Page 1 of 2 12 LastLast
Results 1 to 40 of 42

Thread: Tie-Downs and Straps

  1. #1
    twl's Avatar
    Join Date
    Dec 2016
    Posts
    4
    Post Thanks / Like

    Tie-Downs and Straps

    Any suggestions on tie-down and strap choices would be greatly appreciated.
    I am attending my first camping fly in at Madden's resort in Minnesota and will be camping under the wing a bunch this summer. Not sure if the claw from Sporty's is a good idea or if I should buy something else for the times there aren't tie-downs available. Also some proper procedure on tying down the tail of my PA-12.

  2. #2
    Ken Kennedy's Avatar
    Join Date
    Dec 2008
    Location
    Lubbock , Tx
    Posts
    50
    Post Thanks / Like
    The Claw has worked great as an anchor point for me for years, but does not work the best in some sandier types of soil.

    As for the Lines themselves, I absolutely love the knotless tie downs I got from this guy https://backcountrypilot.org/forum/1...oto-dump-17878.




  3. #3
    Grant's Avatar
    Join Date
    Mar 2002
    Location
    Woodbury, MN
    Posts
    1,552
    Post Thanks / Like
    That line is called Spectra or dyneema. It's used in sailing and it's awesome. No stretch.

    http://www.novabraid.com/rope-materi...ra-fiber-rope/

    https://m.youtube.com/watch?v=d0B6tYTVHVM
    Last edited by Grant; 05-06-2017 at 06:01 PM.
    Likes Wag2+2, Chicken Hawk, skywagon8a liked this post

  4. #4
    twl's Avatar
    Join Date
    Dec 2016
    Posts
    4
    Post Thanks / Like
    Great stuff, I've ordered and received the clay and the lines. Anyone on input for tying down the tail should the winds necessitate?

    Sent from my XT1650 using SuperCub.Org mobile app

  5. #5

    Join Date
    Dec 2006
    Location
    Meanwhile,...
    Posts
    4,232
    Post Thanks / Like
    I've had good luck with the Claw for 10 years or so but for New Holstein's sandy/silt and storms I use augers and I don't mean doggie screws.

    Not sure about using being a good choice or not, depending upon your opinion of the effect of shock loads being transmitted uninterrupted to the anchors. Spectra it's good stuff (you get to step down usually two size) and works great for light air spinnaker and headsail sheets but in a blow I did some significant hardware damage with it back in my sailing the days. For tie downs I use low-stretch Gold Braid dock lines from West.

    I tie the tail a little bit loose so you get some movement but so that it won't raise high and risk a tip over.
    Last edited by OLDCROWE; 05-18-2017 at 06:41 AM.
    "Don't feed the hipsters"
    Likes white mountain liked this post

  6. #6

    Join Date
    Oct 2006
    Location
    Seldovia, Alaska
    Posts
    99
    Post Thanks / Like
    I would strongly recommend using line that does strech for tiring down an aircraft. It allows shock from a gust to be absorbed by the line instead of transferring all the shock to the aircraft structure. Use good quality (not cheap) nylon line, not nylon and mixed fibers also learn a few basic knots. A bowline is essential and while many people use a rolling hitch which supposedly locks on a line, they can slip. I tie my knots at the tie down so they can't slip. If the line is long, I may tie my bowline at the wing and half hitches at the ground so the long unused line is on the ground and won't beat on the plane in a strong wind.

    Cubs have had failures of the lift strut attach fittings that connect the lift struts to the spars. Both fatal and non fatal. Those who use chain, or even ratchet straps are asking for trouble. One such failure on the Alaska Penninsula in the late eighties or early nineties prompted ATLEE to make two STC's, an insert that went inside the lift strut attach fitting on a cub and a tie down that went arround the spar outboard of the lift strut attach fitting thereby not involving the strut attach fitting in the tie down. I have a seat belt strap arround the spar instead of the Dodge tie down on one of my Cubs. That strut attach fitting is made to take a load in tension but when used as a tiedown the load is no longer in the direction which it was designed for and in the direction where the strength is. There is a service bulliten concerning the inspection of the lift strut attach fitting.

