# How can I calculate the fuel consumption of an Airbus 320-200 at various loads?

I want to know:

1. What is the fuel consumption of an Airbus A320-200 - 180 Seats, at 100% load factor for a distance of 2000 km?
2. What is the fuel consumption of an Airbus A320-200 - 180 Seats, at 80% load factor for a distance of 2000 km?
• Welcome to Aviation:SE! Sep 21, 2014 at 13:08

If you need precise values, you need to provide much more detail. Fuel consumption is affected by many parameters; see this answer for more detail.

For a precise estimate it will be best to employ a simulation software; see the answers to this question for more detail.

If you are just interested in a general estimate, the venerable Breguet equation will already give good results. First we need to know how much difference the 20% in load factor makes: The average mass of a passenger plus baggage for short-range trips is 100 kg, so the zero-fuel mass would be OEW + 18 t = 60.6 t in the 100% case and 3.6 tons less in the 80% case. Allow for 3 t of fuel reserves and plug that into the Breguet equation, using a fuel burn of $b_f$ = 0.000018 kg/Ns and a speed of Mach 0.78, which equates to $v$ = 262 m/s in 11.000 m altitude: $$m_1 = m_2 \cdot e^{\frac{R\cdot g\cdot b_f}{v\cdot L/D}}$$ The L/D should be 18 and for the range we use R = 2000.000 m. $m_1$ is take-off mass and $m_2$ landing mass. This gives $m_1$ = 68.54 t for the 100% case and $m_1$ = 64.66 t for the 80% case. To be realistic, you would need to include different fuel flow during climb and descent, but the real value shouldn't be too far from the 5 rsp. 4.7 tons we get from the Breguet equation.

Note that when you repeat the calculation for 5,700 km range, the take-off mass comes out at 78.7 t for the 100% load factor, which is almost exactly the MTOW of the A-320. With 2.3 t of reserves, the Breguet equation gives you exactly the specified performance of the A-320-200. This should give you some confidence in those results.

• how to understand, what is "e" in that equation? Jan 17, 2021 at 16:08
• @user54312, Euler's number e ≈ 2.71828. Mar 12, 2021 at 4:29

There are a lot of factors that affect the fuel consumption. To answer your question, we have to make some assumptions.

• Cruise altitude = 35000 ft.
• Aircraft flown at LRC (Long range cruise speed).
• Air conditioning normal flow.
• Anti icing off.

In the A320 FCOM there are tables which shows fuel burn and distances covered from brake released to the landing. 2000 km is about 1080 nm and only the heaviest A320-200 can carry 180 passengers. This variant has a maximum take off weight of 78000 kgs.

As we do not have exactly 1080 nm in the table, we have to interpolate. So, at 35000 ft:

5961 kg + 6089 kg = 6025 kg

Now, we have to make adjustments to this figure to find the fuel burn at 78000 kg. Using the fuel correction column.

65 kg + 67 kg = 66 kg

The table is made for an aircraft with a weight of 55000 kg. If there is a fuel burn increment of 66 kg for every 1000 kg increase in weight, then for 78000 kg.

78000 kg - 55000 kg = 23000 kg So,

23 kg * 66 kg = 1518 kg.

• The final fuel burn for an A320 weighing 78000 kgs over a 1080 nm flight is (6025 kg + 1518 kg), which is equal to: 7543 kg

If the aircraft weighs 80% of its maximum take off weight - 62400 kg

The calculation remains the same. We just need to correct it for the new weight. So,

62400 kg - 55000 kg = 7400 kg.

7.4 kg * 66 kg = 488.4 kg.

• The final fuel burn for an A320 weighing 62400 kgs over a 1080 nm flight is (6025 kg + 488.4 kg), which is equal to: 6513.4 kg