Honeywell is introducing a high-efficiency mode upgrade for its 131-9B auxiliary power unit (APU) on Boeing 737NG and Max airplanes. The enhancement, which the company will make available in the second half of this year, employs a more efficient diffuser that regulates airflow to the APU, saving fuel and lowering emissions while increasing inspection intervals, Honeywell said.
With an estimated fuel consumption reduction of about a half-gallon per hour, Honeywell said the improved diffuser can reduce CO2 emissions and fuel costs by about 2 percent each. Meanwhile, time-on-wing increases to 1,500 APU running hours.
“Globally, airlines are working to reduce their carbon footprint, and every incremental step will help them achieve their net-zero carbon emissions targets,” said Honeywell president for Americas aftermarket Heath Patrick. “An airline with a fleet of 50 B737s could realize as much as $450,000 [€411,252] in annual fuel savings and reduce its CO2 emissions by up to 1,100 tonnes, depending on operating conditions. A major airline carrier recognized a fuel savings of 2.46 percent.”
Patrick also estimated that the higher time on wing can result in fewer service events costing $315,000 per visit.
According to Honeywell, the upgrade can be installed during any regularly scheduled maintenance event without needing any extra downtime. A similar upgrade for 131-9A APUs on Airbus A320-series aircraft introduced in 2020 is now installed on more than 700 airliners.