Well Last week I was on a website called the biplane forum. I posted a topic about a very serious real world problem. I own a pitts S1S aircraft. This aircraft is an experimental aircraft. Not certified. Pitts are very popular airplanes in the aerobatic world. There are many different models that take many different engines that range in hp. The S1S can take from 100hp to 260hp. My aircraft has a modified Lycoming IO360 that puts out 260hp. The airframe is supposed to basically withstand 2500hrs of aerobatic flight with some minor repairs through its life. Because of the popularity of this aircraft there are many companies that make many aftermarket parts for them. I happen to own a set of aftermarket wings from a company called SPARCRAFT. This company came out in the 1970's. Back then the ribs where flat routed plywood ribs. These wings had a tendency to come apart. Needless to say the company went out of buisness. Recently the company reopened under a new owner. They changed the plwood ribs with built up truss style compression ribs. Now they say they are better than the factory designed wings. When an aircraft is new and experimental it has to fly for 25hrs to complete is test flying and receive an airworthiness certificate. My aircraft flew aerobatics from 25hrs to 70 hrstt. Now my wings are unairworthy. A pitts is a biplane. The upper wing has a fuel tank mounted in the center between two spars that ron the length of the wing. It has compresion ribs throughout. The wings have a total of 4 ailerons. There are 2 I struts that connect the upper wings to the lower wings. The lower wings also have two spars and compression ribs. The lower wings mount to the sides of the fueselage. The upper wing also has a center cabane support in front of the cockpit attached to the center of the upper wing. There are also 4 brunson or flying wire braces that run like an x pattern (if standing in front of the aircraft looking at the wings)for more cross bracing. The wings are covered in ceconite fabric. The first problem I had was the fabric on the top side of the wing kept tearing next to the fuel tank on both sides. Then the rib lacing (thread that penetrates the top and bottom layer of the fabric wrapped around each rib in 4" intervals) began tearing. The final straw that made them unairworthy is there is a vaccumed formed plywood leading edge. On top of every rib the leading edge cracked through and through. I am a pretty knowledgeable aircraft mechanic so I noticed the damage occuring. But to the regular pilot the odds of a person getting in serious trouble are great. 100's of these wings have been sold to the general public. I haved reported them to the faa. I tried to make this information known on the biplane forum. Most of the pitts builders converse there. The owner of the sparcraft company threw a fit and they erased my post and banned me from that site in under a day and a half. I would like to know if there is an aeronautical structural engineer who could calculate how much g-force those wings can handle if I gave them tall the hard numbers. Airfoil dimensions gross weight prop diameter pitch rpm wing loading wing area. There are also 3-d drawings available to the public on www.steenaerolab.com That is who owns the rights to the original pitts S1S design. Please write back and I will add all the information I can muster up.