a longer runway and faster approach speeds. Unfortunately, it also it makes an emergency landing more dangerous. On Feb 20, 2008, at 11:10 AM, kensmith@springnet1.com wrote: > > > Subject: Re: Zenith-List: Sabrina Re: Pitching the H-Stab. > > Two changes to the aircraft by changing the pitch to the H-Stab has > not yet been addressed. > > #1 - People in the agriculture spraying business sometimes increase > the up pitch to the H-Stab > because they have a out of aft CG when fully loaded. The tail > assembly on an aircraft helps the > loading and CG of the aircraft's stability in the flying mode. When > you increase the angle of attack > on the H-Stab you increase the loading on the tail section of the > aircraft which in turn decreases > some of the loading on the main wing spar section. Reduce the main > wing loading and you will > reduce the stall speed of the aircraft. > > #2 - If you reduce the angle of attack of the H-Stab, just the > opposite will occur. You have > reduced the loading to the tail section and in turn increased the > loading on the main wing spar > section. You have then made the aircraft a less stable as well as > you have increased the > STALL SPEED of your aircraft. > > Ken Smith > -- Bryan Martin N61BM, CH 601 XL, RAM Subaru, Stratus redrive. do not archive. ________________________________ Message 14 ____________________________________ Time: 12:05:38 PM PST US From: Bryan Martin Subject: Re: Zenith-List: XL WING BOLTS and any bolts. The "in, back and down" rule of thumb is based on the idea that if it's applied, the forces acting on the bolt will tend to keep it in place even if the nut falls off. It is not a hard and fast rule though, just a guideline. If there's no particular reason not to, it should be applied. In some cases, this rule can't be applied (for instance, if it doesn't allow a torque wrench to be applied to the nut) and in others, there is a good reason not to apply it. In the case of the spar bolts, I would rather be able to physically inspect the nuts before flight even if it does violate this guideline. It's also pretty difficult to get a torque wrench on the nut if it's under the seat pan. The hex corners on AN bolts are chamfered so they can't dig into the surface they are mounted to. There is a circular bearing surface built into the bolt head. On Feb 20, 2008, at 11:44 AM, Beckman, Rick wrote: > > Brian, it's your bird and you can do it however you wish > as long as you feel it is safe. My Tech Counselor, Jim Miller, Tony > Bengalis award winner, told me the bolts go "In, Back, and Down". > Also, the washer under the bolt head will spread the > force over a slightly larger area and, should the bolt turn any, the > washer will keep the hex corners from digging into the softer > aluminum. > Again, just my $.02. > Rick > -- Bryan Martin N61BM, CH 601 XL, RAM Subaru, Stratus redrive. do not archive. ________________________________ Message 15 ____________________________________ Time: 02:09:56 PM PST US Subject: Zenith-List: Re: Diesel engines From: "dalemed" You might be interested in the Gemini 100 by Powerplant Developements in England. I saw the engine at the Light Sport Expo in Florida and really like the looks and idea of it. Its 100bhp at 2500rpm and has a specific fuel consumption of 0.37 at 75%. The total installed wet weight is 190.5 lbs. That's competitive with the Jabiru 3300 or Rotax 912. You can request info at info@ppdgemini.com. -------- Dale Flying Cessna 170B Building Zenith 601XL Read this topic online here: http://forums.matronics.com/viewtopic.php?p=165270#165270 Attachments: http://forums.matronics.com//files/gemini_100_spec_sheet_12_07_910.pdf ________________________________ Message 16 ____________________________________ Time: 02:26:36 PM PST US From: "n801bh@netzero.com" Subject: Re: Zenith-List: Sabrina Re: pitching the H-stab Hi Jim.. My conditional inspection is coming up next month and that is e xactly what I am going to do, The adjustment is rather simple as all I n eed to do is slide the limit switch in the flap motor to make it stop so oner. As you being a fellow 801 builder knows we cannot change the main wing angle of incidence because the area we have to drill through for th e spar bolts is not a large enough surface to make any adjustments. Ther e will be an edge distance issue in both the front and rear spars if I a lter it. Tailwinds and do not archive Ben Haas N801BH www.haaspowerair.com -- "Jim McBurney" wrote: Hi, Ben, Have you considered adjusting the flap pushpull tube to position the flaperons to give you that little bit that gives you the "sweet spot" pi tch attitude and the 4 mph? Seems to me that would be your best "no-flap" setting. Blue skies and tailwinds Jim CH-801 DeltaHawk diesel Augusta GA 90% done, 90% left ======================== =========== ======================== =========== ======================== =========== ======================== =========== _____________________________________________________________ Improve your ability to get around with a wheel chair van. Click now! http://thirdpartyoffers.netzero.net/TGL2221/fc/Ioyw6i4sxOu5IyulikJmE0dd4 rPKSWnxHH65KbMoSw7J0wmmxfoKdM/ ________________________________ Message 17 ____________________________________ Time: 02:31:54 PM PST US Subject: Zenith-List: 601XL Canopy From: "aprazer" Ladies and Gents; I have decided to glue the broken triangular piece back onto the canopy instead of purchasing a new canopy for $550 and then go through all the trouble of trimming, drilling, etc... To cover the damaged area, I have decided to revert back to the old way of doing things by installing a metal flashing on the front of the canopy. This is where I need the help from someone! Does anyone have the dimensions for this front flashing? My plans are too new and don't show this flashing. Any and all help will be greatly appreciated. Mack N990MK CH601XL/Jabiru3300 -------- The poh-oh-unemployed farm boy from Idaho Read this topic online here: http://forums.matronics.com/viewtopic.php?p=165275#165275 ________________________________ Message 18 ____________________________________ Time: 02:44:12 PM PST US From: Bryan Martin Subject: Re: Zenith-List: 601XL Canopy I don't have my plans handy right now but you could just lay a piece of craft paper up there and trim it to fit and use that as a pattern for the metal. > > Ladies and Gents; > I have decided to glue the broken triangular piece back onto the > canopy instead of purchasing a new canopy for $550 and then go > through all the trouble of trimming, drilling, etc... > To cover the damaged area, I have decided to revert back to the old > way of doing things by installing a metal flashing on the front of > the canopy. > This is where I need the help from someone! > Does anyone have the dimensions for this front flashing? My plans > are too new and don't show this flashing. > Any and all help will be greatly appreciated. > Mack -- Bryan Martin N61BM, CH 601 XL, RAM Subaru, Stratus redrive. do not archive. ________________________________ Message 19 ____________________________________ Time: 03:14:38 PM PST US From: "steve" Subject: Zenith-List: I m spreading the news. Our fellow builder and contributior to this site, Larry McFarland has a machine shop and offers his services to this group. I saw that he had a nose wheel tow bar and strut collar for sale and I bought one from him. It arrived today..... What an " absolutely beautiful" piece of craftsmanship. The design is perfect and this product is amazing. Like most builders I thought I might build my own tow bar system, but now know that there's no way I could come close to the quality of Larry's work. I hope Larry continues to make these items and I recommend that everyone ask him about his products. Thanks Larry Steve Weston N9554Z 601XL almost, almost almost done! ________________________________ Message 20 ____________________________________ Time: 03:21:26 PM PST US From: "Craig Payne" Subject: RE: Zenith-List: 601XL Canopy My oldest set of plans lists .025, 210 X 1600, 6-C-3, 05/01. Same on the 01/03 version. -- Craig -----Original Message----- From: owner-zenith-list-server@matronics.com [mailto:owner-zenith-list-server@matronics.com] On Behalf Of aprazer Sent: Wednesday, February 20, 2008 3:29 PM Subject: Zenith-List: 601XL Canopy Ladies and Gents; I have decided to glue the broken triangular piece back onto the canopy instead of purchasing a new canopy for $550 and then go through all the trouble of trimming, drilling, etc... To cover the damaged area, I have decided to revert back to the old way of doing things by installing a metal flashing on the front of the canopy. This is where I need the help from someone! Does anyone have the dimensions for this front flashing? My plans are too new and don't show this flashing. Any and all help will be greatly appreciated. Mack N990MK CH601XL/Jabiru3300 -------- The poh-oh-unemployed farm boy from Idaho Read this topic online here: http://forums.matronics.com/viewtopic.php?p=165275#165275 ________________________________ Message 21 ____________________________________ Time: 05:43:48 PM PST US From: "Bill Naumuk" Subject: Zenith-List: Rudder cut-out All- Nearly out of airframe parts! Need some help on this. Anyone have a surefire way of cutting the rudder nose skin to fit the stab and rudder fairing? All suggestions welcome, especially from flying people. Thanks. Bill Naumuk Townville, Pa. HDS Fuse/Corvair ________________________________ Message 22 ____________________________________ Time: 06:07:57 PM PST US Subject: Zenith-List: Re: I m spreading the news. From: "cookwithgas" Steve: It is no surprise to