• The Biplane Forum is a large global active community of biplane builders, owners and pilots. From Pitts to Skybolts, to older barnstormers, all types are welcome. In addition to our active community, our content boasts exhaustive technical information which is often sought after for projects and maintenance. This information has accumulated over the 12+ years the forum has been in existence.

    The Biplane Forum is a private community. Subscriptions are only $49.99/year or $6.99/month to gain access to this great community and unmatched source of information not found anywhere else on the web. We are also a great resource for non biplane users, since many GA aircraft are built the same way (fabric and tube construction). Annual membership also comes with two BiplaneForum.com decals.

S1-11B Planning: Any Recommendations?

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.


Well-Known Member
Aug 20, 2017
Reaction score
Hey everyone - I don't post here much but have found it an infinitely valuable resource. So, thanks.

I'm doing some cost and feasibility research on a potentially ambitious project: building two S1-11Bs concurrently.

A friend and I have been chatting about this for awhile during our beer-fueled hangar talk. He currently flies a highly modified S1S and I fly a Christen Eagle (poorly). Initially it started as an idea to simply build an S1-11B, but then we thought perhaps building a second plane while we're at it would only make sense? Heck, maybe build a third and sell it one they're completed to offset some costs 🤷‍♂️

I'm a welder, certified for aerospace, with a shop full of fabrication equipment; both manual and CNC. My background is CAD, 3D modelling, prototyping, mould-making. I'm a shitty pilot, but I'm pretty good at designing and building things. My friend is an AME/A&P who's worked in the Red Bull Air Race for 20 years. He has a very unique set of skills, and a large orbit of support when it comes to building/engineering/maintaining/flying all types of acro and race planes. He's a good stick, too.

A couple years ago I bought a set of S1-11B plans from Aviat and since then I've been compiling notes, ideas, and questions on the build process. The goal is to build both planes identical. We aren't concerned with keeping them original, but don't want to get too far from the plans. Modern tweaks in design and materials are all on the table. The information that's here and other places online is somewhat limited since there hasn't been too many built, so I thought I'd just ask the community a couple of questions:
  • Since the original 1995 design, has there been any 'common' modifications that builders would tend to lean towards nowadays? And speaking of Wolf Wings... The leading edges in the plan are aluminum, so other than upgrading those to wood or CF, are there additional performance mods that could be incorporated into the wing design, or would anyone recommend that the wings in the plans be replaced entirely by a more contemporary design?
  • How about the tail section? I'm struck by how small the VS and rudder are, by modern metrics.
  • My experience is all 4cyl, so I'm not too familiar with the IO-540. Does anyone have recommendations on what models of 540 we should keep an eye out for while looking for a decent base for a rebuild?
Alright, these are the first round of sticky notes.

Thanks everyone.

Latest posts