    i do carry a realitively long piece of small diameter winch line. Sounds like it is similiar to this specter. I use this to tie to a tie down like a tree or something that is a distance away, and then tie my tiedown line to it. It is light, strong and has no strech and should only be used as a tie down line as a very last resort.
    Thanks C130jake thanked for this post
    Likes NunavutPA-12 liked this post

  7. #7

    Join Date
    Aug 2002
    Location
    Talkeetna Alaska
    Posts
    178
    Post Thanks / Like
    Remember the wings are designed to lift more than the gross weight of the aircraft. You may want to select the line strengths accordingly
    Likes C130jake liked this post

  8. #8
    Tim's Avatar
    Join Date
    Feb 2002
    Location
    Petersburgh, NY
    Posts
    3,330
    Post Thanks / Like
    Quote Originally Posted by reliableflyer View Post
    I would strongly recommend using line that does strech for tiring down an aircraft. It allows shock from a gust to be absorbed by the line instead of transferring all the shock to the aircraft structure. Use good quality (not cheap) nylon line, not nylon and mixed fibers also learn a few basic knots. A bowline is essential and while many people use a rolling hitch which supposedly locks on a line, they can slip. I tie my knots at the tie down so they can't slip. If the line is long, I may tie my bowline at the wing and half hitches at the ground so the long unused line is on the ground and won't beat on the plane in a strong wind.

    Cubs have had failures of the lift strut attach fittings that connect the lift struts to the spars. Both fatal and non fatal. Those who use chain, or even ratchet straps are asking for trouble. One such failure on the Alaska Penninsula in the late eighties or early nineties prompted ATLEE to make two STC's, an insert that went inside the lift strut attach fitting on a cub and a tie down that went arround the spar outboard of the lift strut attach fitting thereby not involving the strut attach fitting in the tie down. I have a seat belt strap arround the spar instead of the Dodge tie down on one of my Cubs. That strut attach fitting is made to take a load in tension but when used as a tiedown the load is no longer in the direction which it was designed for and in the direction where the strength is. There is a service bulliten concerning the inspection of the lift strut attach fitting.

    i do carry a realitively long piece of small diameter winch line. Sounds like it is similiar to this specter. I use this to tie to a tie down like a tree or something that is a distance away, and then tie my tiedown line to it. It is light, strong and has no strech and should only be used as a tie down line as a very last resort.
    How do you have time to post here, aren't you to busy looking after Glenn
    Likes Poor Joe liked this post

  9. #9

    Join Date
    Oct 2006
    Location
    Seldovia, Alaska
    Posts
    99
    Post Thanks / Like
    He just left this morning and while he was here he was explaining to me how this site worked He pulled this post up.

    It was a pleasure to have him here. I think he may want to come back.

  10. #10
    Tim's Avatar
    Join Date
    Feb 2002
    Location
    Petersburgh, NY
    Posts
    3,330
    Post Thanks / Like
    Quote Originally Posted by reliableflyer View Post
    He just left this morning and while he was here he was explaining to me how this site worked He pulled this post up.

    It was a pleasure to have him here. I think he may want to come back.
    He's been texting me pictures, beautiful place up there

  11. #11

    Join Date
    Oct 2006
    Location
    Seldovia, Alaska
    Posts
    99
    Post Thanks / Like
    It certainly is a beautiful place. He and Bev enjoyed it. We caught a 40 pound halibut, ate some fresh salmon, they went kayaking and he flew my cub for a bit. In a week moment he admitted that mine got off shorter than his. It was the festive week and lots going on. I think he wants to come back.
    Likes Farmboy, cubdriver2 liked this post

  12. #12

    Join Date
    Oct 2012
    Posts
    2,254
    Post Thanks / Like
    Stretch in tie down rope is a bad thing. Watch your plane bounce up and down as the rope stretches compared to sitting firmly in place with static rope. Sitting still is better.

  13. #13
    WindOnHisNose's Avatar
    Join Date
    Apr 2003
    Location
    Corcoran MN
    Posts
    3,661
    Post Thanks / Like
    I am concerned about the carabiners that some people use, as illustrated in your photo at the top of this thread. They need to be rated to a very high strength, and I am not sure any associated even with mountain climbing will be strong enough.

