Leeham News and Analysis
There's more to real news than a news release.
Leeham News and Analysis
- Bjorn’s Corner: Air Transport’s route to 2050. Part 28. June 27, 2025
- Parent agency, FAA often at odds as politics outweighs safety June 26, 2025
- Electric Flight and the Ugly Duckling June 25, 2025
- Engine makers tout “Plan A” but have “Plan B” backups in R&D June 23, 2025
- Bjorn’s Corner: Air Transport’s route to 2050. Part 27. June 20, 2025
Bjorn’s Corner: Air Transport’s route to 2050. Part 22.
By Bjorn Fehrm
May 16, 2025, ©. Leeham News: We do a Corner series about the state of developments to improve the emission situation for Air Transport. We try to understand why development has been slow.
We have since we started in October last year looked at:
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- Alternative, lower emission propulsion technologies, ranging from electric aircraft with batteries as energy source, different propulsion hybrids, and new concepts for jet-fuel and Hydrogen gas turbine engines.
- We have also reviewed recent research on the role of CO2, NOx emissions, and Contrails generated by airliners.
- Two weeks ago, we summarized the present situation around SAF, Sustainable Aviation Fuel.
We examined Alternative 1’s emissions improvement last week and now compare it to the normal improvement in fuel consumption, and thus emissions, that the airline industry is continuously working on.
Improvement in emissions from new generation airliners
We presently have around 25,000 airliners that fly up to seven missions every day of the year. These then consume around 300 million tonnes of jet fuel, generating 950 million tonnes of CO2.
What is the effect of these emissions from the continuous replacement of the oldest of the 25,000 airliners with newer, more efficient ones?
We examine this by the replacement of more efficient new aircraft each year. To get some feel for the segments affected by this replacement, we divide the analysis into Regional, Single-Aisle, and Widebody airliners.
The present generation of more efficient jets is about 20% more efficient than the previous generation they replace. This 20% replacement improvement also includes a small number of two-generation-old airliners.
For the different airliner segments, we can deduce the following replacement pace between 2025 and 2050:
- Regionals: About 200 new regional jets and turboprops were delivered last year. If we assume that the deliveries increase by 3% per year, the regional segment will have 420 deliveries per year by 2050. We assume the new deliveries save 20% of fuel compared with the old ones these replace up to 2040, then 30% as a further improved generation starts delivery. In total, 4,000 regional airliners will be replaced by 2040 and another 3,700 after 2040. In total, these save 13.4 million tonnes in yearly fuel consumption by 2050, which equals 42 million tonnes of CO2.
- Single Aisle: About 900 new single aisle jets were delivered last year. If we assume that the deliveries increase by 5% per year, the Single Aisle segment will have 3,000 deliveries per year by 2050. We assume the new deliveries save 20% of fuel up to 2040, then 30% from 2040 to 2050 as a further improved generation replaces the present aircraft. In total, 21,300 single aisles are replaced by 2040 and another 24,700 after 2040 (these numbers then include growth of the segment). These then save 135 million tonnes in yearly fuel consumption by 2050, which equals 427 million tonnes of CO2.
- Widebody: About 230 new Widebody jets were delivered last year. If we assume that the deliveries increase by 3% per year, the Widebody segment will have 480 deliveries per year by 2050. We assume the new deliveries save 20% of fuel compared with the old ones, replacing them up to 2040, then 30% from 2040. In total, 4,600 Widebodies will be replaced by 2040, and another 4,200 after 2040. In total, we have 8,800 Widebodies replaced. These then save 40 million tonnes in yearly fuel consumption by 2050, which equals 126 million tonnes of CO2.
In total, we save 188 million tonnes of fuel and 595 million tonnes of CO2 during the year 2050. This is, of course, not 188 million tonnes of the present 300 million tonnes of yearly Jet-A1 consumption during 2050.
Some of the delivered aircraft will contribute to growth of the total fleet, so the saving in percent of yearly consumption is not 188 divided by 300.
