Background
Currently, Plane Sense is preparing for the High Court hearing in November 2025. Our evidence has been filed, including expert witness affidavits challenging claims made by Airways and Wellington Airport about the safety and efficiency of DMAPS. These statements form the foundation of our upcoming Judicial Review.
Expert evidence filed:
Experts in flight operations, instrument procedure design, and air traffic control—highlighting safety issues, increased operational complexity, and risks such as reduced separation between aircraft, and jet aircraft turning toward Mount Kaukau during climb-out - a hazard in engine‑failure scenarios - diverging from best practice flight path design.
An economist from Sapere Research Group—detailing property value losses (on average $20,000–$28,000 per home, some up to $262,000), the total regional economic impact ($248M–$453M), and the wealth transfer from residents to Wellington Airport and airlines.
An international expert on the effects of jet aircraft noise on human health and life expectancy—providing evidence of serious adverse health impacts, a distinct line of expertise not covered by Marshall Day.
Visit our timeline and read expert insights.
The DMAPS Flight Path Change
Implementation: On 1 December 2022, Airways introduced DMAPS, which was approved by Wellington International Airport Limited (WIAL). This was done without consultation with residents in Johnsonville, Broadmeadows, and Khandallah, despite internal notes acknowledging that “the change in flight departure paths may be noticed by some residents in the Johnsonville/Khandallah area.” – [Read more].
WIAL has stated: “In cases like this public consultation isn’t normally undertaken.”
However, in 2018, a different approach was taken with the Performance Based Navigation (PBN) trial. At that time, residents were directly notified by post, public consultation was actively sought, and a 12-month trial period was conducted before final decisions were made. Importantly, the 2018 process specifically welcomed and incorporated community feedback, establishing a clear precedent for how significant flight path changes could and should be managed. – [More here].
Acoustic Reporting
An initial acoustic report commissioned by WIAL in February 2023 concluded that noise levels under DMAPS were “reasonable” and that there had been “generally an imperceptible increase in noise.” Residents strongly dispute these claims, arguing that the actual lived experience has been one of clear and ongoing disturbance. WIAL also initially suggested the new levels represented a return to pre-COVID conditions, a view not shared by affected households.
The methodology of the February 2023 report raises concerns. Only one noise monitor was installed, at a much lower altitude than Broadmeadows (which sits 300 metres above sea level and is among the most affected suburbs). The single monitor was also placed close to the original flight path, rather than in the areas of greatest change—such as Broadmeadows, where noise increases would be most pronounced.
The report analysed just one “single noise event”: a domestic Airbus A320 flight to Auckland. This can be seen as a best-case scenario. WIAL itself accepted that international Boeing 737-800 flights are significantly louder (initially reported as +3dB, later adjusted to +5dB). Yet no single noise events for this type of aircraft—which passes over the suburbs daily, often in the early hours of the morning—were reported. (Like the Richter scale, decibel levels increase exponentially in intensity.)
By comparison, the 2018 PBN trial had a much more rigorous methodology. Four monitors were installed along the proposed flight path, with data collected both before and during the trial period. This provided benchmark data for accurate comparison and allowed the effects on residents to be properly measured before any permanent change was made. The first Marshall Day report on DMAPS, dated 14 February 2023, came only after implementation—leaving no pre-DMAPS baseline for comparison.
Timeline of Events
As part of its investigations, Plane Sense has pieced together a timeline using documents obtained under the Official Information Act (OIA). These reveal how DMAPS was approved and raise questions about the process. [Full timeline here]
8 August 2022: Marshall Day sent WIAL an email with “initial outcomes” of its modelling, noting that more information would follow.
9 August 2022: Just 24 hours later, WIAL formally approved DMAPS, despite not yet having received the full set of modelling.
10 August 2022: Airways’ internal approval deadline. Any delay—or any public consultation—would have prevented the 1 December 2022 implementation date. [See our 1 September 2023 post].
Emails released under OIA (including some omitted from Airways’ original response to Plane Sense) confirm this timeline. WIAL and Airways have declined to comment on the findings.
Plane Sense also believes that DMAPS was not officially approved through the correct legal process, meaning its validity is questionable. After Plane Sense pointed out non-compliance with Civil Aviation Rules, the CAA moved to gazette the new flight tracks in December 2023—over a year after they were first published for use by flight crews. In our opinion, this late gazettal cannot be applied retrospectively and may not be effective in validating the original decision.
