Series Hybridisation: Turning the Dirtiest Flights into the Most Sustainable

Very short-haul flights—under 270 nautical miles—represent 25% of European aviation and carry a hidden environmental cost: they emit 155g of CO2 per passenger kilometer, nearly twice the industry average. The culprit is inefficient fuel burn during takeoff and landing phases. In a new opinion piece published in Aerospace Global News, Helix’s Chief Engineer Derek Jordanou-Bailey challenges conventional thinking and reveals why neither sustainable aviation fuels nor pure electrification can solve this problem—but series hybridisation can.

The energy density mismatch is fundamental: lithium-ion batteries deliver 200Wh/kg versus jet fuel’s 12,000Wh/kg, making pure electrification viable only for small turboprops with a 150 NM range. Series hybridisation sidesteps this barrier by using battery power for takeoff and landing—the fuel-intensive phases – while an onboard engine recharges batteries during cruise. The result is dramatic: a series hybrid turboprop could reduce very short-haul fuel burn by 75-90% compared to conventional aircraft, cutting emissions to just 15.5g CO2 per passenger kilometer—one-fifth the current average.

Beyond environmental gains, the transformation delivers economic and operational benefits. With fuel comprising 30% of airline operating costs, series hybridisation reshapes profitability while enabling smaller regional airports to handle traffic, reducing congestion and passenger travel time. One architectural change could simultaneously solve aviation’s most persistent sustainability challenge and make very short-haul routes the most cost-efficient and sustainable flight category in the industry.

Read the full article: Series Hybridisation: Turning the Dirtiest Flights into the Most Sustainable — Aerospace Global News