However, nearly all present older-generation aircraft will have been replaced by 2040, when 30,000 new aircraft will have been added, and the other 32,000 between 2040 and 2050.
Often the progress is not linear, new regulations and technology together with slump in traffic makes the changeover go faster at times (stg III noise). Bigger aircrafts for short routes should be able to reduce fuel burn per pax replacing a number of aircrafts flying the same route at almost the same time. That was the idea of the Airbus A300 (300 pax replacing 2ea 150 seat aircrafts), still no engines at the time nor its structure cold take the cycling so it evolved into a longer range flying aircraft.
I am an interested party and I grant I do not know anywhere remotely to be able to make a correct input.
That said, its my understanding that two single aisle are more efficient than a single wide body due to the mass the wide body has to lift.
So unless the weight is double and not more, then a Wide Body cannot replace the efficiency of multiples of single aisle.
There is pilot savings and some cabin crew saving (I believe) that offsets that a bit.
I think its more like one wide-body is at least 3 single aisle.
Ergo bigger does not work in the classic wide body single aisle split unless its a wide single aisle.
Airlines like Alaska (formaly) and South West etc worked on single aisles for both the cost end and the benefit of flexibility of routes shifting -7/-8/-9 types around.
I’m sure Bjorn has already answered the question about one big airliner vs two little ones, but I can’t remember the answer.
How much pollution is the “too much aeroplane” thing costing us?Unfortunately it’s behind the paywall,but surely there is enough business for a relatively low range A220 500 without worrying about increasing the range considering the average flight of Ryanair,for example.Why isn’t there a wide body specifically designed for short range
The reason is lack of suitable engines, the 757 engines were after much engineering work could handle the cycling with a thrust of approx 42k. First the RB211-535E4 thanks to a big core engine used from the bigger RB211’s. Its large core engine flow and hence reduced HP turbine temperatures made it stay on wing for pretty OK times, then the PW2000 after the ’94 package. For a super light weight 300 seater with just trans continental range you need approx 50k thrust in an engine being able to stay on wing for 15000 cycles. In theory you could use the GEnX core engine and fit a new LP system to get a “half-ass” good 50k engine.
@Grubbie:
“surely there is enough business for a relatively low range A220 500 without worrying about increasing the range considering the average flight of Ryanair,for example.”
Each Airline has its own route structure. Some probably overlap in general, aka United and American. Delta is an odd one in that they cater to the 120 pax area the others avoid. I don’t know if its their MRO ops that allows t hat or ????? They did buy a refinaery once to see if they could make it go in line with their operation (did not but interesting thinking)
Then you have Alaska, Frontier, SW, Jet Blue etc operating usually only one single aisle type (the murky part is the regional feeders)
But you see that Airbus is selling more A321 now than A320 and it looks to be more and more. That has a lot of range (depending on how you pack the passengers) but they buy it anyway.
My only guess is the averages work out. We see some single aisle hops of 200 miles. Seems nuts but I followed one and it did a series of short hops then a fairly long one. Does fueling once save? Or fuel in given location and worth it to carry around?
Anchorage only competition I think is Abbotsford in British Columbia and we beat them on fuel price. We also loose tax money……. yea, hmmmm
An E2-190 has not been sold in the US. Got good range, close to trans continental, seems not enough and or pax carry to be appealing.
US is afflicted with the scope clause but Europe has gone the same way (have not seen a breakdown between regions and if some still more A320).
Its all puzzling.
The wide body cost a lot more and uses a lot more fuel. Boeing was working on a mini wide boy but gave that up.
Cost to build is a lot higher for wide body, lot heavier and the single aisle out competes them by a lot.
China uses the A330 in a regional configuration but they have serious airspace slot issues as the airspace is owned my the military and they won’t give it up. Obviously the government is on board with that. So a wide body can work, enough passengers packed in and slot issues and ………….
Japan does something similar, high density 787s now. Shorter routes. They had high density 747s at one time. Situational specific.