me. I've been admiring Larry's work for years. His sheet brake plans were superb and allowed me to build a sheet brake that helped me plans-build my airplane. I'm a big Larry Mc -fan also. Scott Laughlin www.cooknwithgas.com Read this topic online here: http://forums.matronics.com/viewtopic.php?p=165317#165317 ________________________________ Message 23 ____________________________________ Time: 06:18:30 PM PST US Subject: Zenith-List: Re: I m spreading the news. From: "Ron Lendon" I'm a big Larry Mac fan also. Look at the bike I hope to bring to SnF. His plans and seat form make it all possible. I did a little work myself but "Good Design is Good Design". Thanks Larry! http://mykitlog.com/users/index.php?user=rlendon&project=441 -------- Ron Lendon, Clinton Township, MI Corvair Zodiac XL, ScrapBuilder ;-) http://www.mykitlog.com/rlendon Read this topic online here: http://forums.matronics.com/viewtopic.php?p=165322#165322 ________________________________ Message 24 ____________________________________ Time: 07:12:20 PM PST US From: David Downey Subject: Re: Zenith-List: Re: Torque values don't forget that you need a calibration check at least once a year. Before the flames start to bloom, a simple fixture with a crank arm in a bearing and a tared bucket with water in it (pure water is 1 gram/cc; 453.6 grams/pound) is a good functional check. Brad, Getting back to the original subject, page 7-301 of AC 43.13-1B shows proper torque values. Yes, they are based on shank size, not wrench size. I have this page posted on my workbench as I seem to refer to it almost every day. As opposed to a torque wrench you'd find at Home Depot, I strongly recommend taking the plunge and buying a quality torque wrench. I have one from US Tool - model TP349 and it's great. If you're planning on installing a Rotax, You'll definitely use the metric (Newton-meter) side for your engine work. I know it's expensive, but IMHO it is a must-have. Here is their website: http://www.ustool.com/ That's my two cents. Dan Ginty N787DG 90% complete Read this topic online here: http://forums.matronics.com/viewtopic.php?p=165215#165215 Attachments: http://forums.matronics.com//files/tp349_torque_wrench_199.jpg Dave Downey Harleysville (SE) PA 100 HP Corvair --------------------------------- Never miss a thing. Make Yahoo your homepage. ________________________________ Message 25 ____________________________________ Time: 07:14:58 PM PST US From: "Paul Riedlinger" Subject: Zenith-List: Upholstery sources I am at that point on my XL where I have to start thinking about interior upholstery. I would be interested in getting recommendations (or avoidance warnings) on who has the best interiors. I am partial to leather (or similar) at this point. -- Paul Riedlinger cndmovn@gmail.com ________________________________ Message 26 ____________________________________ Time: 07:22:55 PM PST US From: David Downey Subject: Re: Zenith-List: XL WING BOLTS and any bolts. unless the hole is too close to the radius in the first place... do not archive Bryan Martin wrote: The "in, back and down" rule of thumb is based on the idea that if it's applied, the forces acting on the bolt will tend to keep it in place even if the nut falls off. It is not a hard and fast rule though, just a guideline. If there's no particular reason not to, it should be applied. In some cases, this rule can't be applied (for instance, if it doesn't allow a torque wrench to be applied to the nut) and in others, there is a good reason not to apply it. In the case of the spar bolts, I would rather be able to physically inspect the nuts before flight even if it does violate this guideline. It's also pretty difficult to get a torque wrench on the nut if it's under the seat pan. The hex corners on AN bolts are chamfered so they can't dig into the surface they are mounted to. There is a circular bearing surface built into the bolt head. On Feb 20, 2008, at 11:44 AM, Beckman, Rick wrote: Brian, it's your bird and you can do it however you wish as long as you feel it is safe. My Tech Counselor, Jim Miller, Tony Bengalis award winner, told me the bolts go "In, Back, and Down". Also, the washer under the bolt head will spread the force over a slightly larger area and, should the bolt turn any, the washer will keep the hex corners from digging into the softer aluminum. Again, just my $.02. Rick -- Bryan Martin N61BM, CH 601 XL, RAM Subaru, Stratus redrive. do not archive. Dave Downey Harleysville (SE) PA 100 HP Corvair --------------------------------- ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message zenith-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Zenith-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/zenith-list Browse Digests http://www.matronics.com/digest/zenith-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.