Aerodrome
certification is an option that many small aerodromes may consider particularly
when planning out the physical attributes but certification is not just about
the infrastructure it is also about the aerodrome procedures, documentation and
management all of which are scalable subject to the number of passengers and /
or number of aircraft movements per financial year.
There used to be a few different aerodrome categories but under the new Civil Aviation Safety Regulations (CASR) Part 139 an aerodrome is either:
1. Certified Aerodrome – must comply with CASA MOS Part 139 standards; or
2. Aircraft Landing Areas (ALA) which are uncertified and unregulated aerodromes – it is an operator's and/or the pilot’s responsibility to determine suitability of the facility for use.
If the aerodrome will have Terminal Instrument Flight Procedures (TIFP) to enable operations in other than Visual Flight Rules (VFR) then it must be certified under Part 139.
An aircraft operator of larger aeroplanes (more than 9 seats and a maximum take-off weight of more than 8,618 kg) conducting air transport operations under Part 121 may be subject to operational requirements that may also necessitate an aerodrome to become certified. (CASA, 2023) The need to certify then falls on the type of operations being conducted by the aircraft operator and the commercial negotiations between the aircraft operator and the aerodrome operator. Any change in operator would then initiate the need for new negotiations with the new aircraft operator.
Becoming certified would require ongoing compliance requirements under Part 139 (see relevant CASA site link) and other relevant regulations, which would be scalable based on the number of passengers per annum and being an ALA will mean that the aerodrome operator and the aircraft operators would need to put in place provisions to ensure that the aircraft operator can continue to be compliant under Part 121 subject to the size of aircraft and air transport operations intended. Essentially, either the aerodrome operator or the aircraft operator needs to demonstrate compliance with the relevant Civil Aviation Safety Regulations.
To
provide some context of the ongoing compliance requirements for a certified
aerodrome under Part 139 that would have up to 50,000 passengers per annum the
minimum requirements would be as follows:
1. Aerodrome Manual – develop and maintain scalable to the size of operations
2. Risk Management – develop and maintain a risk management plan
3. Technical Inspections – split inspection of the various elements over every 24 months
4. Emergency Plan - may be covered under local emergency management arrangements
5. Emergency preparedness - emergency induction program
6. Wildlife Hazard Management - wildlife hazard management plan recommended where a high wildlife risk exists at the aerodrome
7. Drug and Alcohol Management Plan (DAMP) – specific and training
8. Management Staff – Accountable Manager and a trained Aerodrome Reporting Officer (ARO) plus manual controller and AIP responsible Person
9. Aeronautical Information Publication (AIP) - Aerodrome details published in ERSA/NOTAM (Airservices Australia)
10. Obstacles - Obstacles within the Obstacle Limitation Surface (OLS) must be monitored
While there is no regulatory requirement for an uncertified aerodrome (ALA) to be inspected and surveyed in accordance with the Part 139 MOS, transport category twin turbine aircraft must meet certain flight parameters, particularly during take-off. There are obstacle clearance requirements for such aircraft, and the only way to determine that these can be met for a particular aerodrome, is to conduct an annual survey of the obstacles.
While certification is not essential for every aerodrome, it does give the aircraft operator peace of mind that the site is being maintained to a prescribed standard and will satisfy the requirements of their own exposition under the flight operation rules and it would also contribute to the aerodrome operator’s safety obligation and commitments.
For more information please see the CASA Advisory Circulars AC 139.A-03v1.1 and AC 139.B-01v1.1 or feel free to get in touch, we can assist with all your engineering or operational requirements.
The cost of aircraft pavement projects is substantially skewed toward the materials required for the construction including water, sand, aggregates, bitumen and cement. These are the primary ingredients required to producing the base materials, asphalt, bituminous seals and concrete essential to build the runways, taxiways and aprons that service an airport, putting aside for now the Airfield Ground Lighting and other support infrastructure. Initiatives that can reduce the impact of these materials, and the associated processes, will likely have the biggest sustainability return.
Flexible pavements are generally made up of crushed aggregates from a quarry to produce the subbase and base layers then topped with hot asphalt also produced using crushed aggregates and combined with bitumen. There are a number of options available to recycle existing pavements through either insitu stabilisation using bitumen or cement, or remove the existing pavement and blend with new materials prior to stabilised installation. The production of asphalt can also reuse these existing aggregates or even incorporate other recycled materials such as waste tyres, plastics and glass. Another alternative to reducing carbon emissions is lowering the production temperature to produce warm instead of hot asphalt.
Rigid pavements are concrete pavements made of crushed aggregates and cement. The production of cement requires significant amounts of energy and consequently carbon emission. Alternative mixes that reduce the impact have come to market using waste products from the energy and steel production including flyash, GGBS and slag to produce geopolymer concrete. There are a number of products on the market and a great example of this was applied by Wagners for the construction of the Toowoomba Wellcamp Airport concrete aprons using Earth Friendly Concrete.
