Chevrons: Boeing's Quieter But Thirstier Engine Solution

Boeing's engineers faced a classic trade-off when designing its latest aircraft families: the 787 Dreamliner, 747-8, and 737 MAX. They wanted to reduce noise around airports, but this came with an unintended aerodynamic penalty that increased fuel consumption throughout every flight.

The solution was 'chevrons,' serrated nozzles on the engine nacelles that create controlled vortices to mix exhaust flows more gradually. This reduces turbulence and jet noise during takeoff and landing, meeting airport noise regulations and calming public concerns.

However, this design compromise comes at a cost: a 0.5% reduction in available engine thrust, which translates into millions of dollars in additional fuel costs for airlines each year.