In the gimbaled "Lunar Sim Mode," the free-gimbaled turbofan engine was allowed to swivel and was kept pointing downward to Earth's center of mass regardless of the LLRV's attitude; this allowed the vehicle to tilt at the far greater angles that would be typical of hovering and maneuvering above the lunar surface. Despite its ungainly appearance, the LLRV was equipped with a highly sophisticated array of early sensors (mainly Doppler radar) and computational hardware. The system had no specific name, but the effect it produced was called "Lunar Sim Mode." This was the highest degree of hardware-based simulation. It was not a system to unburden the pilot, as an autopilot does, nor was it meant to introduce any sort of safety or economy.