In an effort to transition both industry and community, the Western Australia Government through Murdoch University developed a new geopolymer cement “Colliecrete” using the waste products from the Collie power station: https://concreteinstitute.com.au/new-geopolymer-concrete-industry-for-wa/
Pavement assessment and renewal/upgrade program development
Ensuring an assessment of all the aircraft pavements and associated drainage is completed by a suitably qualified and experienced engineer as part of the annual Aerodrome Technical Assessment (ATI) is a great first step toward understanding the changing condition of your aviation infrastructure and provides the raw materials for the development (or update) of a 10- to 20-year program. The prioritisation and programming of the of works required to ensure that the assets remain in a compliant and safe condition to facilitate efficient aircraft movements without significantly impacting year on year operations is a key deliverable and foundation to the collaboration required to establish a proposed long-term airfield works plan.
Economic and sustainable lifecycle pavement solutions
Following a sufficient understanding of the proposed program ahead which has been agreed in principle operationally, focus can be turned to establishing the most economical and sustainable engineering solutions for each proposed package in the program. The solutions should provide the most economical lifecycle options, that is the lowest cost over the serviceable life of the asset, but short-term funding does not always allow for long term options to be exercised. Ensuring that infrastructure sustainability is considered in the solution will in many cases make more economic sense and contribute to the organisational sustainability targets. See Infrastructure Sustainability Council for information on 3rd party verification.
More collaboration and securing program funding
So the scope, prioritisation of works and the overall estimated cost of the program has been established and provides the foundation for the extensive collaboration required both internally and externally. The budgeting process at an airport is complex in that it not only includes the annual and medium term company budgets but you also need to secure airline agreements to ensure the program is funded at least over the medium term. If the work completed in developing the program was robust and pragmatic, then there should already be a great business case that will support the financial decision making and airline negotiations to commit to the medium-term program.
Delivering works safely within an operational airfield and managing disruption
With an in-principle operational agreement on the extent of proposed airfield disruption and sufficient funds to deliver the next package of work, preferably 2 years if there is runway impact, attention turns to the detailed planning and further communications with impacted stakeholders. Drafting of a Method of Works Plan (MOWP) is a key deliverable and foundation to the communications with impacted stakeholders including airlines, Airservices Australia, emergency services, etc. The MOWP provides appropriate details of the proposed staging of the package and in some cases, there may be critical interface between different packages. This is an important consultation document that will inform what the Final MOWP will look like and the restrictions the construction team will need to consider and price.
Technical oversight of works, quality assurance and defects rectification
The works are being delivered in a safe and considered manner with appropriate Works Safety Officers (WSOs) in place to supervise the aviation safety aspect of the works. Considering the extensive effort, disruption, and financial expenditure to get the project this far, it is time to ensure that once the works are complete there is no need to return until the next cycle of renewal. This requires collaboration between the construction team and the technical team overseeing the works both physically and through review of quality assurance documentation. All going well, there should be no need to rectify defects once completed but realistically there will almost always be minor defects that need to be closed out to ensure they do not deteriorate over time.
The increase in airport revenue keeps airports a viable business to support the communities they serve. In considering the increase in revenue there would also be a balanced consideration of the increase in costs and potential disruption to airfield operations. This may include more effort required to accommodate the aircraft including terminal facilities and security, fuel, and air navigation services. The other key consideration is the impact that the change in traffic is likely to have on the life of the pavement and the timing of renewal or upgrade.
The Aircraft Classification Number – Pavement Classification Number (ACN-PCN), or the new Aircraft Classification Rating – Pavement Classification Rating (ACR-PCR), has been used in making commercial decisions balancing revenue to cost where the difference in rating is not unacceptable (i.e. accepting there will be an associated future cost and disruption to undertake works).
The tipping point in that balance would consider the impact on pavement life and the associated disruption to undertake works to address the structural capacity of the pavement to accommodate the aircraft and traffic change, putting aside gross overloads that create safety concerns which would not be acceptable. The engineering behind understanding the impact requires a good knowledge of the existing pavement structures, the supporting earth, aircraft characteristics, and the current and new traffic.
An increase in tourism, industry or resources can have positive outcomes for the community and their airport. Pavement Engineering considering the safety, cost and disruption implications of welcoming new aircraft is an important part of the commercial decision made by airport operators to enable the desired growth in aviation activity.
The Bonza bonzer is a great example of positive outcomes that would have considered how the introduction of new services impacted those lucky airports.
The weight of a fully charged battery as opposed to an empty one is basically the same as the weight comes from the battery cells not the charge. So in a hypothetical future where electric aircraft replace conventional fuel aircraft (putting aside hydrogen for the moment), we would need to change our aircraft pavement design principles.
Our current design methodology, for airports that have refuelling facilities, is to only consider the departing aircraft in our traffic mix when designing the pavement, and arrival are disregarded due to the significant weight difference as the fuel is consumed during flight. At an aerodrome where no refuelling is offered then every arrival and departure counts in the design process as the load is the same.
If the weight of the aircraft did not change, as in the case of electric aircraft, then we would need to double the traffic considered in the design calculations assuming every aircraft that arrived will depart. In a hydrogen scenario where the aircraft does consume the fuel, our conventional design principles would not theoretically need to change.
So, will electric aircraft ever get to a size that counts in an airports traffic mix for the design process? Well, the 100-passenger aircraft Wright Spirit based on the BAe 146 platform seems to be looking at the options.
Photo: Wright Spirit Website (https://www.weflywright.com/)