    Randy
    Thanks TJAK thanked for this post
    Likes mike mcs repair liked this post

  14. #14

    Join Date
    Oct 2006
    Location
    Seldovia, Alaska
    Posts
    99
    Post Thanks / Like
    Quote Originally Posted by stewartb View Post
    Stretch in tie down rope is a bad thing. Watch your plane bounce up and down as the rope stretches compared to sitting firmly in place with static rope. Sitting still is better.

    I need to take issue with your statement about strech vs no strech in tie down line. They build cars now that slowly crush during a collision to prevent sudden stops and absorb the shock over a longer period of time.

    . The risk comes when their are gusts which cause sudden jerks on the planes structure. What's more, in a tied down situation the force of the wing moving up in a gust is concentrated in one location on that structure. Many airports provide chain. In strong gusts as the wing is pulled or forced up, it jerks hard when it hits the end of the chain. I had my wife pull one of my ratty old cars with a chain once to get it started. I said get it up to twenty or so. She did right then and streched the bumper out two feet and bent the frame rails of my studebaker. The same happens with non stretchable rope. If stretchable rope is used the force is partially absorbed in stretching the rope and less force is imparted to the wing structure. As I recollect the boom vang on a sail boat is made to absorb some of the shock on the structure when the boat comes hard about? They used to use springs on the chain restraints on screen doors so that when we ran out and the door opened fast the spring would absorb some shock to prevent pulling the screw eye out.

    I should add for clarity, I do not leave slack in the tie down lines. They are snug not stretched and tied with appropriate knots usually a bow line at the ground tie down and half hitches right against the tie down ring. The stretchable rope like a high quality nylon line not mixed fibers acts as a spring when the gust starts to jerk the plane since the lines are snug the resistance is ther a little bit at a time throughout the total rise of the plane. Up you tiedown lines at a boat store, not Walmart. Buy lines that are ment to take shock.

    As I recollect it was in the early 70's in Anchorage, Judge Kalimeredies was killed when he lost the wing of a super cub. My recollection on that one is fuzzy. In the late 80's or early 90's a State of Alaska Wildlife super cub was tied down on the Sandy river on the south end of the Alaska Penninsula. Two of the guys I worked with stayed in their tent for three days while it blew. At the end of the blow the pilot, one of the bettter cub pilots I know and one of my mentors for about 40 years now inspected the plane. He removed the inspection cover aft of the spar at the wing attach fitting. Because he saw that the compression member had been pulled down against the fabric somewhat more than usual. It requires close examination. He found the lift strut attach fitting on the aft side of the front spar was slightly bowed but no kinks or cracks. Since the fitting portion forward of the spar is not visible since it is under the leading edge he took his knife and cut a hole in the fabric and leading edge aluminum. . He then examined the fitting forward of the spar and found a slight bow but no cracks or kinks. The took off and at about 100 feet the wing separated at that fitting. It folded up and the rear fitting failed. The wing went up still connected at the wing root, the asicraft rolled and they went into the Sandy river inverted. Fortunately the survived the wreck, drowning and the hypothermia that followed. That incident was was well observed and understood. ATLEE promptly designed a lift strut fitting support piece now sold by F A Dodge and by Univair. The distance between the strut bolt in the fitting at the tie down and the bolt that gots through the spar is anout 6 1/2 inches. It is made to take force in tension, a straight line along the total fitting into the strut and the the strut forks. When we tie to the tie down ring or the strut up by the wing and the wind gusts force the wing up and the wing tries to fly the tie don line places a strain on thatstrut attach fitting at an angle of perhaps 45 degrees from the angle that it is designed to take the load. Furthermore the force is the end of a 6 1/2 inch lever. Inspection of the is fitting is discussed in a service bulliten where their is a small hole cut in the leading edge and patched with a bullet hole patch after the inspection. I have even seen the welds on a factory tie down ring fail. I should also mention that ATLEE also made. Tie down STC for a cub which is a metal strap that goes around the spar outboard from the lift strut attach fitting and does not involve that fitting in the tie down. On one of my Cubs I have taken a seat belt strap and put it arround the spar so the tie down force is applied perpendicular to the spar outboard of the lift strut attach fitting.

