Noise signature proximity warning system and feedback mechanism for aircraft

A method in a vertical takeoff and landing (VTOL) vehicle for reducing a level of noise output, the VTOL vehicle comprising a plurality of vehicle lifter motors and a lifter motor controller for the vehicle lifter motors, the method comprising:

• identifying a VTOL noise level at which the VTOL vehicle can operate at a specific geographical location to not cause a total noise level at the geographical location to exceed a predetermined threshold noise level;
• dynamically determining, for the plurality of vehicle lifter motors, a motor-specific fan RPM and a motor-specific fan pitch that will allow the VTOL vehicle to achieve sufficient lift and not exceed the identified VTOL noise level at the specific geographical location based on VTOL vehicle noise characteristics for the VTOL vehicle and an ambient noise level at the geographical location;
• determining whether the determined motor-specific fan RPM and motor-specific fan pitch for the plurality of vehicle lifter motors will allow the VTOL vehicle to operate within its safety envelope;
• and
• sending a motor-specific fan RPM command and a motor-specific fan pitch command to the lifter motor controller to cause the vehicle lifter motors to operate at the determined motor-specific fan RPM and motor-specific fan pitch for the lifter motor at the specific geographical location when it is determined that the determined motor-specific fan RPM and motor-specific fan pitch for the plurality of vehicle lifter motors will allow the VTOL vehicle to operate within its safety envelope.

Non-transitory computer readable media encoded with programming instructions configurable to cause a controller in a vertical takeoff and landing (VTOL) vehicle to perform a method, the method comprising:

• identifying a VTOL noise level at which the VTOL vehicle can operate at a specific geographical location to not cause a total noise level at the geographical location to exceed a predetermined threshold noise level;
• dynamically determining, for a plurality of vehicle lifter motors, a motor-specific fan RPM and a motor-specific fan pitch that will allow the VTOL vehicle to achieve sufficient lift and not exceed the identified VTOL noise level at the specific geographical location based on VTOL vehicle noise characteristics for the VTOL vehicle and an ambient noise level at the geographical location;
• determining whether the determined motor-specific fan RPM and motor-specific fan pitch for the plurality of vehicle lifter motors will allow the VTOL vehicle to operate within its safety envelope;
• and
• causing a motor-specific fan RPM command and a motor-specific fan pitch command to be sent to the lifter motor controller to cause the vehicle lifter motors to operate at the determined motor-specific fan RPM and motor-specific fan pitch for the lifter motor at the specific geographical location when it is determined that the determined motor-specific fan RPM and motor-specific fan pitch for the plurality of vehicle lifter motors will allow the VTOL vehicle to operate within its safety envelope.