Abstract: At 7:00 p.m. on May 11, 1992, a contractor was erecting a scaffold in a 90 ft high combustion chamber at a co-generation plant owned and operated by Air Products. Poles were being passed through an 18 in. diameter opening in a crossover between the combustion chamber and the south cyclone by an employee who was tied off. Without the employer's knowledge, Employee #1, a carpenter for Brand Scaffold Services, Inc., went to the north cyclone's crossover, looked out a similar opening, stood up, and fell backward into the cyclone. He fell approximately 50 feet down the cyclone. Employee #1 sustained a broken right ankle and burns to the buttocks from the residual hot ash at the bottom. A general citation was issued.