Comment: Lessons Learnt Maintaining The ADF’s Runways

The program has centralised the planning and delivery of minor and capex (capital expenditure) maintenance, by establishing a consistent approach to maintenance and a network-level approach to prioritise works. 

Undertaken annually, the program consists of three elements: 

1. Pavement inspection and design documentation process; 
2. Value management and capex maintenance planning workshop; and 
3. Construction phase, completion and defects liability period. 

Efficient aircraft pavement inspection 

The visual aircraft pavement inspections form an integral aspect of the wider NAPM Program and are undertaken on foot by a two to three-person design consultant team, depending on the airfield size and complexity. At the time of the inspection, physical works are scoped in detail ahead of upcoming maintenance tasks. 

After the visual inspection, airfield stakeholders receive a briefing and a short exit report by the inspection team, highlighting any areas requiring their immediate attention. Program stakeholders receive a detailed Pavement Inspection Report containing the scoped minor routine maintenance tasks and budget estimate documentation. The report also includes a high-level budget estimate of recommendations for a 10-year capex maintenance plan. 

Back in 2010, Beca co-created with Defence a simple, pragmatic and cost-effective condition rating system for asphaltic concrete, Portland Cement Concrete and Interlocking Concrete Block Pavers aircraft pavements. The aim was to use the rating system at each airfield as part of a standard report to better predict deterioration rates and help determine the timing of maintenance treatments. 

The Airfield Pavement Condition Rating System uses relative ratings of 7 (“very good”) to 1 (“failed”), with detailed descriptors to ascertain a relative condition rating for each aircraft pavement area at each airfield. 

The rating system is not as detailed or time consuming as the Pavement Condition Index system, although the condition rating scales adopted are common to both. 

Initially, pavement inspections were documented using digital cameras and site notebooks, with designs and pricing presented using CAD, Excel and Word. Eventually, Beca developed an app that logs observations, defects and maintenance scope with a GPS location by geo-tagging photos. 

Today, Microsoft Office 365, Power BI and GIS reporting are used to analyse and present the data. This has helped Defence to plan and prioritise both routine minor maintenance works and capex maintenance works more accurately and efficiently. 

New aircraft pavement maintenance products and techniques 

Since 2009, the NAPM Program has trialled new maintenance products and techniques. The most successful have included using: 

• Polymer modified emulsion (PME) – Surface treatments in lieu of surface enrichment spray treatments on aged asphaltic concrete pavements. 
• A semi rigid epoxy (with sand) – To repair various PCC defects. 
• Rapid set cement concrete – For localised expedient PCC slab replacements. 
• Micro surfacing – (12mm thick) To cost effectively rehabilitate and restore runway friction on aged asphaltic concrete runway pavements at a relatively low usage airfield. 
• Stone Mastic Asphaltic (SMA) – As an alternative runway surface. 

An annual workshop to support long-term planning 

The annual workshops held between Defence and the design consultant to review the relative condition of the aircraft pavements at each airfield have proven to be extremely valuable. The workshops allow Defence to rapidly determine routine minor maintenance work plans for each airfield and develop an updated 10-year capex maintenance plan for major works, to meet the annual budget. 

Positive benefits in long-term arrangements 

By sustaining continuity with both design consultants and contractors, Defence has been able to capture lessons learnt and use these to drive continual improvement, by putting mechanisms in place to react quickly to urgent maintenance requirements. This has led to less rework and better value for money outcomes.