Here is one way to have a secure tail tie that can be released once the engine is started and the pilot is inside the aircraft. The entire rig will release with a tug by the pilot and can be retrieved through the aircraft door or window. Obviously, this is for airplanes without a starter that have to be hand propped.



Essentially the yellow loop anchors the tail wheel to the ground anchor. The tent stake acts as a release pin, and the grey line runs up to the cockpit where it both pulls the pin to unfasten the yellow loop, and retrieves the rig.

This is the basis of the unit...real, real simple.


Connection to the airplane is made by simply having the loop run around the tail spring above the tire, or through a ring attached to the tail spring like the Cessna Birddog sports. It’ll work either way, though if it’s just looped over the tire care must be taken to ensure the airplane doesn’t roll backwards and free the tire from the loop. Note that rigged properly the pin will not touch either the ground anchor or the tail spring.

Here's the release pin attached to the grey pull cord. In this example the airplane would be to the right.


Any suitable cordage will work. This example is made out of dyneema line which is ridiculously strong. The yellow cord is rated to 900 pounds, the grey line to 500 pounds. I don’t know what the yellow loop would break at with the aluminum tent stake acting as a pin, but I’d bet it's more than any aircraft spec’d without a starter motor can produce at full throttle. Of course larger line could also be used.

Dyneema line is also very slippery, making it a good candidate for sliding around tail springs and ground anchors. The rig releases easily under as much stress as I can generate by hand, but I haven’t tried it on a airplane yet. The only thing I can see being a potential issue is how the cord interacts with the tail spring.

The 1940 J3 Cub I got my tail wheel endorsement in had instructions in the operators manual how to run a rope tied to a ground anchor through the hand hold handle at the rear of the fuselage then up to the wing strut and tied there with a slip knot where the pilot could reach it from the seat. I think you had to leave the rope when you flew away though. You better patent your idea before someone steals it!

My wife has a 1940 Aeronca Defender that has a tow hook installed (not approved/legal) that was installed for this purpose. Just pull the tow hook release and away you go. Was told by an FAA rep that a placard at the tow hook and and at the release handle with "not for towing-tie down only" would be "helpful" if inspected. I figure my insurance company would blame the tail hook and try to not pay on a groundless claim if I ever filed a claim but at this point we judged it safer to prop by yourself and avoid the runaway scenario.

Hammer,

Test for problems before you patent. Murphy and I were so close that every time I tried to do something fancy, I got into that "Who knew" problem. Probably just me. I tied the tail down, propped, reset the throttle to closed, untied, and crawled in.

Contact

I too installed a glider hook release on a plane I had without a starter. Safe, worked great. Also flew a 200hp fuel-injected Pitts without a starter for years, including back and forth across the country. Always tied the tail to something to start, put a pebble in front of the tires, once started, carefully set to low idle, carefully untie rope, carefully climb inside careful not to bump throttle. Contemplated something similar to this, but rope was cheap and there was always a piece laying around somewhere, same with pebbles.

Whatever you do is always a good idea as long as it works, and a bad idea the one time it doesn't.

Not trying to patent anything here. Some folks were interested in a take-away tie down for hand propping and this is what I came up with. I recently spent a chunk of change completely replacing my starter system from the motor to the switch plus a new battery, so I've probably taken it as far as I'm going to.

Anyone who wants to duplicate it or use it for the basis of their own system please feel free!

That is freakin ingenious I am off to the strip to investigate.

A much simpler idea: Install a mixture control in that no electric airplane. To start, mixture full rich, prime with manual primer, mixture to idle cutoff. Place cheap Wal Mart plastic wheel chock (RV supply) in front of one tire. Prop the engine, and when it fires, reach around and push mixture to rich. Pull wheel chock with attached parachute cord, and off you go.

Of course, this doesn't work as well on all airplanes, but on the Cub, it works fine.

MTV

Hammer - that is a tidy solution. I'm thinking of shamelessly copying it, though I know very little about splicing braided cord. (Somehow I managed to earn my Eagle Scout in spite of an embarrassing deficit in knot and rope skills.) Can you suggest some tools and instructional resources to get started on this project?

A simple 3 ring release with cordage instead of metal rings works well too. Or Soy's cords tied to his chocks. He made it look easy.

mtv wrote:A much simpler idea: Install a mixture control in that no electric airplane. To start, mixture full rich, prime with manual primer, mixture to idle cutoff. Place cheap Wal Mart plastic wheel chock (RV supply) in front of one tire. Prop the engine, and when it fires, reach around and push mixture to rich. Pull wheel chock with attached parachute cord, and off you go.

Of course, this doesn't work as well on all airplanes, but on the Cub, it works fine.

MTV

So installing a mixture control is "much simpler" than splicing two pieces of cord?

Felix wrote:Hammer - that is a tidy solution. I'm thinking of shamelessly copying it, though I know very little about splicing braided cord. (Somehow I managed to earn my Eagle Scout in spite of an embarrassing deficit in knot and rope skills.) Can you suggest some tools and instructional resources to get started on this project?

