Rural airport noise affecting neighbouring property

Q: We have had several complaints relating to a rural air strip that is being used for agricultural purposes, adjacent the boundary of a neighboring dwelling.  The main complaints are in relation to the noise produced by the aircraft in taxing, taking off, flying over the dwelling and loading operations on the site.

Under the RMA section 326 excessive noise does not apply to aircraft operated during or immediately before or after flight.  In our district plan we do not have any specific rules relating to rural airstrips.  Has anyone one come across this situation and managed to resolve it, your advice would be appreciated.

Answers:

A: If the airstrip is authorized under your district plan then only practical control is to encourage a ‘good neighbour’ policy.  I am in charge of **** Airport which has full-on activity and a vector right over the town.  I looked at air-noise boundaries but as no night flights and no jets this would not be any real use and is really costly.

Option of a voluntary regime not to brass neighbours off is best bet. This may include:

• Avoid early/late starts (although they must only operate VFR daylight hours under CAA for airstrips
• If still air conditions use vector away from sensitive areas when taking off
• Once airborne try to use varying flight paths to avoid overflying same place all the time
• If pilots agree try to have ‘no fly days’ eg Sunday

A: Every rural town in the country must have a similar situation to yours. Who was there first, the complainant or the airfield? I dealt with a situation like this when I first came to ****, and I told the complainant that the noise of the top-dresser plane’s engine is really the music of a buoyant farming economy, so get used to it! You could ask the pilots to use only fine pitch on the propellers at all times other than taking off with a full load, as it is the tips of the propeller blades that generates the noise. We have topdressing aircraft using *** Airport all the time, and they fly over my house most of the time, and when the props. are on fine pitch the noise is just a whisper.

A: Good synopsis but the propeller on such aircraft are known as constant speed units and must be in fine pitch for take off to give climb out performance. This is usually a noisy phase. When at cruise height, the pilot adjusts pitch and engine power and the noise reduces. Of course at cruise (straight and level) altitude, the aircraft is well away from houses in most respects (less noise), but in agricultural work the idea (for economics) is to take off, sow the load and get back to the airstrip ASAP so no real height is gained (just avoiding the landscape) and usually power settings remain high. The move away from piston engined aircraft to turbines has brought about some reduction in noise which probably is still not acceptable to many people

As you point out, topdressing aircraft have been around for longer than many of us have been in the job and are very much part of the rural scene and will remain so for some time to come. Most rural dwellers accept the temporary inconvenience of a topdresser flying past their house while the work is done. The bigger picture is rural aerodromes as the likes of Motueka that have been there possibly since when the town was established. We don’t need to go near large regional airports as they have their own noise issues. For the rural town aerodromes however, the CAA rules are that take off and landing be along the extended centreline of the service runway until a height of 500 feet is reached. Then a turn can be undertaken. Conversely, on  the final approach, no turns under 500 feet. It usually goes without saying that weekends will see an increased activity in aircraft movements. All licensed aerodromes/airports have a landing chart approved by CAA. These normally set circuit patterns away from built up areas partially as noise mitigation and also for safety reasons

Local government has not helped in terms of noise complaints in that they continue to allow the subdivision of land near to aerodromes/airports. If allowing such subdivisions then cognisance needs to be taken of the need to set appropriate conditions eg noise proofing of houses, notations on certificate of titles etc

As a pilot, I am aware of these issues and good airmanship will result in the appropriate measures (flying) to avoid inconvenience to others. For example, I frequently fly off a local airstrip and on climb out stay well away from farm houses. CAA rules require a minimum of 500 feet over open ground and 1000 feet over built up areas which results in less noise. Again then, my plea is stop subdivisions for city slickers near aerodromes or put conditions on resource consents in terms of noise or other issues that may relate back to the aerodrome such as runway approaches and side clearances

A: section 16 of RMA still applies, ie the duty to avoid unreasonable noise. What you have to determine is, what is reasonable - not an easy thing to do.

Aircraft noise around airports is usually measured in terms of LDN over a 3 month period. So perhaps not that useful.  Perhaps measurements of Lmax might be helpful? But again, what is a reasonable Lmax level not to exceed?