    I suppose if a plane net is tied down where it is not subject to severe winds it probably doesn't matter. My experience and education has come from many years flying in Alaska and I have learned that line that will absorb some shock as the winds jerk a plane is easier on the aircraft than line which transmits all the shock to the airframe.
    Likes skywagon8a, super stol liked this post

  15. #15

    Join Date
    Oct 2012
    Posts
    2,254
    Post Thanks / Like
    I watched my 180 ride out 117mph winds in 2003 tied with static climbing ropes. The only motion it had was from tire squish and there wasn't much of that since I had it tied tight. I've watched the same plane dance and jump around on dynamic climbing ropes in less than half the wind. I was worried about it tucking the gear so I added static roles to calm it down. My choice is from experience as well. To each their own.
    Last edited by stewartb; 06-27-2017 at 03:28 PM.
    Likes FdxLou, apollo liked this post

  16. #16
    www.SkupTech.com mike mcs repair's Avatar
    Join Date
    Aug 2004
    Location
    chugiak AK
    Posts
    8,301
    Post Thanks / Like
    Quote Originally Posted by reliableflyer View Post
    ...If stretchable rope is used the force is partially absorbed in stretching the rope and less force is imparted to the wing structure. ....
    he's gonna be rich... sounds like over unity talk.....

  17. #17

    Join Date
    Jan 2007
    Posts
    970
    Post Thanks / Like
    So if you want no stretch would you use chains instead of ropes for your tie downs?? Just throwing fuel on the fire.
    DENNY
    Likes WanaBNACub liked this post

  18. #18
    sjohnson's Avatar
    Join Date
    May 2002
    Location
    Boise, ID
    Posts
    497
    Post Thanks / Like
    Quote Originally Posted by WindOnHisNose View Post
    I am concerned about the carabiners that some people use, as illustrated in your photo at the top of this thread. They need to be rated to a very high strength, and I am not sure any associated even with mountain climbing will be strong enough.

    Randy
    Good point. Carabiners should be the screw locking type, of high quality. I forget exactly, but mine are rated for 6000 pounds or so, which is about the tensile strength of typical climbing line, particularly after the line is looped through a ring. Carabiners only need to be stronger than the wing tie down rings. We once had a big blow in Boulder, CO, damaging a lot of planes. Some went airborne. Typically, it was the tie down rings that broke.
    "Beer is no longer another flavor of coffee, it prevents you from being stunned and gives you unlimited stamina for 60 seconds."

  19. #19

    Join Date
    Oct 2012
    Posts
    2,254
    Post Thanks / Like
    The problem with chains is slack. The plane moves a couple of inches and hits a dead stop when the slack is taken up. When I tie my plane there's no slack in the ropes and when the winds blow there's no movement. That's the point of tying it down. Dynamic ropes stretch about 25%. That means a 100" rope tied tight may be 125" long when stretched, so one side of my plane may be up to 25" off the ground in a hard gust? Not my airplane. Been there, done that, retired that rope. My current static rope is rated at about 5% stretch but I haven't seen light under the tires even in a strong wind.
    Last edited by stewartb; 06-28-2017 at 10:24 AM.
    Likes DENNY, 68Papa liked this post

  20. #20
    55-PA18A's Avatar
    Join Date
    Dec 2003
    Location
    Dillingham, Alaska
    Posts
    492
    Post Thanks / Like
    Differing opinions on using rope with or without stretch is a good discussion, but something we should all agree on is don't expect cheap rope to work. Some of the line I've seen used to tie down aircraft was down right scary, especially if in the vicinity of my plane. Take some time to look at the static load and strength of line before you buy it, and think about what your going to be tying down.

    I also think there's a lot to be said about spoiler covers if you're wanting to keep your plane on the ground.

    Jim
    Thanks wagondriver thanked for this post
    Likes 68Papa liked this post

  21. #21

    Join Date
    Oct 2012
    Posts
    2,254
    Post Thanks / Like
    Yep, spoilers work good, but when the winds are greater than 45-50 my covers come off.

    Anyone have any good pireps for vented spoiler covers? I leave town for weeks at a time in winter and still use a trick 55-PA18 taught me. I use my solid covers and then add my mesh spoiler covers over those. It's a bit of a pain for everyday use but for weeks way it's worked great. Covers that behave and perfectly clean wings. My new Cub will see the same treatment but I would like some vented covers for everyday use. I expect to employ another idea that AKPA18 offered years back. Add an earth anchor under the cabane to allow the plane to be tied down and still be able to rotate it nose to the wind. Good idea!
    Last edited by stewartb; 06-28-2017 at 11:18 AM.