Further discussions with the CAA have revealed another concern: the Director’s statutory duty to “monitor adherence, within the civil aviation system, to any regulatory requirements relating to … public health.” The CAA has stated that it considers this obligation to be “minimal.
Noise Monitoring
Following sustained pressure from Plane Sense and the community, WIAL and Airways agreed in April 2023 to install four of the six noise monitors that had been requested in the affected suburbs. Installation of these monitors finally took place between 12 July and 25 September 2023, and data was collected until 26 November 2023. A full sound monitor timeline can be found in our [19 July 2023 post].
Despite the installation, residents have faced ongoing barriers to transparency. Plane Sense has been denied access to the raw data for independent analysis. WIAL has stated that even Ministry of Health public health specialists must submit a formal written request to justify their need before being granted access to the data.
The subsequent report from Marshall Day does not sufficiently assess the impact of single noise events compared with ambient conditions. Instead, much of the analysis averages data over periods when aircraft are not flying (for example, during southerly conditions or overnight). This method risks downplaying the true impact of disruptive noise spikes. Nonetheless, the report generally supports residents’ concerns, noting increases in noise that align with what the community has reported. [Read more in our March 2024 post].
Marshall Day’s conclusions about “reasonable” noise levels are also inconsistent with its founder’s own expert evidence given in an unrelated July 2024 Auckland case. There, he stated that flyovers measuring 75–80 dBA, followed by a drop to ambient levels after 30–60 seconds (similar to levels recorded in the northern suburbs), would constitute a significant adverse effect on residential areas. International research from the World Health Organisation and the U.S. Federal Aviation Administration suggests that 38–52% of people would be highly annoyed in this type of noise environment. In practical terms, residents outdoors or indoors with open windows would be forced to shout or pause conversations for around 30 seconds during each aircraft flyover.
Decibel Levels & Quieter Homes
Noise measurements in the northern suburbs have recorded levels of up to 80 decibels. Despite this, residents are not eligible for WIAL’s Quieter Homes package, which is designed to reduce indoor noise to 45 decibels. WIAL claims that homes under the DMAPS path can expect internal noise of 45–50 decibels, but residents’ own readings regularly exceed this. The increase between background noise and an aircraft overhead can be as much as 20–30 decibels—an abrupt jump that is acutely disruptive.
The February 2023 acoustic assessment reported a general 1–2 decibel increase, while the December 2023 assessment found a 4–5 decibel rise. Because decibel scales are exponential, these increases represent much greater intensity than the numbers alone suggest. The Wellington City Council District Plan recognises airport noise as a “significant environmental effect” that substantially impacts residential quality of life well beyond the airport boundaries.
Plane Sense continues to challenge the reliance on averaged decibel levels in official reports, advocating instead for peak event measurements that more accurately reflect residents’ lived experience.
Environmental Impact
Residents have raised concerns about declining native birdlife, particularly tūī, kākā, and kererū, in suburbs such as Khandallah, Broadmeadows, and Johnsonville. These areas form part of a critical native bush corridor linking Zealandia, Otari Wilton Bush, and Mount Kaukau. Conservation efforts in recent years had seen populations recover significantly, with Wellington City Council recording increases of 270% for kākā, 243% for kererū, and 74% for tūī between 2011 and 2021.
Forest & Bird has confirmed that overseas research shows airport noise can affect birds. However, when asked which environmental agencies were consulted, WIAL did not name any and stated it was “not aware of any evidence” of impacts on birdlife. WCC holds a 34% ownership stake in WIAL. At the same time, the Council’s stated mission is to connect people with nature and encourage its protection.
Meanwhile, WIAL and Airways continue to cite “sustainability” as a justification for flight path changes. Their claims are based on reduced car emissions from altered ground travel, not reduced aircraft emissions, and are less persuasive in the context of rising aircraft departures. In addition, a more recent Airways submission records emission savings below their original forecast figures. Despite this, the higher forecast figure was circulated to residents in October 2024 documentation by Wellington Airport and continues to be advertised on Airways’ website as justification for DMAPS.
