While the sound of a helicopter may have many rushing to  their windows to  identify the make of the aircraft,  the majority of  people  feel an intense sense of annoyance, or more  accurately, disruption or anxiety. 
​
So, what is  it about helicopters that  is so intrusive, placing  people  and animals outside their comfort zone?​​

The answer is    Infrasound    otherwise known as  the 'fear frequency'.

It's all explained   in the following article   'The Fear Frequency'  by Mark  Pilkington ( The Guardian 6 Oct 2003) 

​​  "Have you ever wondered what a ghost sounds like?"  Engineer Vic Tandy may already know. ​"The key here is frequency: 19hz is in the range known as infrasound, below the range of human hearing, which begins at 20hz. Engineer Vic Tandy  learned that low frequencies in this region can affect humans and animals in several ways, causing discomfort, dizziness, blurred vision (by vibrating your eyeballs), hyperventilation and fear, possibly leading to panic attacks".​

A more recent investigation took place in an allegedly haunted 14th-century pub cellar in Coventry, where people have reported terrifying experiences for many years, including seeing a spectral grey lady. Here Tandy also uncovered a 19hz standing wave, adding further evidential weight to his theory.
In an interesting parallel, researchers have recorded that, prior to an attack, a tiger's roar contains frequencies of about 18hz, which might disorientate and paralyse their intended victim. Is this the sound of fear itself?"

We have uploaded  some articles of interest  on the subject here.  You can  listen to  the sound  of 20 Hertz,  the theoretical minimum frequency a human can hear.

An article     in Vertical magazine 'The science behind helicopter noise — and how the industry is working to reduce it '     identifies  "... two locales where helicopter noise seems to be a major issue. In urban areas, you have a multitude of helicopter operations: law enforcement, medical transport, local news, some business transportation, and tourism. And then there’s the more remote, scenic tourist destinations, where those on the ground object to aircraft interrupting their experience in an otherwise serene wilderness. Typically, helicopter tours are the main source of annoyance in these places.

The  majority of  this  information can be logically applied to  what is anticipated from  heliport activities on 2224 Tully  Mission Beach Road. The  Kestral Aviation  information sheet   states  " We will be predominately using our Bell 206L3 Long Ranger and Sikorsky S-76 helicopters, and on rare occasions, our Bell Medium (212 or 412) fleet when need requires (such as in response to natural disasters).  Vertical magazine informs   "...The  Bell 212 generates high levels of impulsive noise..."

The article  Dynamics of rock arches  shows  a plot of the sound spectrum generated by a two-blade Bell 206 helicopter (below).  In it you see the first frequency peak at 13 Hz with a series of overtones at integer multiples

​Thank you to Margaret Moorhouse  from ASH for sharing this information. 

At the C4 general meeting held Friday on 3rd July, the C4 theatrette was overflowing with community members interested in an update on the court appeal.
 
C4 president, Peter Rowles, recapped on the court process saying the respective parties had lodged their relevant documents  for the appeal,    and that C4’s solicitors had engaged experts in the areas of;

• helicopter operations,
•  planning, and
•  the environment.

 Links to these documents can be seen  in the column to the right and are    part of Steps 1 to 3 of the appeal process (as outlined below*).

Peter reported that although details of the Appeal could not be discussed, he could say that the parties were in discussions.
 
Peter went on to say that Mission Helicopters would have helicopter operations experts design trials to demonstrate the noise levels from the activities being planned for the Heliport site.   This forms part of the directions order within Stage 4 of the appeal process.
 
Council’s Approval for Material Change of Use (MCU) is not only for the Air services (listed below), it also allows for “other related entities operated by the Directors / Shareholders of the applicant/owner” (CCRC Planners Report 27 Jan 2021).  Given Mission Helicopters’ high profile and operational connections across the national and international aviation industry, the reality of the Council’s reprehensible MCU Approval is that Mission Helicopters’ operational possibilities are left wide open.
 
Air Services include:

• The arrival and departure of aircraft;
• The housing, servicing, refueling, maintenance and repair of aircraft;
•  The assembly and dispersal of passengers or goods on or from an aircraft;

Any ancillary activities directly serving the needs of passengers and visitors for:

• Associated training and education facilities; and
• Aviation facilities.

Associated uses including medical transfers, aerial firefighting and search and rescue operations will also be undertaken on an as required basis.

To be relevant to the Mission Helicopters Proposal, the operational trials mentioned by Peter would presumably have to include all the possible operational aspects of the above.
​
Another important consideration is what flight path will the trials be based on?
 
In the CCRC Decision Notice (27 Jan 2021) (where CCRC mistakenly refer to the applicant as Mission Beach Helicopters) the approval conditions state “. the applicant/owner ‘must ensure”…”helicopters will head directly east over the Coral Sea prior to heading towards intended destinations (emergency situations excepted) as per the Mission Beach Helicopters (sic) Approach/Departure Waypoint Flight Plan received by  Council on 14th October 2020…”  Yet the Waypoint Flight Plan received on that date (below left) shows a quite different flight path, angled considerably to the south. The actual direct east flight path (below right) shows the impact zone covers the whole of the Conch Street residential area.

* COURT APPEAL PROCESS 

STEP 1
Appeal Period Notice of Appeal filed
Within 20 business days from notice of decision
 
STEP 2
Notice of Appeal to Other Parties 10 business days from when Notice of Appeal is filed
 
STEP 3
Other Parties may elect to join appeal
10 Business Days from when they receive Notice of Appeal
 
STEP 4
Directions Order
Within six (6) weeks of filing the Notice of Appeal the Appellant must apply for directions
To apply for Directions you have to file an application with the court accompanied by affidavit material confirming that the notice of appeal was served on the relevant parties
 
(The Directions order sets out the steps that need to be completed by the parties before the matter can proceed to hearing and normally includes the following:
- Disclosure
- Confirmation of issues in dispute & request for particulars
- Mediation
- Meeting of experts
- Preparation of expert reports
- Continued case management of appeals by court
- when the matter will be set down for hearing 

STEP 5
Hearing of Appeal
If the parties cannot reach agreement to settle the appeal after the
directions have been complied with, the matter can be set down for
hearing