No 11: Number of planes matter most to overflown communities
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This is the first of a number of blogs I will write on what the aviation industry could do to assist communities impacted by noise.
The main lesson I learnt in over twenty years representing residents under the Heathrow flight paths is that what matters to communities above all else is the number of planes flying over them. Airport communities are usually reluctant campaigners. They want to see less noise and fewer aircraft over their heads. Planes have become less noisy over the last 50 years. That is welcome. But numbers have increased significantly at most airports, particularly since the introduction of cheap flights. It is now the volume of planes which is the big problem. |
Most communities have little interest in how many planes in total use an airport or even how many runways it has; their prime concern is the number of planes overhead. Each person has their own tolerance level but the tipping point invariably involves an increase in aircraft numbers
Of course, there are other factors involved: the noise of each aircraft; its height; how it is flown; the time of day (and, particularly, the time of night); as well as non-acoustical factors. And most airports could do a lot more in rewarding best practice in order to mitigate the impact of many of these things
But, if I am right, that the number of planes is the key factor, it should feature front and central in the when the industry is planning its future. Wherever possible, flight paths should be varied to provide respite.
6 July 2024
No 12: Good Operational Practices Cut Noise
Some airports adopt good operational practices. Many don’t.
There are a number of operational practices which can reduce the noise from planes.
Arrivals
Continuous Descent Approach (CDA)
Aircraft can descend in one of two ways: either in a step-by-step fashion or using CDA. CDA can cut noise by between 2.5 and 5 decibels.
At Heathrow nearly 90% of aircraft use CDA. At many airports across Europe it is hardly used at all.
The angle of descent
International rules require aircraft to land a 3 degree angle. Some airports, such as London City with smaller planes and tall buildings to avoid, are permitted to land more steeply. On their final approach to London City planes land at 5.5 degrees. Heathrow is one of the very few large airports to try a steeper angle. It trialled a 3.2 degree approach. It was operationally possible but only had a small impact on noise levels – up to 0.5 decibel reduction. What could make more of a difference is what is known as a ‘two-segment approach’. This involves planes using a steeper angle – perhaps even 5 degrees – further away from the airport before reverting to 3 or 3.2 degrees for the last few miles as the plane steadies to land on the runway. Until trials have been done it is not possible to be certain of the noise improvements but they could be significant.
Lowering the landing gear
For modern aircraft landing gear is the dominant noise source on approach. When landing gear has been lowered noise levels increase by between 3 and 5 decibels. So, the later landing gear is lowered, the less noise. In order to get a stabilized approach landing gear needs to go down at an altitude of 1000–2000ft, about 2–3 minutes before touchdown. It is difficult for an airport to enforce the point at which landing gear is lowered but it is possible to highlight airlines and aircraft which lower it sooner than necessary. ‘
Departures
Rate of ascent
Common sense would suggest that the faster you climb, in order to get as high as you can as soon as possible, would reduce noise levels. In essence, that’s correct but it is a little more complex. If a plane uses all its power to climb steeply on leaving the runway, that will benefit most communities directly under the flight path. But it has four downsides: it will increase noise for people very close to the airport. It will increase air pollution levels in the vicinity of the airport. It will have a significant impact on the wear and tear of engines. It will spread the noise so that communities living either side of the flight path up to about 4,000ft will get more noise
In summary, the way planes are flown in and out of airports can make a big difference to noise levels. If some airports can adopt good practices, why can’t they all?
15 July 2024
No 13: Will decarbonisation hit aviation growth?
Forecasts from the aviation industry show it expects to grow significantly over the next 20 years. Boeing forecasts that the worldwide number of passenger jets will double to 50,000 planes over the next 20 years. Demand for flights will grow fastest in emerging markets such as India as an expanding middle class embraces air travel.
Boeing argues it has factored decarbonisation into its forecasts. It is confident the increased production of sustainable fuel, technological breakthroughs and operational efficiencies should still allow airlines to reach their decarbonisation goals.
Only time will tell whether it is right to be so confident. Beginning in 2025, fuel uplift at EU airports must contain at least 2% Sustainable Aviation Fuel (SAF). That percentage will increase gradually each year, to 6% by 2030, 20% by 2035, and eventually 70% by 2050. These requirements will apply to all flights originating in the EU, regardless of destination.
This will come at a cost. Even the cheapest sustainable aviation fuel is roughly double the price of kerosene. Although the ramping up of production in the years to come will narrow the gap between the cost of green and non-green jet fuel, in the near to medium term, going green will hit airline finances. Shai Weiss, chief executive of Virgin Atlantic, estimates fares will rise by up to £40.
That is not a huge amount in a world which is becoming richer. Boeing could be broadly right. The cost of decarbonisation will not in itself significantly impact the worldwide growth in aviation.
21 July 2024
No 14: Flying taxis will be noisy
The Paris Olympics are likely to see flying taxis in use.
Flying taxis use six electric motors combined with propellers that can tilt to help them manoeuvre in tight spaces and reach 200mph. They have a 100-mile range between charges, can carry around four people and — at least to begin with — will be piloted.
They will be noisy. A paper (1) produced by internationally-recognised experts for the International Civil Aviation Organisation says “new aircraft technologies for increased mobility are likely to lead to new sources of community noise”.
And it will be a different type of noise. The report found flying taxis “have the potential to alter the community soundscape due to their noise characteristics that are qualitatively different from traditional aircraft.” They will be quieter than traditional planes but they will be lower and the tone of the noise could be more annoying.
The experts compared noise from air taxis with road noise. They found that they were “more annoying than noise from road vehicles when presented at the same loudness”.
We will not just be watching the Olympics. We will also be listening out for flying taxis.
29 July 2024
No 15: Direct train connections between major European cities could be more than tripled using existing tracks
A report published by Greenpeace last month shows that rail connections in Europe could be tripled without and new track required. It analysed 990 routes between 45 major European cities, and found that just 114 routes (12%) are served by direct train connections. There are 305 routes (31%) where a direct connection would be possible using existing tracks. The report found that it would be relatively straightforward to provide a direct connection between these cities.
By contrast the report found that 69% of the routes were served by direct flights. Greenpeace campaigner Herwig Schuster said “It’s time for European governments and the EU to correct this historic imbalance by improving the connectivity and comfort of trains.”
To read the full report: https://greenpeace.at/uploads/2024/07/connectivity_analysis.pdf
4 August 2024
No 16: In praise of a Frequent Flyers Levy
This is the time of the year many people go on holiday. Often to the beach. Many families fly from the Northern European countries to the warmer countries in Southern Europe. For most working families it is something to look forward to. They can only afford to do it once a year. In many cases, just once every two or three years. And they can only afford to do it because of cheap air fares.
I’ve argued in previous blogs that rail fares should be cheaper but at the moment cheap air fares are the only way most families can enjoy their holiday in the sun. A Frequent Flyers Levy would allow these families to take their holiday while increasing the overall level of tax on aviation (at present it is under-taxed as there is no tax on its fuel and no VAT on airline tickets).
How a Frequent Flyers Levy works is this: everybody is allowed one tax-free return flight a year but the level of tax rises with each subsequent flight taken. If would hit the better-off the hardest as 15% of people take 70% of flights
Maybe the revenue raised could go the railways.
More details on the Frequent Flyers Levy
12 August 2024