  22. #22
    spinner2's Avatar
    Join Date
    Dec 2006
    Location
    Montana
    Posts
    1,519
    Post Thanks / Like
    Quote Originally Posted by stewartb View Post
    Add an earth anchor under the cabane to allow the plane to be tied down and still be able to rotate it nose to the wind. Good idea!
    IMG_0072.jpg

    I got caught in a big blow a couple of years ago and used my tail tie-down under the cabane. The wings were tied down and tail was free to move some.

    It blew harder later and I was sitting in the front seat dosing off. I woke up when the left wing anchor broke loose and the right wing touched the gravel. Instinctive left stick saved the day (night actually) along with a lull in the wind.
    Nicht der Ort fur mich.
    Likes stewartb, mike mcs repair, FdxLou liked this post

  23. #23

    Join Date
    May 2011
    Location
    Albuquerque, NM
    Posts
    72
    Post Thanks / Like
    Quote Originally Posted by twl View Post
    Any suggestions on tie-down and strap choices would be greatly appreciated.
    I am attending my first camping fly in at Madden's resort in Minnesota and will be camping under the wing a bunch this summer. Not sure if the claw from Sporty's is a good idea or if I should buy something else for the times there aren't tie-downs available. Also some proper procedure on tying down the tail of my PA-12.
    I'e had good success with the Claw in all types of soil, including New Holstein although I don't recall any high winds there.

  24. #24
    www.SkupTech.com mike mcs repair's Avatar
    Join Date
    Aug 2004
    Location
    chugiak AK
    Posts
    8,301
    Post Thanks / Like
    I like to add snaps to attach wing covers(spoiler type) to bottom of leading edge. Keeps them from rotating back in wind storm and becoming useless.

  25. #25
    PerryB's Avatar
    Join Date
    Aug 2007
    Location
    Northern Calif.
    Posts
    1,200
    Post Thanks / Like
    With regard to stretch vs. no stretch (assuming a solid anchor), I'm in Stewart's camp on this one. I use ratchet straps and draw them down slightly snug. No slack equals no jerk/shock.
    After Monday and Tuesday, even the calendar says WTF !

  26. #26
    www.SkupTech.com mike mcs repair's Avatar
    Join Date
    Aug 2004
    Location
    chugiak AK
    Posts
    8,301
    Post Thanks / Like
    psssst... as far as stretch goes...

    theres only so much stretch till no more stretch, and then you are just same solid....

    until it breaks in an extreme...

  27. #27
    windy's Avatar
    Join Date
    Dec 2005
    Location
    Utah
    Posts
    536
    Post Thanks / Like
    No matter how tight I tie down my Cub, I've seen it jump around in big winds due to the flex of the 31" Bushwheels. The tires trump the stretch or no stretch of the ropes/straps. Maybe the rope stretchiness would make more of a difference on planes with little tires.

  28. #28
    PerryB's Avatar
    Join Date
    Aug 2007
    Location
    Northern Calif.
    Posts
    1,200
    Post Thanks / Like
    Same here, but at least there is no jerk or jolt. Are you coming out to Kirk's fly-in at Booneville in Aug?
    After Monday and Tuesday, even the calendar says WTF !

  29. #29
    windy's Avatar
    Join Date
    Dec 2005
    Location
    Utah
    Posts
    536
    Post Thanks / Like
    Quote Originally Posted by PerryB View Post
    Are you coming out to Kirk's fly-in at Booneville in Aug?
    planning to. And you? See you there!

  30. #30
    Rob's Avatar
    Join Date
    Nov 2002
    Location
    AZ06
    Posts
    642
    Post Thanks / Like
    I am also in the camp tie it tight, and use rope that doesn't stretch,when I use rope. I say when, because even though I am quite handy with knots and lines, after trying a set of tie downs like the ones in the second post, it's almost all I use to tie down my planes. It's worth mentioning that there aren't many good ways to 'tie' amsteel, or any of the 'super lines'.

    Three of my airplanes survived a microburst that made a pretzel out of my neighbors cub, and blew a section of my wheel line a mile away. I get them down tight enough that even on big wheels, they don't move. The big tires provide cushion down, I don't see why anyone couldn't get a plane to quit moving up regardless of tire selection.

