saybeengineering Posted February 28, 2009 Share Posted February 28, 2009 My Long EZ has 914 Hours and first flight was 20 years ago. Every month I check the canard bolts and torque them because they do become loose. I decided to take them out to inspect them because one of them was not tightening enough. I'm glad I did. Look at the attached photos and you'll understand why..... I replaced them immediately. Is this pretty common??? Please inspect your canard bolts frequently for integrity..... Afif Saybe Long EZ, HR-ATQ Honduras, Central America Quote Afif Saybe Long-EZ, HR-ATQ Link to comment Share on other sites More sharing options...
TMann Posted February 28, 2009 Share Posted February 28, 2009 What about the nutplates? Quote T Mann - Loooong-EZ/20B Infinity R/G Chpts 18 Velocity/RG N951TM Mann's Airplane Factory We add rocket's to everything! 4, 5, 6, 7, 8. 9, 10, 14, 19, 20 Done Link to comment Share on other sites More sharing options...
saybeengineering Posted February 28, 2009 Author Share Posted February 28, 2009 Took one nut plate off and inspected it before introducing the new bolts and it was integral. Tried the new bolts and it fit pretty tight but I did unscrewed the bolt and checked the bolt's thread and it was AOK.... Quote Afif Saybe Long-EZ, HR-ATQ Link to comment Share on other sites More sharing options...
Terry Posted February 28, 2009 Share Posted February 28, 2009 Change the nutplates. They may look ok but there not. Use a torque wrench to tighten the bolts instead of german torque and this won't happen. Terry Quote Link to comment Share on other sites More sharing options...
saybeengineering Posted February 28, 2009 Author Share Posted February 28, 2009 Torque level???? Quote Afif Saybe Long-EZ, HR-ATQ Link to comment Share on other sites More sharing options...
Terry Posted February 28, 2009 Share Posted February 28, 2009 IAW AC43.13-1B Table 7-1. 1/4-28 (AN4-XX) bolt 50 to 70 INCH pounds (4.2 to 5.3 foot pounds) 100 INCH pounds (8.3 foot pounds) MAX. This is on the FAA.GOV web site but every one building/working on an airplane should have a paper copy. Much good stuff in there. Terry Quote Link to comment Share on other sites More sharing options...
Waiter Posted February 28, 2009 Share Posted February 28, 2009 I've been using standard self locking nuts and large area washers since day one (two large washers and a nut instead of the nut plates) Waiter Quote F16 performance on a Piper Cub budget LongEZ, 160hp, MT CS Prop, Downdraft cooling, Full retract visit: www.iflyez.com Link to comment Share on other sites More sharing options...
saybeengineering Posted February 28, 2009 Author Share Posted February 28, 2009 Thanks.....I might change for self locking nuts and the two large washers. Large, what diameter?? Quote Afif Saybe Long-EZ, HR-ATQ Link to comment Share on other sites More sharing options...
jdubner Posted February 28, 2009 Share Posted February 28, 2009 Torque level???? On page 50, my Long-EZ P.O.H. (First Edition -- May 1980) says this about the AN-4 bolts: "These bolts should be snugged well (about 30 inch/lb) but not over-tightened." That's the torque I strive for. I feel no need to use the AC43-13 max. torque spec because these bolts are in sheer. And like Waiter, I use locknuts instead of nutplates. -- Joe Quote Joe Dubner Long-EZ, RV-8A Link to comment Share on other sites More sharing options...
saybeengineering Posted February 28, 2009 Author Share Posted February 28, 2009 I changed the bolts with self locking nuts and 2 1.5" oversize washers....Work out pretty nice. Thanks Waiter!!! AFIF HR-ATQ, LONG EZ HONDURAS Quote Afif Saybe Long-EZ, HR-ATQ Link to comment Share on other sites More sharing options...
WTJohnson Posted March 1, 2009 Share Posted March 1, 2009 My Long EZ has 914 Hours and first flight was 20 years ago. Every month I check the canard bolts and torque them because they do become loose. I decided to take them out to inspect them because one of them was not tightening enough. I'm glad I did. Look at the attached photos and you'll understand why..... I replaced them immediately. Is this pretty common??? Please inspect your canard bolts frequently for integrity..... Afif Saybe Long EZ, HR-ATQ Honduras, Central America ...........I had a bolt that looked like this also a bunch of years ago. Think it was from cross threading the bolt in the nutplate. Have gone twenty years without another problem.......just make sure that the nut starts right. Mine are in the blind, so it is all feel. WTJohnson Quote Link to comment Share on other sites More sharing options...
