Different approaches to runway maintenance

posted on 10th March 2021
Different approaches to runway maintenance

There’s more than one way to skin a cat, they say – and there’s more than one way for airport operators to ensure that their runways and taxiways remain in good condition and safe for the rigours of airfield operations

Salisbury, Wiltshire, UK-headquartered Jetting Systems Ltd designs and manufactures runway rubber removal machinery that is used to maintain runway friction at some of the largest airports around the world. Its flagship range of airport-focused machines is branded Osprey.

The lateral versions of the Osprey are deep-cleaning units that reduce the need for frequent maintenance and allow the operator to change the width of coverage from inside the cab, while linear Osprey units can be used where fast and frequent access and operations is preferred.

These vehicles use “state-of-the-art technology” and benefit from experience dating back to the 1990s, explains business development executive Daniel Woods. Using only ultra high-pressure water, without chemicals or abrasives, the machines remove rubber, recover all debris and restore runway friction in a single pass, he informs.

Osprey lateral machines are managed by computer numerical control (CNC) technology that enables a single head to move with absolute precision, Woods says. Once the relevant parameters have been set, the process is highly automated. Working parallel to drainage grooves and with water flow concentrated over a much smaller area than larger linear heads, the system is thorough and comprehensive in its rubber removal coverage, he declares.

The Osprey operator selects ‘Jetting On’ and starts to move the unit forwards. Once the minimum speed has been achieved, the rubber removal head starts to track across the front of the machine and is perfectly synchronised with the forward speed of the machine. If the operator reduces forward speed, for example where deposits are heavier, the rubber removal head’s lateral speed slows and more rubber is removed.

The lateral system offers minute adjustments of cleaning width, from 300mm to the current maximum of 2.3m. Selection of rubber or paint removal is possible from within the operator’s cab without any interruption of operations, or the need for any additional tools. The nozzle height (the ‘stand off’ distance from runway to nozzle) is also adjustable from inside the operator’s cab, along with the number of head revolutions per minute (rpm) of the system, water pressure and a host of other parameters that can be altered to suit operating conditions.

Runway lights and expansion grooves are not a problem and line-marking cleaning is also possible. Says Woods: “We are the only manufacturer who can offer both linear and lateral, power take-off (PTO) and auxiliary engine power, hydrostatic and reduction gearbox-driven machines – and are therefore well placed to impartially offer the best solution for any individual airport.”

In fact, he says, Jetting Systems has its machines operating at gateways ranging from small international airports serving less than 4 million passengers a year to some of the busiest airports in the world, where fleets of Ospreys are used nightly to ensure the safe handling of 80 million or more passengers a year.

Friction sweeping
Melbourne, Australia-headquartered Aerosweep specialises in developing and supplying specialty speed sweeping systems for various industries, including the aviation sector. It manufactures FOD*BOSS, a unique way of keeping runways and other pavement area clear of foreign object debris (FOD).

The FOD*BOSS Ultimate is an airfield friction sweeper that has been in use since 1994 at major airports and air bases. Supplying to a wide range of airports, from the world’s largest international gateways to small airfields, as well as its Melbourne headquarters Aerosweep also has speciality dealers throughout the world that can provide expert advice and assistance in identifying the most effective sweeping configuration for each airfield’s needs.

Russell Nicholson, head of sales & marketing at Aerosweep, explains that what makes the FOD*BOSS Ultimate unique among friction sweepers is the patented critical safety features that are built into every unit.

These four safety features work “synergistically”, he says, not only to maximise the FOD pick-up rate, but also to ensure that the FOD is captured within the equipment’s mat and is trapped there throughout the sweeping process. This happens in wet or dry conditions, in high winds, and during high-speed and low-speed sweeps alike.

The FOD*BOSS can operate at speeds up to 35mph/55kph. In practice, this allows a typical runway of 7,500ft by 148ft (2,286m by 45m) to be entirely swept by a single 8ft (2.4m) sweeper in as little as 56 minutes, whereas the Triplex variant of the system can sweep the same area in as little as 21 minutes. (Aerosweep offers Duplex twin-mat trailer and Triplex three-mat trailer variants of the FOD*BOSS, as well as the standard single sweeper model, that can sweep varying widths of pavement.) “That is an important consideration when deciding to shut down a busy runway and when,” Nicholson points out.

The inherent flexibility of the FOD*BOSS also makes it unique, he continues. It is sufficiently agile to be used around parked aircraft and busy apron areas, because it can be towed behind the smallest of electric vehicles.

Not only can the FOD*BOSS handle the big and wide-open spaces where FOD needs to be cleared, such as runways and taxiways, it can also be used as a “fine-grooming tool”, says Nicholson, as it can be deployed rapidly and in smaller and busier areas where certain restrictions may preclude the use of larger systems.

The impact of Covid-19
The pandemic has, of course, had a massive impact on airport operations, and this has had a knock-on effect on suppliers to airport authorities.

While Aerosweep has not escaped the consequences of the Covid-19 pandemic, it has not suffered from the downturn to the same extent as some of its aviation industry colleagues, Nicholson asserts.

“What we have noticed is that airfield maintenance programmes must continue to run and while passenger numbers flying have declined significantly, freight operations have continued, if not increased their proportion of total air movements at airports.

