Analyzing each factor to determine its relevance to the noise perceived by someone on the ground from an aeroplane:

• Engine power setting: Higher power settings typically result in more noise due to increased engine output.
• Propeller revolutions per minute: Higher RPMs of the propeller generally produce more noise.
• Position of the landing gear: For aeroplanes, extend landing gear means increased drag, which must be overcome with more propeller thrust and power, so more RPM is required and as a result more noise will be generated.
• Flap position: Similarly, extend flaps means increased drag, which must be overcome with more propeller thrust and power, so more RPM is required and as a result more noise will be generated.
• Flight track: The route the aeroplane takes relative to the observer affects the perceived noise.
• Height above ground: The height of the aeroplane influences the intensity of noise heard on the ground. Higher altitudes typically reduce perceived noise.
• Flight rules: Over congested areas (e.g. cities, towns) the flight rules oblige the Pilot to follow specific routes and/or noise abatement procedures, so as to disturbed the citizens the least posiible

Therefore, the correct option is: 1, 2, 3, 4, 5, 6.