As you can probably tell, the tangibility of product performance is something that we’re quite passionate about at Midstream. When we won the Sustainability category at the Inter Airport Europe Awards late last year, it was for the very specific fact that our Modus Tower Series lights can reduce typical energy consumption at airfields by as much as 70%. It’s hard numbers like those that I believe suppliers to the aviation sector need to commit to.

In Dubai, we’ll be showing two other products from our Modus line – the 450 and R1000 floodlights. Both have been specifically designed with the demands of aviation environments in mind, and are capable of delivering significant energy savings while simultaneously improving the quality of an airport’s lighting.

What does that mean? Simply that, when we sit down to talk about the contribution that we can make to an airport’s sustainability targets, we can be incredibly specific about the impact that we can deliver. Through our complimentary design service, we can say with an incredibly high degree of accuracy exactly how much we can help them reduce their energy consumption by, and how fast we can help them achieve net zero as a result.

If that sounds like the kind of discussion you’d like to have around sustainability – one that focuses on real actions, and real results – then we’d love to meet you in Dubai. Why not drop by our stand at 3002.

Annex 14 of the International Civil Aviation Organization’s Aerodrome Design and Operations document provides operators with clear recommendations about the light levels that should be present on an apron. Horizontal illuminance should be 20 lux, with a uniformity ratio of no more than 4:1, and vertical illuminance at 20 lux two metres above the apron.

As helpful as these recommendations are, they are just that: recommendations. Specific legislation does also exist for different territories, and operators should ensure that their environment is compliant with local jurisdictions first and foremost. In North America, the guiding document is IES RP-37-15, airports in the EU should work to the Commission Regulation No 139/2014, and those in the UK must conform with the Civil Aviation Authority’s (CAA) CAP 168.

With tests needing to be taken at night, and on a clear stand, operators are understandably keen to ensure that a lighting audit can be completed as swiftly as possible. Nevertheless, measuring an apron’s lighting levels is a time consuming process – one that needs to be carried out properly to deliver accurate results.

Midstream’s own experiences here lead us to two recommendations. Firstly, the CAA’s approach of using 15 measuring points for small stands, and 25 for large ones, produces perfectly valid results. Secondly, operators should ensure that they secure the area that is going to be measured. Not only does that help from both a health and safety and efficiency perspective, it also ensures that shadows from planes and air bridges don’t interfere with readings.

When measuring or designing a lighting solution, an illuminance grid is used to calculate two things: average overall illuminance, and the uniformity of illuminance in the working area, surrounding areas, and the periphery. Essentially, it helps to show how effective an operator’s lighting is across the entire area being audited – in this case, the apron.

As with lighting levels, illuminance grids also follow certain standards. In the EU, these are laid out in document BS EN 12464-1:2021 – a European Standard that governs the lighting of indoor and outdoor work environments. While EN 12464 does offer clear guidance on the dimensions and ratios that should be used, this is an area in which any qualified lighting provider should be able to offer their expertise.

Simple – but nonetheless important – differences need to be taken into account when switching between horizontal and vertical light readings. For horizontal readings, the lux meter should be placed flat on the ground – or, 0m above the apron from a technical standpoint. The notable exception here is at military sites, where it is sometimes recommended to take horizontal readings at 2m above the apron.

Two metres is also the recommend height for vertical readings in both commercial and military environments. As a result, a tripod should be used to ensure that the meter remains stable while readings are taken. One other consideration here is that the lux meter should be left for around five seconds before taking a reading, to ensure that it gives an accurate measurement. Be sure not to cast a shadow on the receptor, too.

Even simple mistakes when measuring light levels can have a big impact on the effectiveness of the final design. As a result, it’s crucial to ensure that the readings given are accurate. A few basic things to watch out for here include:

• Measuring an apron area that includes multiple stands. Standards require that each stand is measured individually.
• Confusing “minimum” and “minimum average” levels. These are different things, and requirements are based upon the latter value.
• Ignoring uniformity values. A stand may pass based on its average illuminance values, only to fail when assessed for uniformity.

For more on all of the above, as well as detailed guidance on where and how to take light readings and how to select the correct stand category, check out the full recording below.

1. Metal core PCBs are essential
PCBs – or Printed Circuit Boards – are where the LED chips are mounted within a floodlight. PCBs can be made of different materials, and that choice can have a dramatic impact on heat dissipation. Fibreglass (FR4) PCBs, for example, can handle only a fraction of the heat that aluminium equivalents can, for instance. That’s why Midstream uses aluminium or copper in all of its PCBs. If your airport operates in a high-temp area, specifying the need for a metal core PCB in a tender is a crucial first step.