Waiter Posted March 1, 2009 Share Posted March 1, 2009 A word of Caution when tightening the nuts, As with most bolts I use in my plane, the canard bolts have a portion of the shank that is not threaded. Always inspect the nut after its been tightened, to make sure it has not bottomed out on the shank. I have a rule of thumb that works OK for the standard AN type bolts. After I install and tighten the nut, Look at the threaded portion of the bolt that sticks out past the nut. I must see at least 1 thread, but no more that 3 thread showing. If I see less than one thread, replace the bolt with the next size longer, If I see more than three showing, replace the bolt with the next size shorter. Waiter Quote F16 performance on a Piper Cub budget LongEZ, 160hp, MT CS Prop, Downdraft cooling, Full retract visit: www.iflyez.com Link to comment Share on other sites More sharing options...
saybeengineering Posted March 1, 2009 Author Share Posted March 1, 2009 I had to use a bit longer bolts to compensate for the width of the two oversize washers. The original nut plate was bent a bit from the overtightening. However, the thick washers recommended, have more area and are stronger than the original nutplate. I have to agree that this is better, more adequate way of securing the canard...Thanks for sharing your insights.... Afif HR-ATQ Long EZ Honduras Quote Afif Saybe Long-EZ, HR-ATQ Link to comment Share on other sites More sharing options...
goatherder Posted March 6, 2009 Share Posted March 6, 2009 Those bolts have weight bearing on the threaded portion of the bolt. The weight needs to be born on the non-threaded portion - on the smooth round surface and not on the pointy little edges of the threads. This is a general rule with a bolt in shear, no? Longer bolts, man. Quote Marc Oppelt Olympia, WA http://picasaweb.google.com/oh.u8it2 Link to comment Share on other sites More sharing options...
Marc Zeitlin Posted March 6, 2009 Share Posted March 6, 2009 Those bolts have weight bearing on the threaded portion of the bolt.No they don't. The fact that part of the threaded portion of the bolt is inside the doubler on F-22 doesn't mean that it's carrying any shear load. The weight needs to be born on the non-threaded portion - on the smooth round surface and not on the pointy little edges of the threads.It is. Think about the cross section of F-22. This is a general rule with a bolt in shear, no?Absolutely - yes. Longer bolts, man.You say this because of all of the canard attach bolts that have failed in shear over the past 33 years? :-). Using longer bolts is far more likely to result in the bolts bottoming out on the threads on whatever's on the back side (nutplate or nut) and then being in bending rather than single shear on the front side, leading to far higher stresses and breakage. Fixing perceived (but ephemeral) problems by introducing new failure modes is not a good idea. Quote Marc J. Zeitlin Burnside Aerospace marc_zeitlin@alum.mit.edu www.cozybuilders.org copyright © 2024 Link to comment Share on other sites More sharing options...
goatherder Posted March 8, 2009 Share Posted March 8, 2009 Nope - I say this because I'm an ignorant n00b. I just saw bolts with the threads hammered out, understood that those bolts hold the front wing on the plane and went WTF??? So...uh, never mind. Forget I said anything. (he slinks away with his tail between his legs) Quote Marc Oppelt Olympia, WA http://picasaweb.google.com/oh.u8it2 Link to comment Share on other sites More sharing options...
chasingmars Posted March 8, 2009 Share Posted March 8, 2009 So...uh, never mind. Forget I said anything. (he slinks away with his tail between his legs) Don't slink too far, we've all been new before, and most of us didn't fess up as quickly as you when we realized it... Quote Craig K. Cozy IV #1457 building chapter seven! http://www.maddyhome.com/canardpages/pages/chasingmars/index.html Link to comment Share on other sites More sharing options...
Marc Zeitlin Posted March 8, 2009 Share Posted March 8, 2009 Nope - I say this because I'm an ignorant n00b.Ignorance, unlike some other maladies manifested by folks on occasion, is easily remedied by learning :-). I just saw bolts with the threads hammered out, understood that those bolts hold the front wing on the plane and went WTF???The picture of those bolts at the top of this "thread" (pun intended) shows bolt threads that have been stripped by continual and repetitive overtightening in a hardened nut/nutplate. If they had been beaten up by shear loads on the threads, they would not be evenly worn around the circumference - the waring would be directional. Had you asked "would longer bolts have fixed this issue?" rather than stated "Those bolts have weight bearing on the threaded portion of the bolt" and "longer bolts, man", then being a noobie would have presented an opportunity to reduce the ignorance, rather than an opportunity to slink away :-). Quote Marc J. Zeitlin Burnside Aerospace marc_zeitlin@alum.mit.edu www.cozybuilders.org copyright © 2024 Link to comment Share on other sites More sharing options...
goatherder Posted March 8, 2009 Share Posted March 8, 2009 If they had been beaten up by shear loads on the threads, they would not be evenly worn around the circumference - the waring would be directional. Maybe so. I have seen bolts in shear secured with self-locking nuts (nylocs) that have loosened due to vibration but not to the point that the nuts were gone. Just a bit loose...and then the vibration can rotate the bolt shaft and hammer the sh!t out it the same time. One example that comes to mind would be the replaceable hardened steel shoes on the bottom of a trawl door. The door, which can weigh 5 or 6 tons, slides along the seabed on these shoes, like a sled runner. The replaceable sections are about 2ft long each, made of 2" high strength steel, and are bolted to the bottom of the door with 1" bolts in shear. We secure them with nylocs, sometimes double nuts, some times welded nuts...but no matter what the stress and pounding loosens them up and they start working. If we don't catch it the relative motion will take the bolts out out in short order, and then that section will be lost. But hey...I got off on a tangent. We're talking about planes here, and all I really know about is boats. Quote Marc Oppelt Olympia, WA http://picasaweb.google.com/oh.u8it2 Link to comment Share on other sites More sharing options...
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