Representation & Engagement
The northern suburbs do not have dedicated representation on the Air Noise Management Committee, which currently includes only a small number of Wellington residents from the Eastern and Western Wards. Suburbs impacted by aircraft noise as a result of DMAPS do not feature in WIAL's Airport Noise Management Plan, and DMAPS is not mentioned in Air Noise Committee meeting minutes until March 2023—several months after the new flight paths had already been implemented.
Plane Sense has engaged with both Airways and WIAL, as well as the Mayor of Wellington, who sits on the WIAL Board of Directors. Despite repeated approaches and occupying a noise abatement area, the affected suburbs remain under-represented in airport planning and noise management processes.
Post-Implementation Consultation
Wellington Airport and Airways began a belated consultation process in 2024, more than 16 months after DMAPS had already been implemented.
At meetings and in correspondence, both organisations stated they did not want to revert to the original flight path. Airways confirmed it would not allocate resources to investigate alternatives to DMAPS and that only three options were being considered: maintaining the status quo, moving 6am–7am flights, or reverting to the original flight path. Both organisations identified the current status quo as their preferred option, throwing into question how objective it could be.
The consultation process had significant issues:
Residents began receiving phone calls before the consultation period and, believing these were scam calls, did not wish to provide information.
Many residents in Johnsonville, Ohāriu Valley, and Khandallah did not receive consultation booklets or calls by the original deadline of 11 October 2024. Although the deadline was later extended, this was not widely communicated, and in some cases residents in areas not affected by DMAPS were given additional time to submit feedback.
Analysis of the consultation documentation found it biased towards maintaining the current path (Option 1), while presenting other options less favourably. The safety concerns about DMAPS raised by the CAA were excluded, as were updated Airways figures showing lower emissions savings than the forecast savings promoted in the documentation and on their website.
The December 2023 Marshall Day acoustic report, which supported residents’ concerns, was omitted from the consultation material.
The consultation errors, shifting deadlines, and incomplete distribution no doubt contributed to the result. Despite this, more than 50% of feedback indicated that change was preferred.
Plane Sense maintains that consultation after implementation is not a substitute for proper process. International best practice, as set out in the ICAO Balanced Approach to Aircraft Noise Management (Doc 9829), requires consultation with stakeholders before changes are implemented. The post-implementation consultation undertaken by Airways and Wellington Airport therefore does not meet international standards for transparency, fairness, or accountability.
Current Position
Since March 2023, Plane Sense has attempted to work collaboratively with Airways and Wellington Airport to resolve the impacts of DMAPS, including advocating for the reinstatement of the original over-water departure path from Runway 34.
The concerns extend well beyond noise. They include safety risks identified by aviation experts, health and well-being impacts for residents, and failures of process. Despite a December 2023 acoustic report confirming residents’ concerns and identifying shortcomings in the original modelling, and ongoing CAA concerns over reduced aircraft separation, none of the organisations involved have committed to changing the flight path.
Plane Sense has now filed and served proceedings in the High Court to hold Airways, Wellington Airport, and the Director of Civil Aviation accountable for the public health, safety, and legal issues associated with DMAPS. The Judicial Review hearing is scheduled for 17–19 November 2025.
To meet legal costs and Court disbursement fees, Plane Sense is fundraising and has engaged class action lawyers Dalzell Wollerman to monitor developments, including the potential for a class action claim for compensation by residents affected by DMAPS. [Donations can be made here]. Residents are shouldering the financial burden of holding private and public owned corporations to account for their actions.
Call to Action
Plane Sense is calling for Airways and Wellington Airport to reinstate the over-water departure procedure for Runway 34 as a matter of urgency. Returning to this route would significantly reduce the impact on northern suburbs and help protect the health, safety, and quality of life of the affected community.
This case is about more than aircraft noise or consultation — it is about fair process and accountability. Our legal action seeks to hold both profit-driven corporations and publicly funded organisations — including those charged with aviation safety — to account. These bodies must be transparent, responsible, and act in the public interest, not at the expense of communities.
This time it is our community; next time it could be yours. Plane Sense recognises that the legal action we are taking now can support future communities by establishing accountability and setting a precedent for fairness here in Aotearoa New Zealand. To learn more about other communities around New Zealand facing similar issues, visit our Connections page.
