Leeham News and Analysis
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Redefining the 757 replacement: Requirement for the 225/5000 Sector, Part 4.
By Bjorn Fehrm
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Introduction
08 March 2015, c. Leeham Co: In the third part of the article series around the need for a more capable solution for 180-240 seats and 5,000 nautical miles, we compared different clean sheet single and dual aisle aircraft to the Airbus A321LR and Boeing’s 787-8, the two aircraft that form the border to the segment.
We could see that a single aisle aircraft started to have trouble with weight at around 220 passengers using our normalized seating rule set. This would with normal OEM seating rules be around 230-240 passengers. At the same time the dual aisle aircraft becomes stronger the more seats one assumes. The reason is their thicker fuselage, Figure 1, lends itself better to aircraft which passes 50 meters/160 feet in length.
Figure 1. Cross sections for our studied clean sheet designs; NSA6 (New Single Aisle 6 abreast), NLT6 (New Light Twin 6 ab.) and NLT7. Source: Leeham Co.
Their advantages in boarding and deplaning then starts to outweigh their disadvantages in weight and drag. This trend is explored further in this part where we add Cash Operating Cost, COC and Direct Operating Cost, DOC, to the analysis.
Summary
- The trends seen for NAS6, NLT6 and NLT7, our Middle Of the Market, MOM, models in the segment 180 to 240 passengers gets further reinforced when we go to COC and DOC.
- A factor supporting this is the broader spread of fixed and semi-fixed costs over larger aircraft seat numbers.
- Another is that the shorter ground turn-around time for dual aisles increases the utilization for the aircraft, once again forming a broader base for fixed and semi-fixed costs.
- Introducing CFRP for the fuselage brings clear gains in weight and therefore operating costs. Key for its inclusion in the MOM designs will be the manufacturing advances that will have been made by 2025.
Redefining the 757 replacement: Requirement for the 225/5000 Sector, Part 3.
By Bjorn Fehrm
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Introduction
04 March 2015, c. Leeham Co: In the first and second part of the article series around the need for a more capable solution for 180-240 seats and 5000 nautical miles, which we have labeled the 225/5000 Sector, we went through the derivatives we have analyzed as competitors to Airbus A321LR and showed why none of them are effective as a Boeing solution.
We also looked at the wetted area and weight for our common single and dual aisle aircraft. These parameters are the principal components that determine an aircraft’s efficiency given a certain engine efficiency. We also developed the market picture, outlining a substantial market by the time of entry into service of a clean sheet design by 2025, given that certain market requirements could be fulfilled.
We will now project different solutions to the requirements, thereby utilizing the preliminary design part of our proprietary aircraft model. We will look at three different cabin configurations in four different size classes between 180 to 240 seats and calculate size and weights and the resulting efficiency of the different variants. Against the key data for these different aircraft and their operational efficiency we will be able to postulate what will be the next move from Boeing and Airbus in this segment.
Summary
The findings in this our third article include:
- Aircraft capacity and size for 12 different possible aircraft, named NAS6, NLT6 and NLT7 each in the variants 180, 200, 220 and 240 passengers.
- With this collection of characteristics it will be possible to compare the efficiency and costs for the different sizes and to see how competitive a wider dual aisle aircraft will be in this segment compared to a single aisle.
- In a subsequent article will be compare the operational characteristics of these aircraft thereby also covering the increased revenue potential with a dual aisle aircraft compared to a single aisle.