Seriously, how can flying long distances, non-stop, lower carbon costs?
When you fly long distances non-stop you save time. To fly long distances without stopping to refuel requires carrying more fuel. Carrying more fuel means taking extra space and adding more weight. A high fuel load leads to less space for passengers. Fewer passengers results in higher airfare. The bottom-line is that these flights then become exclusive - where only the rich get on board. That’s not all. This small wealthy club leaves a legacy of high environmental impact. How come?
By logic a single nonstop flight should produce a lower quantity of emissions. Arguably, it could, and yet…be not be the case. Because, long distance non-stop flights – especially those flying the farthest, carrying heavier fuel loads at the expense of fewer passengers, do come at a premium carbon cost.
Experts cite flights between 3,000 and 5,000 km as the most efficient. This is based on fuel burned per kilometer, and of course the type of aircraft; meaning any nonstop ultra long flight emits more carbon than the combined release from the same distance when broken up by travelling two shorter journeys with a stop-over. For example a non-stop flight of 14,000+ km produces approximately 875kg of CO2 per person whereas the same trip with a stopover mid-way would produce 770kg albeit variations between flight paths, passenger load, cargo weight and external conditions (weather).
A nonstop long haul flight requires planes to carry extra fuel, especially when taking off – to be able to go the whole distance. For long and ultra-long flights, some very significant proportion of the fuel is additionally needed to carry the fuel required to complete the flight. In other words, imagine that the fuel was weightless and 50,000 litres were needed. No problem. But since fuel is not weightless, and does carry some hard to ignore weight, the requirement is more, since more fuel has to be burned to carry that 50,000 plus litres. According to a Fuel and Emissions Performance Manager at Airbus, that figure is between 15% and 20% - so to carry 1,000 kg of fuel, an extra 150 kg will be burned.
Fuel burn is crucial to the efficiency of aircraft operation. Empirical analysis shows, that it takes on average ~ 0.2 kg fuel to transport 1 kg of weight over a distance of 1'000 km. It also takes an additional ~ 0.02 to 0.03 kg fuel per 1’000 km for every kg of weight added. That's why above a certain range, it becomes more economical to make stops. This takes into account the fuel alone. Not taking into account the passenger convenience, aircraft cycles, the maintenance cost of the extra takeoff thrust, etc.
It therefore left me a bit perplexed when Quantas Airlines placed an order for 12 new Airbus planes capable of making non-stop flights from Sydney and Melbourne to London or New York possible. This, after making it publicly known, just two months earlier, that the airline had set a goal of achieving net-zero emissions by 2050, and a 25% reduction by 2030. Quantas is also set on grabbing the world’s longest flight record (Sydney to London non-stop / 17,800 kilometers) in 2025, toppling current holder Singapore Airlines, when it does that.
Records apart, I find it hard to reconcile how adding ultra long nonstop flights can aid Quantas Airlines in meeting its boast on lowering emissions – unless it is not really serious or has some ingenious methods of doing so. Time will only tell.
Shafeek Wahab – Editor, Hospitality Sri Lanka, Consultant, Trainer, Ex-Hotelier.
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