“FOD continues to be created and must continue to be swept and cleared,” he observes. “As a recent customer told me, ‘Passengers aren’t flying, but planes are still operating and airports are still functioning, so we must continue to ensure they have the safest operating environment we can provide’.”

Now, airports are looking for more cost-effective ways of operating, Nicholson believes, adding that the FOD*BOSS is the “perfect tool for achieving a lower cost FOD management program without sacrificing effectiveness and safety”.

At Jetting Systems, Woods confirms that many airport authorities have taken advantage of the unprecedented worldwide reduction in air travel to carry out extensive maintenance of their facilities. In fact, he says, “Our machines have remained busy throughout this period.”
Moreover, some new sales have also been made, Woods recalls. Airport Authority Hong Kong (AAHK) is a valued repeat customer, he notes, which has helped boost sales in Asia in recent years. Four machines have been delivered to other airports in that region over the course of the last year.

Meanwhile, Jetting Systems has continued to make improvements to the Osprey design.

“R&D [research and development] has always been a central pillar of our operations, allowing us to drive innovation in the industry,” Woods states. “Last year, we revolutionised jet bar design, using computer-modelled nozzle placement and sizing to radically improve both rubber and paint removal results.”

The benefits from this include a 30% decrease in water usage and a 30% improvement in performance (as measured in terms of m2 covered per hour). The risk of runway damage has also been dramatically reduced, he notes.

ASI keeps going strong
ASI Solutions is a Wolverhampton, UK-based specialist in asphalt preservation. Best known for its Rhinophalt product, it helps to protect and preserve asphalt and macadam surfaces including those of airfields, test tracks, bridges and car parks.

ASI regards asphalt preservation as a more sustainable and cost-effective way of keeping runways and taxiways serviceable compared with runway resurfacing. Best utilised as a preventative maintenance measure in asset management, it extends the operational life of older asphalt pavements to allow for planned replacement and to arrest aggregate loss.

The Covid-19 pandemic has not stopped the company in its tracks, as Howard Robinson, managing director of ASI, informs. “It has been another positive year for ASI Solutions in the airport sector around the globe, as more and more operators are recognising the benefits of Rhinophalt as a sustainable and cost-effective way of keeping runways and taxiways in better condition for longer, therefore protecting the previous investment they have made in the surfaces of their runways.

“This is crucial at a time when the sector has been through a very tough year on every level because of the pandemic. This also comes at a time when all airports around the world are trying to do more to drive more sustainable ways of working and change their approach to how they deliver airside operations.”

And he observes of this difficult time: “As budgets get cut at airports around the world because of the pandemic, Rhinophalt offers a solution for airports that can’t or don’t want to resurface as frequently as they might have done in the past.”

According to ASI, one application of Rhinophalt produces 97% less carbon than conventional asphalt resurfacing. Moreover, it is the most sustainable asphalt pavement solution available, the company insists, because the technique allows more of the original aggregates in the asphalt to remain in place and to be protected, meaning that resurfacing (which puts new aggregates and bitumen in) need not take place so often.

It significantly reduces FOD caused by surface ravelling (unraveling or fraying). Re-lining can be applied in the same shift. Surfaces can be treated at night, working within tight maintenance windows to minimise operational disruption.

“Airports like Rhinophalt because the work causes minimum disruption, meaning runways and taxiways can be open within just a few hours of [the treatment] being applied,” Robinson declares.

Over the past 12 months or so, ASI has worked at airports including Keflavik and Reykjavik in Iceland, where both taxiways and runways were treated, as well as at several regional airports in the UK, such as Exeter and Cranfield.

Also in the UK, one’s of ASI’s approved contractors applied more than 500,000m2 of Rhinophalt at RAF Brize Norton, the largest Rhinophalt project carried out on any airfield anywhere in the world.

Coming out the other side
Once the aviation industry does start to properly recover from the effects of the pandemic, suppliers to the industry are likely to see the upside. By December last year, Aerosweep was already starting to notice an increase in the number of enquiries it was receiving, Nicholson informs. Moreover, he says: “Interestingly, the benefit of upgrading a sweeper from a single unit to a Duplex or Triplex system is being realised by more and more of our customers.

“Being able to achieve more within the same time frame is the type of productivity benefit every finance or operations team is looking for.”

Jetting Systems’ Woods hears from airport customers that, while much of the world has been hit hard by Covid-19 and global aviation has been largely grounded, there is great pent-up demand for travel both for leisure and business. Wage support schemes have kept many economies going and ensure that people will still travel in large numbers as soon as it is safe to do so, he points out.

“We therefore see a post-vaccine bounce-back restoring passenger numbers in a wave across airports around the world over the coming months and years. It will take a little longer for airport operators to spend tight budgets on runway maintenance. However, as runway friction is safety critical and legally mandated, any airport looking to grow must have a plan.

“We have invested in lower cost alternatives to some of our existing components, to help with reduced budgets, while also bringing key departments in-house, such as control systems where we have developed our own system from the ground up, which can be easily adapted to customer configurations and languages,” Woods points out.

At ASI, Robinson expects more work at Brussels, Gatwick and Sydney airports, as well as in Iceland and markets like Australia – which is expected to continue to develop and invest in its airports.

“In the UK and Europe, we work closely with Allied Infrastructure, which has proved to be a very effective contractor over many years and has completed many Rhinophalt projects on our behalf. It is already reporting strong interest in asphalt preservation for 2021,” Robinson adds.