2. Thermal continuity helps to prevent failure
Between the PCB and the heat sink needs to sit what’s known as a “thermal gap interface filler”. This filler connects those units together, and ensures that there aren’t any pockets of air in which heat can build up. This might take the form of a paste, pad, or any other phase changing material, but whatever it is, it needs to up to the task; at Midstream, we use aerospace-grade components for our fillers.

3. Encourage air flow
Away from the PCB, air flow is something to be encouraged. If an LED ends up being completely enclosed, air can’t circulate and the entire purpose of the heat sink is undermined. Here, we focus on designing luminaires that have the greatest number of entry points for air, without compromising the unit’s overall integrity. To do this, we use Ingress Protected (IP) components inside the compartment itself.

4. Paint it white!
Protecting against heat isn’t just about what you do inside the LED. Because white paint reflects sunlight, it can also help to reduce the temperature of a luminaire – by as much as 50°C in some instances. That’s why we use white paint specifically on our LED bodies. Furthermore, we also install solar covers onto our heat sinks. These create a layer between the sun and the heat sink, ensuring that the latter isn’t compromised by solar heat.

5. Test in an accurate environment
In-situ tests can be used to calculate what is known as a TM21 projection. TM21s give manufacturers a clear idea of the lifetime and lumen deprecation of their products, and helps the end user understand the “maintenance factor” – the loss of light that occurs over time. What’s critical here is that any tests are conducted in an environment that reflects the highest possible temperatures, i.e. the middle of the summer.

On the current climate trajectory, extreme heat is only going to become more of an issue as the years go by. In Phoenix, Arizona for instance, temperatures were at or in excess of 110°F on 34 days in 2020 – a new all-time record . That’s a problem, not least because airline operational manuals don’t even include guidance for temperatures above 118° . As this trend continues, airports need to be ready for the impact on infrastructure, as well as fleet.

To find out more about how to ensure that your lighting remains operational in high heat, why not check out download our white paper below discussing the issue? And to learn more about Midstream’s commitment to tackling the cause of extreme conditions, read more about why we’re proud to have signed The Climate Pledge here.

One thing that may help here is Midstream’s own Photometric Measurement guide. It doesn’t avoid the need for airports to undergo a lighting audit, but this free document does provide a step-by-step process which they can follow to test their compliance.

For those airports that do want to improve the quality of their apron lighting, retrofit solutions can be a cost-effective option. But these too can pose their own challenges, particularly when mast infrastructure hasn’t kept pace with expansion elsewhere.

At many airports, the original lighting masts will have been installed during the 1970s or 1980s. A few may have been added along the way, but usually at a slower rate than new stands. It’s therefore not uncommon for an airport that had three masts and five stands in 1980 to now have six masts split across 15 stands, for instance.

That kind of disparity makes compliance very difficult. New regulations state that every stand now requires lighting from two different directions, something that is mathematically impossible in a scenario like the one described above. Rome Fiumicino provides a great example of what is actually needed in a situation like this; a complete overhaul of the mast infrastructure, resulting in an incredibly well-lit airport and huge energy savings in the process.

While reducing the amount of energy used is obviously helpful from a budgetary perspective, innovations in mast technology can also have a major impact on cost. Midstream’s Modus R1000, for instance, utilises a lightweight luminaire and a series of high-performance, asymmetric optic lenses. This, combined with a remote driver configuration, means that the height of the mast can be vastly reduced – resulting in a cost saving of around 70% over traditional models.

While passenger volumes have shown a strong recovery over recent months, they remain low in comparison to pre-pandemic years. As a result, it can be tempting to assume that apron lighting is something that airports can push further down the to-do list. For those who want to improve their bottom line, however, that isn’t really the case.

In our own experiences, many of the airports that have invested in a new lighting system over the past two years have saved a considerable amount of energy by doing so. While airports locked into old sodium-based systems have needed to leave apron lighting running no matter how many flights are departing, those with LED solutions have been able to power them on and off as needed. With the maintenance costs on those old systems also continuing to increase, waiting for business as usual to resume can actually be a false economy.

The payback time on new systems is also getting shorter by the day. Whether it’s a retrofit solution or a completely new installation, an LED lighting system typically starts to deliver a return on investment within two to five years. Even making the switch from first-generation (c. 2011) LED floodlights to next generation ones can offer significant savings.

The main priority, of course, is to get the advice of a company that specialises in the very specific requirements of modern apron lighting. As well as manufacturing our own series of award-winning aviation floodlight solutions, Midstream also offers a complimentary design and consultancy service covering everything from light levels to wingtip clearance.