    As to use of carabiners, it is wise to select wisely. Having said that, the ones in the second post show a rating of 20KN on the spine or something on the order of 4500 pounds. I use a bit beefier ones, but I suspect that the tiny bolt that holds the tie down ring (mounted in shear) would fail before holding 4500#s, and have no doubt that any rope would be cut in two at the tie down at that pressure (I wrap the strut on a Cessna for that reason and others). Like most, I was suspicious of those wonder lines prior to putting them to the test. I'm sure I warmed up to them about like an old timer to a GPS. New technology always seems to get its fair share of skepticism. Now I flat love them. The speed at which they can be deployed is astonishing, and has come in handy a couple times already when the wind was stiff enough to execute an almost vertical landing into the tie down.

    Take care, Rob
    Likes hooligan liked this post

  31. #31
    Gordon Misch's Avatar
    Join Date
    Dec 2003
    Location
    Toledo, Wa (KTDO)
    Posts
    2,571
    Post Thanks / Like
    Are you coming out to Kirk's fly-in at Booneville in Aug?
    Perry, is this a public event? If so, would you have some more info?
    Gordon

    N4328M KTDO
    My SPOT: tinyurl.com/N4328M (case sensitive)

  32. #32
    Barnstormer's Avatar
    Join Date
    Sep 2013
    Location
    Sterling, Alaska
    Posts
    492
    Post Thanks / Like
    I'm also in the tie-down tight camp and use Hammer's Amsteel tie down system.

    For tie down anchors I carry duckbills and Abe's Tie Down System

  33. #33
    BC12D-4-85's Avatar
    Join Date
    Feb 2016
    Location
    Fairbanks, AK.
    Posts
    324
    Post Thanks / Like
    Ratchet straps if used as tie downs should be twisted between plane and anchor. If not and left flat will be worn out by the wind as the high velocity air oscillates and eventually wears out the fibers. Flat bad...round better.

    Gary
    Thanks PerryB thanked for this post

  34. #34
    PerryB's Avatar
    Join Date
    Aug 2007
    Location
    Northern Calif.
    Posts
    1,200
    Post Thanks / Like
    Quote Originally Posted by Gordon Misch View Post
    Perry, is this a public event? If so, would you have some more info?
    Yes, I believe anybody is welcome, even you . I'll get back on here in a bit with the info. I have to jump over to my email and pull it up. I stumbled onto the event by chance a couple years ago and it turned out to be a fun time. A lot of people come on the Fri and camp out for the weekend.

    ** I forwarded you a copy of the announcement. I hope you can make it, I'd enjoy seeing you again.
    Last edited by PerryB; 06-29-2017 at 05:01 AM.
    After Monday and Tuesday, even the calendar says WTF !

  35. #35

    Join Date
    Oct 2006
    Location
    Seldovia, Alaska
    Posts
    99
    Post Thanks / Like
    Preference is a good thing. We like certain colors for whatever reason so we paint our planes those colors. Using rope which can stretch vs rope which has no stretch is really just a physics or engineering issue.


    All tie downs should be tight, without looseness in the line. If one uses stretchable rope like nylon, it is like preloading a spring, tension is there and if it stretches the tension increases so it remains tight. We need to use line that exceeds the working and breaking force that can be imposed by our planes. West Marine says that nylon, which is normally considered the best for dock lines will stretch 16 percent when loaded to 15 percent of its breaking strength. USBoat has a good discussion of the value of shock absorption of lines which stretch. I know that planes are not boats but the physics and principals are the same.


    Most times the tie downs in the ground or the rocks, trees or logs that we are tying to, are not in the perfect locations for our planes. When in the field they are at times quite a distance from the plane. Frequently lines are angled out or back toward the plane from from the tie downs. Rarely if ever is the tail tie down in the perfect location. There is virtually always movement of the tail from one side to the other, sometimes the plane sideways of forward or backward, even if the lines are tight. Gusts or change in wind direction move the plane even if the tail wheel is directly over the tie down. There will be tail wheel movement from pivoting or twisting even if it is tied tight. Furthermore there is movement of the plane due to tire flex. If there is any movement of the tail, some slack in the tie down lines result, leaving the possibility of jerk if there is no stretch to the line. Line which can stretch can be preloaded which leaves room for more stretch and absorbs any loosening and also absorbs slack.


