The ABF does not support the Airservices proposal to lower Class E airspace on the East Coast of Australia

15th February 2021
By ABF President

There have been proposed changes to Class E airspace put forward by Airservices Australia (Airservices).  In broad terms, the proposal outlines a plan to reduce the current Class E airspace lower limit of 8500’ AMSL from Cairns to Melbourne, to 1500’ AGL.


The ABF does not support the lowering of Class E airspace proposed by Airservices Australia because it will make our sport less safe for our members.


This proposal will impact a number of popular hot air balloon flying areas including Yarra Valley, Benalla, Mansfield, King Valley (NE Vic), Leeton, Canowindra, Hunter Valley, Byron Bay, Gold Coast, Ipswich and Sunshine Coast. 


Our sport hot air balloons do not carry transponder equipment in Class E airspace as hot air balloons do not generate any engine-driven electrical power generation capacity to power a Mode S transponder [CAO 20.18 section 9E.3(d) and AIR GEN 1.5 - 13].  I am informed by CASA that the above exemption will carry forward into the CASR Part 131 (rules for Balloon operations) Manual of Standards (MOS).


The overall safety benefit of the proposal will be negated if aircraft exempt from the airspace requirements are operating in the airspace.  We are concerned that hot air balloons operating under VFR and aircraft operating under IFR would be at risk of collision.  ATC  responsibility for IFR to IFR separation does not address this risk.  VFR operations in Class E will still be able to operate without a flight plan or ATC knowledge.


We are also concerned about referencing the base of Class E.  The proposed 1500’ lower limit has been put forward as Above Ground Level (AGL).  This is not consistent with airspace design principles currently in place and is unworkable. It is not feasible for our pilots, or any pilots, to manage an AGL limitation.  The required adjustments to flight path required to avoid an airspace incursion, eg to remain clear of an airspace lower limit, would result in adverse pilot workload; random and unpredictable maneuvers--for all aircraft operating under VFR in proximity to terrain. The existing airspace design principle referencing Above Mean Sea Level (AMSL) for a lower airspace limit relies on positive separation from terrain using a known and unambiguous datum.  A calibrated pressure altimeter, the standard for general aviation and the emergency system for all aviation, is used by ABF pilots. These same systems do not provide a reliable elevation AGL. Assessing height AGL requires interpretation, is subject to error and misjudgement. Even (costly) instruments that would measure height AGL are not certified for navigation to the standards required to be a primary reference for altitude, let alone the basis for separation where responsibility is mutually shared between aircrew who would otherwise refer to common data (QNH and height AMSL).


Furthermore, should the Class E airspace volume Lower Limit be amended to 1500’ AGL, it will also impose a requirement for balloons to carry two VHF handheld radios.  In accordance with CAAP 166-01, where operating in proximity of a relevant aerodrome, balloons are required to broadcast their position and intentions on the CTAF as well as listen and broadcast as necessary.  Under the proposed change, pilots would be operating within both the Class E airspace and CTAF simultaneously between 1500’ AGL and 2000’ AGL within 10NM of the certified or registered aerodrome, resulting in the mandatory requirement to maintain continuous two-way communication on the ATC frequency and CTAF.  Pilots already carry one VHF airband handheld radio and a UHF CB radio (for communication to ground crew). Lowering the lower limit of Class E airspace will drive an increase in pilot workload, confuse the priority and means for position reporting and traffic separation, and pose an avoidable and unnecessary safety risk.


Airservices statements “Class E does not restrict access for VFR aircraft” and that the proposal “fosters equitable access for airspace users”, are incorrect.  Hot Air Balloons engaged in private operations in controlled airspace require CASA permission or a Controlled Airspace Endorsement from the ABF.  The minimum number of PIC hours is 75 before such an endorsement can be issued.  Under the Airservices proposal, these pilots will be limited to 1500’ AGL which means:


  • They will be excluded from airspace which is currently open to them; 
  • They will only have 500’ of airspace, and often less airspace, to fly over populated areas where the minimum overflight is 1000’ AGL (CAAP 157-1); 
  • Over vast areas of Australia, our pilots will be unable to use the upper airspace where winds are vital to steering balloon to a safe locations are available; 
  • The limitation on upper airspace will drive flight operations to low levels, increase average proximity to terrain and obstacles, increasing noise impacts on the general public, increasing noise and nuisance complaints, and posing increased risk to wildlife and livestock that may be easily frightened; 
  • We will be unable to comply with requirements to overfly Sensitive Zones (SZs) without Class E airspace incursion.  There are many SZs in the area that are over 500’ AMSL on the ground with 1000’ overfly requirements which will be impossible to meet.  It is not possible for us to “fly around” an SZ. The principle behind SZs being manageable through use of upper airspace would be compromised; 
  • Inability to navigate over Restricted and Danger areas if the overfly limit is greater than 1500’ AGL;
  • During ab initio training, it will prohibit the ability to carry out a flight to 4,000’ feet AGL and experience terminal velocity descent, both of which are part of our Syllabus for * Practical Flight Exercises, which are carried out to train for emergencies, unless they travel unreasonable distances to operate outside of the affected area; and
  • A significant reduction in safety will occur due to reduced time for adequate decision making for pilots when managing emergencies below 1500’ AGL.


The ABF does not support the proposal as it currently stands and asks that Airservices withdraw the proposal consult more widely on a National Airspace Strategy that would enable industry, the Government, and its agencies, to work collaboratively, to see how various airspace users are required to operate, and to understand the unique circumstances and requirements applying to the variety of airspace users with legitimate and existing rights to operate in Australian airspace. 


The aim of adjusting airspace boundaries should be to achieve an improvement in safety through principles, directions and timelines that do not leave some aviation participants behind and are safe for all airspace users. As designed and consulted this proposal does not pass those tests.

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