What happens to fuel burn when diverting to another airport after lowering the gear by free fall?

When a Falcon 7X aircraft diverts to another airport and the landing gear is lowered by free fall, several aerodynamic and operational factors contribute to an increase in fuel burn. Lowering the gear creates significant drag due to the change in the aircraft’s aerodynamic profile; the extended gear disrupts the smooth airflow over the fuselage and increases resistance against the thrust generated by the engines.

As a result of this additional drag, the aircraft needs to increase its thrust output to maintain the desired airspeed and glide performance, leading to higher fuel consumption. The increase in fuel burn by approximately 80% is indicative of the significant impact that gear deployment has on overall aircraft drag and the resulting fuel efficiency during a diversion. Therefore, this scenario illustrates how mechanical and aerodynamic changes during flight can disproportionately affect fuel efficiency, particularly in situations that require immediate changes such as an unplanned diversion with gear extension.