How to Tighten Flare Nuts on Experimental Aircraft

Tightening flare nuts properly for fuel, oil and hydraulic lines on experimental aircraft is important for leak free, reliable connections. We explore finding the proper torque values and techniques for setting the torque on the popular AN818 nuts. The type of material used for the tube flare holds the key for determining proper torque values.

[@Rich-ic8wl]

Great video....really appreciate the 90 degree rule!

[@gilkennedy7638]

You are one of the best I have seen to explain things.

[@arodroz]

Thank you very much. This will help me a lot. I was not aware for 90 degrees left or right.

[@perrycorn2789]

I found that a lot of engineers in aviation with installing screws bolts and other fittings they tighten them to tight especial screws holding panels on they use screws to long and over tighten the screws and this destroys the anchor nut over time and streaches the screw threads and when you go to replace the panel you have to change the screws and the anchor nuts and I show them take the screws till it bottoms and just nip maybe a 1,/8 of a turn the acchor nut will hold it and when putting panels on short screws as I have seen cables snap from long screws and bolt if you are not sure of read the manual

[@spencer4630]

Never knew the name of that tool, just ordered a set! Thank you!

[@noelthomas6357]

Dear HomebuiltHELP, I wanted to say that I love your videos. This one was as usual very helpful.

[@tedstriker754]

I found my kit included 6061T6 tubing for hydraulic, brake and fuel lines. Also if the tubing connects to the fitting at any amount of angle and not straight into it, it will leak. Small amounts of misalignment you can sometimes stop leaks with del seals.

[@louisrosner7902]

Just discovered you. Your videos are so well done and Have already been so helpful in building my Sport Performance Panther. Keep up the great work. I’m going to keep watching

[@experimental_av]

this is super helpful, thank you. I'd like to see a manual to to torque in those AN elbows, keeping to torque values but also achiving the right orientation.

[@BuddyR]

Very Nice Video , I also was not aware of the 90 degree L/R +/- 1" problem with the torque wrench.

[@andyvan5692]

good tips, BUT you can use the Torque wrench at this extension, mechanics do, they just find the torque reduction factor ( X 0.9 etc.) that the wrench maker has in the instructions with the wrench, then apply this factor to the target torque, eg: if you double the length you halve the torque, x 0.5 so if 500 ft/lb was called for you set 500 X 0.5 = 250 ft/lb on the wrench, this gets you where you need to be. this is used on gearbox adjusters, etc. where the room to swing the wrench is limited; only for emergencies, NOT for general practice, in normal bolting applications you use an appropriate sized Torque wrench for the job! ( there are special extension spanners for this purpose, their instructions also tell you what the correct setting for the wrench should be).

[@louisrosner7902]

Another great video. Loved the 90° tip

[@davidmullet1030]

Thank you

[@drewharteveld9874]

Another valuable episode, and GREAT companion to the DVD. Thanks.

[@RandyMabusedJW]

Great video. Most of us just tighten until it cracks then back off a turn. Lol

[@mostefatayebcherif6798]

Good morning everybody , thanks sir for this crucial information

[@theyear-pj4sj]

Excellent video

[@maniagokm3186]

Good one Jon. Thanks. "Now everyone, back to building!"

[@GregsZenithSTOLCH750]

Great information as always, Jon!

[@faainspector9699]

Should -06 fuel line nuts be lockwired to prevent loosening from vibration??????

[@spikekavalench]

Excellent advice, thanks!

[@MrAcacio]

Thank you so much for your great video.

[@thombarlow5977]

WOULD YOU TELL US WHAT SIZE ALUMINUM TUBING IS USED WITH WHAT SIZE AN FITTINGS PLEASE

[@sey1yes2]

Great information! Thanks!

[@blondprince9507]

Good morning sir , beautiful and useful

[@lisaleedavidson]

Sorry but the 90 degree method is not correct. The torque arm provided by the crows foot would be the same torque arm no matter the angle. This is because the length of the torque arm from the point of application (drive head 1/4, 3/8, 1/2) of the torque would be the same no matter. Your setting on the torque wrench is only accurate to the drive head center. This is why smaller torque wrenches can be used to tighten nuts or bolts beyond their range limit using a torque multiplier. This essentially adds a known torque arm extension to the drive head. The torque multiplier will then give you a multiplier for your setting on the torque wrench that provides the actual torque provided at the end of the extension (torque multiplier).

