Boeing 787's EDAS Saves Fuel with Tiny Holes and Electric Motors

The Boeing 787's hybrid laminar flow control system is called EDAS (Empennage Door Actuation System), and it's a key feature of the Dreamliner. However, only some variants of the aircraft - the 787-9 and 787-10 - have this system installed.

EDAS works by managing airflow across the leading edges of the tail surfaces to reduce drag and save fuel. The system uses millions of tiny perforations on the leading edges to create a smooth flow of air, which is maintained through a network of internal ducting and door assemblies driven by electric motors.

The sequence starts on takeoff, when the doors open in purge mode to clear away any moisture or debris that might have collected inside. Once the aircraft accelerates past 190 knots, the doors close and switch into suction mode, where airflow creates a vacuum inside the ducting, drawing outside air in through the microscopic holes.

Boeing estimates that EDAS saves around 25,000 gallons of fuel per year per aircraft, but some operators have reported that the real-world savings did not always match expectations once the added complexity and upkeep were factored in. As a result, some airlines have deactivated the system on portions of their fleets over time.