Felix, the cordage you intend to splice is going to determine what technique and tools will work best. Many cordage manufactures have splicing instructions for their products. For Amsteel I use a variety of improvised tools... knitting needles, bent over pieces of wire, sewing "nit-pickers", latch hoods, large sewing needles...I don't use splicing fids because of the small diameter line I work with.

Pay special attention to the tapering of the ends prior to splicing...it's probably the single biggest factor in whether the splice comes together properly, and the most tedious and time consuming part of the process. If you're working with dnyeema cord you'll need a very, very sharp knife to cut the fibers...scissors simply won't work.

Splicing is fun if you're into that sort of thing. If you're not it's money well spent to just order custom splices from sailing or arborist supply houses.

Hammer wrote:

mtv wrote:A much simpler idea: Install a mixture control in that no electric airplane. To start, mixture full rich, prime with manual primer, mixture to idle cutoff. Place cheap Wal Mart plastic wheel chock (RV supply) in front of one tire. Prop the engine, and when it fires, reach around and push mixture to rich. Pull wheel chock with attached parachute cord, and off you go.

Of course, this doesn't work as well on all airplanes, but on the Cub, it works fine.

MTV

So installing a mixture control is "much simpler" than splicing two pieces of cord?

Well, it does if you consider a couple things:

1). A mixture control serves other important purposes.

2). In my experience, there is often (seems like nearly always) nothing handy to tie the tail to when starting. My hangar, for instance, is surrounded by asphalt ramp. And putting an eyebolt in my door would put the plane on a downhill.....etc.

Simple is good, and a mixture control is better at high DA.

MTV

Cool idea. I'd have that wrapped up into macramé in about 30 seconds.

Hammer wrote:Here is one way to have a secure tail tie that can be released once the engine is started and the pilot is inside the aircraft. The entire rig will release with a tug by the pilot and can be retrieved through the aircraft door or window. Obviously, this is for airplanes without a starter that have to be hand propped.



Essentially the yellow loop anchors the tail wheel to the ground anchor. The tent stake acts as a release pin, and the grey line runs up to the cockpit where it both pulls the pin to unfasten the yellow loop, and retrieves the rig.

This is the basis of the unit...real, real simple.


Connection to the airplane is made by simply having the loop run around the tail spring above the tire, or through a ring attached to the tail spring like the Cessna Birddog sports. It’ll work either way, though if it’s just looped over the tire care must be taken to ensure the airplane doesn’t roll backwards and free the tire from the loop. Note that rigged properly the pin will not touch either the ground anchor or the tail spring.

Here's the release pin attached to the grey pull cord. In this example the airplane would be to the right.


Any suitable cordage will work. This example is made out of dyneema line which is ridiculously strong. The yellow cord is rated to 900 pounds, the grey line to 500 pounds. I don’t know what the yellow loop would break at with the aluminum tent stake acting as a pin, but I’d bet it's more than any aircraft spec’d without a starter motor can produce at full throttle. Of course larger line could also be used.

Dyneema line is also very slippery, making it a good candidate for sliding around tail springs and ground anchors. The rig releases easily under as much stress as I can generate by hand, but I haven’t tried it on a airplane yet. The only thing I can see being a potential issue is how the cord interacts with the tail spring.

SOOO much better than my idea! The only thing I'd likely change on yours would be to close the hook on the pin--it would be annoying as all heck to yank the cord to pull the pin and find that the cord had loosened enough that the pin flopped out during the yank.

Cary

I like the mixture idea. That is for a Marvel carburetor. However a Stromberg NAS3 sereis carburetor, even if it has an operable mixture control, does not have "idle cutoff". Most J3 Cubs, Champs, Luscombes, Chiefs, Taylorcrafts, C120/140 and the like use Strombergs. I have 3 different airplanes with Strombergs and they will run peachy in the full lean position at start no matter the season. Changing to a Marvel is not a cheap option.

Jim

A truckers hitch (based on a slipknot) with a bight fed back through would work in place of the tent stake.

Lots of youtube videos online about splicing tools and techniques with amsteel or dyneema.

Installing mixture control in a Stromberg carb is not really a valid solution - unless you want mixture for other reasons. After owning a stromberg and flying it all over the high mountains of colorado - I wouldn't do it for hand starts.

I used chocks attached to cord and pulled them in from the cockpit once I was started.

mtv wrote:.......To start, mixture full rich, prime with manual primer, mixture to idle cutoff. Place cheap Wal Mart plastic wheel chock (RV supply) in front of one tire. Prop the engine, and when it fires, reach around and push mixture to rich. ....

I've brain-farted and started my airplane with the mixture out. Doesn't run for more than a few beats. You'd have to be pretty quick to push the mixture back in without the engine dying. Might work well for a Cub, standing behind the prop, but with a regular door and/or propping from in front, maybe not so much. IMHO.

can you send me the pictures of the rigging for tying the tail down and releasing from inside the airplane. Trying to download pictures but the system won't download it. thank you

I guess I'm not special enough to see the pictures either.

The pictures aren't showing up for me, anyone else?