Spectrum Aeronautical (Booth No. 1947) has quantified the CO2 that will be generated by its Freedom S-40 and Independence S-33 business jets and compared those to competing jets to see how the Spectrum jets stack up emissions-wise. On a 600-nm flight, the midsize S-40 generates slightly less than 1,500 kilograms of CO2, according to Spectrum, while comparable jets should generate more than 2,000 kilograms to nearly 4,000 kilograms. The Williams FJ33-4A-powered S-33 light jet puts out about 1,100 kilograms and the nearest competitor in emissions totals should generate a little more than 1,400 kilograms. The most inefficient jet in that class reaches about 2,100 kilograms of CO2, according to Spectrum.

“By having a very light airplane to begin with, it requires less thrust,” said Spectrum vice president Mark Jones. The Spectrum jets are all-composite and built using a technique that makes them 40 percent lighter than competing aluminum jets, according to Spectrum.

Contributing to the Freedom S-40’s efficiency is the GE Honda HF120 turbofan, which features a fuel-sipping, combustor design, according to GE Honda Aero Engines executive vice president Atsukuni Waragai. The design includes a rich-lean combustion system, which allows for a lower fuel combustion temperature and thus lower nitrous oxide emissions. Hydrocarbon and carbon monoxide emissions are lowered by reducing the cooling air requirements for the combustor. An advantage of the HF120’s improved efficiency, Waragai said, is that it makes the engine more durable. “If the engine is efficient, you don’t have to raise the temperature so high.” In the 50-50 partnership between Honda and General Electric, both companies have contributed significantly to the HF120’s design. “We learn from each other,” he said. “They’re very good at making engines durable and reliable.”

“Many clients of ours are very environmentally conscious,” said Stefano Sturlese, CEO of Spectrum’s European office in Luxembourg. “We are already in our DNA green,” he said.