A-frame Swing Set

I'm new to this site and couldn't find the appropriate forum to ask my question regarding a swing set I want to build for my kids, so please let me know if I need to post elsewhere, and where to go.

I want to build a swing set to hang a wood airplane swing that my father crafted for my son and a tire swing. Problem is, I live on the side of a mountain and my soil is so rocky that I can hardly dig more than 4-6 inches down, so embedding the posts that I'm going to use in the ground with concrete is out of the question.

I have a huge pine tree that's about 3 and a half feet in diameter (but no useable branches to hang swings from, though) and I was thinking about building one a-frame using the "Easy 1-2-3 A-Frame Swing Set Bracket" from Eastern Jungle Gym for one end of the swing set and securing the other end of the swing beam into the trunk of the pine tree.

Would that be stable enough to use without burying the legs of the A-frame into the ground with concrete? Do you know of alternative ways to secure the a-frame? Are there any foreseeable issues that may come up with this design?

I'm handy with tools but am a beginner in most areas, as you can probably tell

 

Even if that is true which I don't think that it is, you still should be able to sink something in the ground & bolt the posts to it. I have no idea what an Eastern Jungle Gym is. The pine tree should be a secondary support.

 

I certainly could try to sink something into the ground, but not anything as big as a 4x4 (size of the legs for the a-frame) without it taking weeks of shoveling to just get two holes big and deep enough.
What type of hardware can I buy to sink into the ground and bolt the 4x4s to? What is it called?

Thanks for your advice!

 

There are many different types of metal stakes available. Go to images.google.com
Search for metal stakes.

 

I also live in the mountains [mostly slate rock] and while holes are difficult to dig it can be done by hand. I often start out using a pickaxe.

 

You could try to use a hammer drill and install sleeve anchors to attach post blocks, similar to when you attach deck posts to concrete footings.

 

Something like this might work:

Shop 30-in Mobile Home Anchor at Lowes.com