The kit consists of Inconel exhaust pipes connected to a merge collector manifold – called the “4-in-1” collector – that feeds into an extender pipe on which the silencer is installed.
Primary exhaust pipes of the same length are designed to remove static pressure and increase engine power while reducing vibration.
The system’s “4-in-1” collector increases engine torque by mixing the exhaust gas flow, which also contributes to the higher power levels, company officials explained. The gas flow provides carburetor and cabin heating as well.
Atelier Chabord’s silencer has a perforated sheet metal expansion chamber with soundproofing material. It is installed on flexible mountings that contribute to vibration dampening.
The silencer originally was developed to meet a request from France’s National School of Civil Aviation (ENAC) for its fleet of 20 TB 10 Tobago aircraft, with the requirement to reduce noise levels without loss of performance. The goal was achieved and exceeded – as the kit’s installation results in a slight increase in power.
After two years of operation – during which nearly 3,000 flight hours have been performed, including the training of air traffic controllers – the concept was validated, company officials said. This led to the exhaust silencer kit’s launch.
The kit has received its Supplemental Type Certificate (STC) from the European Aviation Safety Agency (EASA) airworthiness authority for TB 10 Tobago models equipped with the Lycoming O-360-A1AD engine, making it applicable to nearly 700 aircraft in service.