[@HomebuiltHELP]

Thank you Joel - you have me reconsidering the error of my ways.... I will look into the torque arm extension devices.

[@perrycorn2789]

I’m an aircraft maintenance engineer and I find a lot of engineers lame and Ame engineers over torque everything and one of my pet hates is people that over torque screws and use very long screws to put panels on and when we had hangar meetings I would bring this up all the time and would explain that if screw are to long they can hit control cables, wiring and other bits ant this was a problem with a Metroliner we’re the factory at build used a very long PK screw to hold a panel which went through a wiring loom and the aircraft would activate the auto feather on and off till one day the aircraft just rotated and the auto feather activated at full power feathering the prop just off the ground and the pilot was selecting gear up at the time and mealy lost the aircraft he landed safety and it took several days to find the problem. I surgery that if you are not sure read up on it and do not overtighten screws in an anchor nut as you stretch the anchor nut and it looses it grip on the screw and the screw will fall out just nip it and do not use long screws unless the dragon requires it 1 to 2 threads pass the end of the anchor nut is all required to hold the panel in place safely also if you over tighten it someone has to try and remove it or it will break and than that is how you end up with scratches in the paint work or holes in the skin if you don’t know what you are doing so as I say if you are not sure be a good builder and do the smart thing read up on it and ask someone that knows about these thing also over torquing my damage components and this can cause them to fail further down the line so if it calls for a torque even if it doesn’t fell tight enough the torque is there for a reason and if you are not sure ring the makers

[@poojabhavsar2944]

Can you tell me the product details

[@JOSEGONZALEZ-wx9fb]

Great video, very useful. keep it up.

[@samuelyoung9932]

Very detailed instructions ,better then some A & P instructor . Thank you for sharing .. Normally should I back it off and re torque it again?.🐒

[@n9308x]

I want to know about your tires. Can you tell us about the Turf Glide tires?

[@kimrickard7451]

What if you used an extension on the 90° rule?? Would it still be close enough?? By extension ,, I mean length,, like a dog bone, not a normal extension of the torque wrench.. Thanks

[@unimog875]

How about güt and tight?

[@NarraRick]

Maybe don't bend the aluminium tube by hand like in the video, I'd use a bending spring or a set of pipe benders over the tube.far less chance of kinks and The bends come out a lot neater. I'm a plumber, I bend pipes all day. I haven't built my plane yet I've purchased all of your videos on the CH 650 so I may be wrong, just my opinion, let me know. Great videos you guys put out.

[@christopherblakeley]

NarraRick yup, don't bend in your hands, too easy to flatten or kink soft tubing(as you certainly know). Also, do not tighten fittings with normal wrenches, most don't really fit the flats very well and do slip off. Flare nut wrenches are pretty inexpensive and generally double ended so you don't need many. And for the few times you will use them, flare crowfoot wrenches can be had from Harbor Freight for next to nothing. Always use acceptable practices. Don't shortcut because it's a "homebuilt". 20yrs AP/IA taught me there are no free shortcuts.

[@NarraRick]

Chris thanks , I've got my pluming flaring tool and use it a bit but different sizes for copper pipes { we normally only flare gas fittings} But the whole torque wrench bit and the crowfoot wrench was great, I had no idea about them.I love these video tips . So helpful.

[@christopherblakeley]

NarraRick remember that plumbing flaring tool is most likely a different angle than used in aviation! I believe plumbing flares are 45deg?? AN fittings use a 37deg flare. Now, build that plane!!

[@NarraRick]

Ah ! didn't know that, and yeah I don't think I'll be using my plumbing tools on the plane:} Saving up the money for the plane I'm hoping to purchase in the new year if all goes well.CheersRick

[@deans4x4]

Also, remember aircraft require double flared instead of single flared fittings.

[@savethedeveloper]

10:01 that is the wrong torque setting for 3003?

[@crawford323]

Why or what is the origination of the name crows foot

[@clydecessna737]

Very helpful!

[@schorn]

Clyde Cessna ;

[@christopherstewart3446]

Can you use 6061 tubing?

[@ronaldfranck6960]

The torque wrench depicted has a stamp or sticker that says it's calibrated and tested. Does Tekton do this or a third party? The inch pound torque wrenches from Tekton are 1/4 inch drive, crows feet generally are 3/8 inch drive. I assume a 1/4 - 3/8 adapter was used?

[@mattkelly2938]

tighten until it breaks then back off a quarter turn lol

[@jesusisalive3227]

You tighten until it's tight then stop.