Do the NEO and MAX live up to their promises? |

The Airbus A320neo and the Boeing 737MAX families have substantial backlogs, as they promise better fuel efficiency than earlier models. New engine technology with the CFM Leap and Pratt & Whitney GTF promises 15-16% better fuel efficiency than the older CFM-56 and V2500 engines they replaced. But do they live up to their promises? The concept of a re-engined is attractive on many fronts. The airframe essentially remains the same and familiar to existing mechanics. Pilots can complete transition training within just a few hours rather than weeks, and the aircraft is compatible with existing gates and ground infrastructure. A simple one-for-one replacement is very attractive for an airline. If we look at an older model and a re-engined airplane, crew costs are likely the same; maintenance costs will be similar for the airframe, engine maintenance will be competitive on a power-by-the-hour contract with an OEM, and infrastructure costs will be similar. The major difference is fuel burn. So the big question is, how much better in fuel burn are the neo and MAX than the ceo and NG models they replace? Using data from airlines in North America, Europe, and the Middle East from the Skailark database, we examined actual data, in this case, 2019 through the first half of 2023, and observed how well the aircraft performed. We have chosen to utilize data from airlines that operate both ceo and neo, or NG and MAX aircraft of the same type to ensure an apples-to-apples comparison, as it is likely that new models replaced older ones with those carriers. For the A320neo, we utilized data from Aegean, Aer Lingus, Austrian, British, easyJet, Eurowings, Frontier, Gulf Air, Iberia, Jazzera, Lufthansa, SAS, Spirit, Swiss, TAP, Turkish, Volaris, Vueling and Wizz Air. Similarly, for the A321neo, we utilized data from Aegean, Aer Lingus, Air Arabia, Air Transat, American, British, Delta, easyJet, Frontier, Gulf Air, Iberia, jet2.com, Jet Blue, Lufthansa, SAS, Saudia, Spirit, Swiss, TAP, Turkish, Volaris, Vueling and Wizz Air. For the 737 MAX 8, we utilized data from Aeromexico, American, ElAl, Flair, Fly Dubai, LOT, Oman Air, Ryanair, Southwest, Sun Express, Swoop, Turkish, United, and Westjet. For the MAX 9, we utilized data from Alaska, Turkish, and United. We are assured of consistent data reporting and “apples-to-apples” comparisons with those airlines. We examined aircraft fuel efficiency using two metrics. The first metric is fuel burn per block hour; the second is available seat miles per gallon. We will begin alphabetically with the Airbus family and then show the Boeing family. Of course, we lack data to validate Boeing projections for those forthcoming models, with the 737-7 MAX and 737-10 MAX not yet in service. Utilizing Skailark data, we analyzed the difference in fuel economy between the A320ceo and neo, the A321ceo and neo, the 737-800NG and the MAX 8, and the 737-900 and -900ER with the MAX 9. Our results were surprising, with one model showing less improvement than expected and others showing substantial gains. The following table summarizes our findings: The A320neo does not show as substantially improved over the A320ceo as we expected. Fuel burn per block hour averaged only a 5.5% improvement, while ASMs per gallon improved 12.9%, with a portion of that gain from more dense interior layouts. With expectations for 10%-15% gains at introduction, the A320neo does not appear to live up to its promise and has fallen behind the A321neo in Airbus sales. The direct competitor, the 737 MAX 8, showed a bigger improvement over the 737-800NG, with an average 11.7% benefit in fuel burn per block hour and a 17.3% improvement in ASMs per gallon, with a portion of that gain from more dense interior layouts. The 737 MAX 8 has benefitted substantially from the re-engining. The Airbus A321neo shows significant gains, with an 18.9% improvement in fuel per block hour and a 33.4% improvement in ASMs per gallon. The improvement in fuel per block hour is significant and may be assisted by longer-range operations that build ASMs faster given more time at cruising speeds. Nonetheless, the improvement in ASMs per gallon is substantial and explains why the A321neo has become the best-selling commercial aircraft. The 737 MAX 9 also shows substantial gains over the 737-900 and -900ER. Unfortunately, the -900 and -900ER have runway performance issues that detract from their popularity. The MAX 9 fixes the prior issues, enables full payload long-range flights without restrictions, and substantially improves over the previous models. The MAX 9 shows a 21.4% improvement in fuel per block hour over the older -900 and -900ER models and an improvement in ASMs per gallon of 30.9%, nearly that of the A321. With the MAX 10 planned for introduction that will be larger and more efficient than the MAX 9, the MAX 9 has not been as successful as Boeing would have liked, with many potential customers switching to the MAX 10. But until it enters service, we can’t verify the projected economics for that aircraft. The Bottom Line Re-engining can generate substantial fuel economy and environmental benefits over earlier models. The significant fuel cost reduction for the A321neo has resulted in the aircraft overtaking the A320 to become Airbus' best-seller and the best-selling aircraft model worldwide. Strong performance improvement is a reason for that success. The MAX aircraft are also a significant upgrade over the older NG series. Still, the MAX has been tainted by the two fatal accidents early in the program and is unlikely to catch Airbus or the A321neo sales levels to capture market leadership. The A320neo is underperforming based on fuel burn data from North America, Europe, and the Middle East airlines. Airbus has a potential alternative to the A320neo in the A220-500 design, which could be quickly introduced given that a complete design package was completed by Bombardier when it certified the CSeries. Three stretch models were contemplated, and design details were captured using computer-aided engineering while the first two models were introduced. As a result, an A220-500 could be quickly resurrected. If Airbus launched the button on the A220-500, Air France and Delta would likely be immediate launch customers. That new technology aircraft would compete favorably with the MAX8 and provide a growth alternative for A220 customers with fleet commonality. Re-engining is often a good idea but doesn’t always provide optimal results. The A320neo, while still a strong performer, might not be the only answer for A320ceo operators. Aerodynamic technology, such as Tamarack active winglets, could likely deliver a 7% improvement in fuel burn, better than the A320neo to A320ceo improvement of 5.5% on a block-hour basis. But three successes out of 4 aren’t bad for the current re-engined narrow-body models from Airbus and Boeing.

US Flight Planner - US DoT On-Time Data	Airbus vs Boeing - Official OEM Data
US Airline Schedule Performance - US DoT Data	Daily OEM Production & Deliveries -

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