    The elevators should be tied down so wind can lift the tail slightly and reduce the angle of attack and relieves stress on the wings and tie downs. It also protects the tail when a gust hit it from behind.


    Trying to over power the wind with lines is like trying to over power ocean swells with lines. Movement allows pressure to be relieved and trying to stop all movement is futile. A good place to find good tie down lines is at a good marine supply store. There is a place for line which does not stretch. Sheets used for hoisting sails use line with no stretch but dock lines that need to absorb shock use lines that do stretch and none that I know of stretch 25 percent. Stretchable lines are not bunji chords.


    There are also differences in structure of a Cessna and a cub. The cub happens to have an issue with the tie down brackets which I mentioned in a previous post and requires special attention.


    We all should march to our own drummers and I have learned to listen to my knowledge and experience. I consider carefully advise being given to me.


    Perhaps one might choose to present this issue to an engineer. I have.
    Thanks cubdriver2, WindOnHisNose thanked for this post

  36. #36
    hotrod180's Avatar
    Join Date
    May 2008
    Location
    Port Townsend, WA
    Posts
    1,352
    Post Thanks / Like
    Quote Originally Posted by windy View Post
    No matter how tight I tie down my Cub, I've seen it jump around in big winds due to the flex of the 31" Bushwheels. The tires trump the stretch or no stretch of the ropes/straps. Maybe the rope stretchiness would make more of a difference on planes with little tires.
    How about lowering tire pressure, then tie down, then pump tires back up?
    Takes at least some of the "squish" out of the equation.
    This might help if you were forced to use chain tie-downs.

    FWIW I'm kinda surprised by the number of people I see that don't bother to even carry chocks, let alone tie-down lines.
    Cessna Skywagon-- accept no substitute!

  37. #37
    WanaBNACub's Avatar
    Join Date
    Aug 2012
    Location
    Eagle River, Alaska
    Posts
    425
    Post Thanks / Like
    I am also in the low stretch, tight tie down group. I had a bear hunting trip turn south my first year flying when the winds came up just after I went to sleep. Luckily I was camped right next to the plane and I had to be up all night long until the winds started to die down to keep tightening the somewhat stretchy ropes I had. The plane dance around like crazy no matter how tight I tied them. Now I use the same type of spectra line tiedowns as above. along with a second solid line if I expect the winds to come up. And if I can tie down to more than one anchor per wing I do that too. Another thing I do if I know its going to be windy is to dig holes to bury the mains and try to get the wings at as low an angle of attack as possible.
    Likes CamTom12 liked this post

  38. #38

    Join Date
    Dec 2004
    Location
    Nikiski, AK
    Posts
    55
    Post Thanks / Like
    I never rely solely on the tie down rings as I always take the rope thru it then around the strut then back thru the ring. Would hate to lose a bird with the failure of that little ring.

    Also prefer lines with a little give to them for shock absorption, even though they are tied tightly.

  39. #39
    cubdriver2's Avatar
    Join Date
    Apr 2003
    Location
    upstate NY
    Posts
    7,786
    Post Thanks / Like
    Quote Originally Posted by 68D View Post
    I never rely solely on the tie down rings as I always take the rope thru it then around the strut then back thru the ring. Would hate to lose a bird with the failure of that little ring.

    Also prefer lines with a little give to them for shock absorption, even though they are tied tightly.
    From what I understand the little ring is not what fails, it's quite strong, strong enough that it will stay put and the force pulling at a 45 degree angle will tear the spar where the attach bolts go thru it.

    Glenn
    "Optimism is going after Moby Dick in a rowboat and taking the tartar sauce with you!"

  40. #40

    Join Date
    Dec 2004
    Location
    Nikiski, AK
    Posts
    55
    Post Thanks / Like
    Was thinking more about Cessna's and should have put that little n there

Similar Threads

  1. J3 cub fuel tank straps?
    By aerialimage in forum Cafe Supercub
    Replies: 4
    Last Post: 09-28-2013, 05:40 AM
  2. PA-12 Tank Straps
    By KJC in forum Cafe Supercub
    Replies: 0
    Last Post: 03-24-2008, 03:00 PM

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •