N201MKTurbo Posted February 6, 2020 Report Posted February 6, 2020 My plane was caught in a t storm at KTUS, it tore the chains out of the ground! The plane traveled over 100 yards and was stopped by a king air. I found no damage to the Mooney. It scratched the paint on the king airs prop. They made me fill out a police report because the Mooney scratched the King Air. I never heard anything more about it. 1 Quote
Vance Harral Posted February 6, 2020 Report Posted February 6, 2020 1 hour ago, PT20J said: Those are Huck bolts. Hmm... after a little research, looks like these are serious chore to remove, and require a special tool to re-install. I can see why they're great fasteners for this sort of application, but obviously not designed for R&R: Nerd video showing super high-tech installation: https://www.youtube.com/watch?v=W62ZJzePjAk Redneck video showing removal: https://www.youtube.com/watch?v=pP4aoLa2eJk Quote
Guest Posted February 6, 2020 Report Posted February 6, 2020 I don’t know if there is enough room in the corner of the fitting for the nut. The nut for a 5/16-18 bolt is 1/2” across the flats, you may have to grind one flat a bit narrower to make room. Clarence Quote
chriscalandro Posted February 7, 2020 Report Posted February 7, 2020 (edited) Mine ended up being the ring itself was stripped, I got the laser jack and tie down part. I got lucky. My plane was to grind down a bit and use that. consider that a helicoil requires permanent modification to the airplane. The nut requires modification of a removable nut. Which one would you prefer? Edited February 7, 2020 by chriscalandro Quote
Hank Posted February 7, 2020 Report Posted February 7, 2020 1 hour ago, chriscalandro said: consider that a helicoil requires permanent modification to the airplane. The nut requires modification of a removable nut. Which one would you prefer? Helicoils are standard repairs. I use them at work to carry much larger loads, full time, when mounting bolts holes strip out. Quick, easy, durable and easily replaceable when needed. 1 Quote
chriscalandro Posted February 7, 2020 Report Posted February 7, 2020 2 minutes ago, Hank said: Helicoils are standard repairs. I use them at work to carry much larger loads, full time, when mounting bolts holes strip out. Quick, easy, durable and easily replaceable when needed. I don’t disagree. It’s a simple, easy, normal thing. I just think the nut is a little more practical and easier. I don’t think either is wrong. Quote
PT20J Posted February 7, 2020 Report Posted February 7, 2020 1 hour ago, chriscalandro said: consider that a helicoil requires permanent modification to the airplane. The nut requires modification of a removable nut. Which one would you prefer? I would prefer the helicoil. It takes less time to install and doesn’t have to be undone to insert a jack point. Also, if the nut requires grinding to make it fit, you have to make sure you grind it enough to clear the radius in the angle bracket so as not to create a stress riser and then who knows how much you weakened it. Why go to all that trouble when there is a standard way to fix it. And, a helicoil is not a “modification”; it’s an approved repair method. 1 Quote
chriscalandro Posted February 7, 2020 Report Posted February 7, 2020 If you go with the lasar option the tie down ring and jackpoint are the same part. (The ring is part of the jackpoint) and never needs to be removed. I don’t know if that influences you’re decision but it’s something to think about. Quote
RLCarter Posted February 7, 2020 Report Posted February 7, 2020 +1 for the Heli-Coil, quick and easy..... Quote
carusoam Posted February 7, 2020 Report Posted February 7, 2020 Forever planes probably don’t get the luxury of changing out the part... 1) the hole is so close to the vertical edge... the threads of the bolt have removed the paint... see the picture... 2) Helicoils are a normal thread replacement technique for missing threads... 3) Huckbolts are wicked strong... they hold the tail hinge in place. Several long bodies had a unique AD to replace some faulty huckbolts... 4) The maintenance shop at my home drome had done the tail hinge work of an Acclaim... So.. a non MSC is capable of R&R the part if desired... 5) Tie-down Wackiness... steel bolts in aluminum threads are not a very good Century long lasting idea... the wear each time might benefit by using a thread lube...(?) Lubing threads may allow the rings to fall out... 6) Combination tie-down and jack points make a lot of sense... and some blue thread lock to hold it in place for a long temporary time... 7) More tie-down wackiness... the original steel eye-bolts have probably rusted, making them really good at cutting the aluminum threads... 8) real tie-down wackiness... A new 2 him C152 was in the tie down area... doing a run-up in place seemed to make sense... holding the brakes didn’t make enough sense... when the rope broke, the plane spun around the remaining tie-down...what was left of the C152 didn’t matter if it had ripped the tie-down bolt out... 9) Get a quote for R&R the huck bolts... just to find out... 10) Get a quote to put a heli-coil in... just because it makes sense... a mechanic can probably order a proper one with the proper strength... 11) Get SS hardware when you are done... this way the dissimilar metals won’t include rust in the combination... 12) If you are stuck at the tie-down... and adding more throttle seems to make sense... time to get out and look... (know that it will happen to everyone) no harm, no foul, to get out and look... PP summary of what I think I read above... Best regards, -a- 1 Quote
Vance Harral Posted February 7, 2020 Report Posted February 7, 2020 I don't have much experience with helicoils. What holds the helicoil in place? A quick web search suggests it's either the snapped-off edge of the tang (seems very weak), or that you can "glue" it in with thread locker. This might not be an issue with bolts that are installed once in a blue moon, but if you're R&R'ing tie down rings every time you need to jack the airplane, you want the helicoil to stay firmly in place through lots of cycles. Quote
carusoam Posted February 7, 2020 Report Posted February 7, 2020 Vance, essentially they are a device that can be installed in the hole... First the hole may need to be drilled slightly larger... Then the insert gets installed in the hole... The insert has the original threads to match what used to be in the hole... When the insert gets installed... expect the red locktite is used to permanently hold it in place... http://www.helicoil.in There are many styles of helicoil selecting the right one is a mechanic’s job... One of the places these things get used often... exhaust headers bolted to an engine... if you ever have to take exhaust headers off an engine, the threads are often destroyed in the process... similar challenge with Lycoming / Continental exhaust parts... I’m only a PP, not a mechanic... trying to illustrate a possible solution that has been described above... Best regards, -a- Quote
Guest Posted February 7, 2020 Report Posted February 7, 2020 4 hours ago, Vance Harral said: I don't have much experience with helicoils. What holds the helicoil in place? A quick web search suggests it's either the snapped-off edge of the tang (seems very weak), or that you can "glue" it in with thread locker. This might not be an issue with bolts that are installed once in a blue moon, but if you're R&R'ing tie down rings every time you need to jack the airplane, you want the helicoil to stay firmly in place through lots of cycles. The helicoil is larger in diameter than the hole it’s going into. A pre-winder shrinks it down to the correct diameter while it is being screwed in place. Friction holds it in place. Once installed, the drive tang is removed allowing the shank of the fastener to pass through. If the Helicoil becomes damaged it can be easily removed and replaced. Everyone’s spark plugs are secured in a Helicoil and they seldom fail. Clarence Quote
EricJ Posted February 7, 2020 Report Posted February 7, 2020 The helicoil is larger than the original hole so that the old bolt/fastener will fit inside it. So the hole has to be drilled out to fit the helicoil, and then the hole tapped so that the helicoil can be wound in and will hold. In an aluminum base this is stronger than the original hole since the new hole is larger with more thread area to grip the helicoil, and the helicoil is steel instead of aluminum, so it will hold the fastener better. As Clarence mentioned, for this reason, and others, spark plug holes in aluminum heads on aircraft engines typically have a helicoil in them for better strength and to reduce the likelihood of seizing. One of my wing tie-downs has a helicoil in it. I noticed it sticking up a little bit inside when I had the inspection plate off once. Not a big deal. It's actually stronger than the original joint. 1 Quote
Hank Posted February 7, 2020 Report Posted February 7, 2020 6 hours ago, Vance Harral said: I don't have much experience with helicoils. What holds the helicoil in place? A quick web search suggests it's either the snapped-off edge of the tang (seems very weak), or that you can "glue" it in with thread locker. This might not be an issue with bolts that are installed once in a blue moon, but if you're R&R'ing tie down rings every time you need to jack the airplane, you want the helicoil to stay firmly in place through lots of cycles. We use helicoils at work, in holes that mount molds up to 9000 lbs into injection molding machines. Typical runs are 3-5 days before taking the mold out and installing a different one, but can be as often as one shift. A single helicoil will last for years this way if not abused (approx. 1/2 or 5/8 inch bolts; our tie downs are 5/16, I think). So don't worry about wearing out a helicoil "every time you need to jack the airplane," even if you feel the need to jack your airplane after every flight to take the load off of your shock discs. 1 Quote
tigers2007 Posted February 7, 2020 Report Posted February 7, 2020 3 minutes ago, Hank said: even if you feel the need to jack your airplane after every flight to take the load off of your shock discs. Do people actually do this? 1 Quote
Hank Posted February 7, 2020 Report Posted February 7, 2020 11 minutes ago, tigers2007 said: Do people actually do this? No idea, but that would be the most often a Mooney would be jacked up, and frequent jacking (?) was given as a point of worry for a helicoil. Quote
carusoam Posted February 7, 2020 Report Posted February 7, 2020 Fun economics... One could save a lot of donuts by taking the weight off of them while the plane is parked... But... By the time you have amassed a convenient jacking method to be safely used each time... The few dozen donuts you have saved over your lifetime, will look pretty inconsequential.... Compared to all the other costs... Then again, you may find another failure mode if you are the only one storing your plane this way... PP thoughts only, thankful for all the shared experience found in this thread... Best regards, -a- 1 Quote
Vance Harral Posted February 7, 2020 Report Posted February 7, 2020 11 minutes ago, carusoam said: But... By the time you have amassed a convenient jacking method to be safely used each time... The few dozen donuts you have saved over your lifetime, will look pretty inconsequential.... Compared to all the other costs... At the rate those shock disks are inflating every year, I'm not so sure. When we bought our airplane 16 years ago, those things were about $70 apiece. Latest price is about double that, see https://www.skygeek.com/j11968-14.html. So a full replacement of all 11 disks in 2020 dollars is over $1500 just for the parts. Throw in a few hours of labor and the specialty tools you're supposed to use for the job, and you're looking at a $2K expense every 5-10 years depending on your model and climate. I'm a Mooney fan, obviously, but if there were an STC to install oleo struts I'd certainly consider it. The idea of storing your airplane on the jacks strikes me as only about 90% of a joke. 1 Quote
tigers2007 Posted February 7, 2020 Report Posted February 7, 2020 So that's a 6.25% increase per year over the last 16 years for parts. I really wonder how much of a physical difference it actually makes to the disks. Aren't they under some sort of compression regardless if suspended in the air? Maybe Sabre can get a STC for $19 Monroe Gasmatic's. Even with the required 20x markup it would be a steal. Quote
EricJ Posted February 7, 2020 Report Posted February 7, 2020 (edited) 2 hours ago, tigers2007 said: Do people actually do this? Probably not, but unscrewing and removing the tie down ring before flight is in the POH for a J. Edited February 7, 2020 by EricJ Quote
Ragsf15e Posted February 7, 2020 Report Posted February 7, 2020 2 minutes ago, EricJ said: Probably not, but unscrewing and removing the tie down ring before flight is in the POH for a J. That’s how they got it over the hump from 200mph to 201mph! 1 2 Quote
tmo Posted February 7, 2020 Report Posted February 7, 2020 (edited) 1 hour ago, Vance Harral said: The idea of storing your airplane on the jacks strikes me as only about 90% of a joke. I've seen cars stored on jacks... Granted this was usually classic cars in the winter, with the associated salt on roads and otherwise harsh conditions, but yeah... My late grandfather stored his "daily" driver like that for the winter, too - he even made special "stools". We didn't use to drive much, you see, and a bicycle was usually much more convenient than a car in the country, and public transportation in the cities. Oh, not that long ago (1980s) car gasoline (leaded, of course) was rationed, too... Edited February 7, 2020 by tmo 1 Quote
Vance Harral Posted February 7, 2020 Report Posted February 7, 2020 4 hours ago, EricJ said: In an aluminum base this is stronger than the original hole since the new hole is larger with more thread area to grip the helicoil, and the helicoil is steel instead of aluminum, so it will hold the fastener better. As Clarence mentioned, for this reason, and others, spark plug holes in aluminum heads on aircraft engines typically have a helicoil in them for better strength and to reduce the likelihood of seizing. It's obvious from some reading that steel helicoils are inserted into aluminum structures all the time. But isn't this a galvanic corrosion risk? Quote
ArtVandelay Posted February 7, 2020 Report Posted February 7, 2020 It's obvious from some reading that steel helicoils are inserted into aluminum structures all the time. But isn't this a galvanic corrosion risk? You’d have to use a primer to protect the metals, or you can buy ones that are already coated.Sent from my iPad using Tapatalk Quote
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