It uses two engines mounted on pylons above the wing, a configuration called Over-The-Wing Engine Mount, or OTWEM, by Honda Aircraft.[66] This configuration maximizes cabin space by removing the structure required to mount engines on the rear of the fuselage.[2] A similar over-wing engine configuration was used in the 1970s on the VFW-Fokker 614, but had limited the aircraft's speed due to interference between the engine and the wing.[3][68] This, along with the overall commercial failure of the VFW-Fokker 614, made the over-wing configuration unpopular with aircraft designers.[68][69][70] To avoid these issues, the HondaJet's designer used computer analysis and wind tunnel testing to find the optimal position for engine placement on top of the wings, which was determined to be at 75 percent of the wing chord.[67] The HondaJet's engines are positioned in such a way that the airflow over the wing is superimposed with the airflow around the engine to minimize wave drag at high speed.[71] The HondaJet designer calls this “favorable interference.”[69] This configuration not only eliminated the problems associated with earlier over-wing engine mounts, but actually reduced wave drag compared to a conventional rear-fuselage mounted configuration.[69] OTWEM configuration is often named the most unusual feature of the HondaJet.[8]