How does MAX compare?

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[UPDATE – Podcast with Scott Hamilton and Jon Ostrower]

We undertook an analysis based on the data available and have to say the Boeing 737MAX looks pretty good.  Indeed, by digging around the 2010 DoT data we were able to establish benchmarks using the 737-800 and A320.  Then we took the improvements promised by the engine makers. The table below illustrates what have been able to derive. A word of caution – the engine OEMs are reviewing our table, and may update our numbers, in which case we will update this post.

Additionally, Boeing and CFM haven’t yet settled on the diameter of the LEAP-1B that will power MAX–66-inches or 68-inches. The difference may be small, but according to Airbus, each inch accounts for about 0.4%  0.5% in fuel burn. (This does not take into account offsetting changes that would be designed into the smaller fan size.)

A key item to consider here is that CFM promises to keep their numbers at least at where they are now on CFM56 but offer better fuel burn and of course a better noise profile.  We see MAX doing over 7% better than the NG.  The A320neo is interesting because the LEAP alone drives down costs by nearly 8%, then throw in sharklets and a aerodynamic tweaks and the number should comfortably exceed 10% over the current A320.  The GTF powered A320neo does even better because PW promises that its new engine will offer significantly lower repair costs since it has a lot fewer parts.

Which of course only provokes the question – how much better would MAX be with a GTF?  We would estimate 1% better than it looks now, bearing in mind it too would be limited to a ~20% smaller fan.

But of course this all depends on the promises the OEMs are making.  CFM has a remarkable record for delivering what it promises and we are confident they will ensure MAX is optimized.  PW is betting its future on GTF and from what we hear the engine is beating goals – they are ahead in testing in Canada with the flying testbed by a lot. So there is reason to be confident in that engine, too.  We feel that engine OEM numbers are sound.  We also, at this stage, believe Boeing will stick to “keeping it simple” with MAX in order to avoid program stumbles. Airbus, from what we hear, is hitting its milestones on neo, too.

If everyone’s numbers are sound, based on our estimate, MAX will be about 2% better than neo in cost per hour.

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25 comments on “How does MAX compare?
  1. 16% fuel saving for the MAX seems to be too much – I guess it is more in the 10-12% range…

    • admin says:

      Yes we also saw that range but decided to go with the number 16% because CFM says they will match GTF. So we chose the more conservative number.

  2. AirBoss says:

    Those 737 cockpit costs make all the difference and have nothing to do with NEO/MAX technology.

    • admin says:

      Right! Which is why we recognize them here, but left them “as is” until there is more clarity. Great pick up AirBoss.

  3. bryan cochran says:

    What cost elements are included in “Pilot Ops?” Not knowing any better, one would think 2 pilots = 2 pilots.

  4. Mayohoo says:

    So it appears there are major differences in Boeing versus Airbus Pilot Ops and Maint Burden costs? Can you elaborate? Do Boeing pilots get paid more? What makes up Maint Burden? And does the analysis take into account seat differential? Is this based on the 66 inch fan versus 80 inch fan?

    • admin says:

      Pilot costs are driven by which airline is flying which plane – legacy costs are higher. No fan size taken into account as there is no data to work with yet.

  5. Jerven Bolleman says:

    Looking at the 737Max A320NEO numbers for LEAP.

    Why is the engine repairs number for A320 LEAP 20% higher for what is basically the same engine on the 737MAX. 189 vs 157. There is something really odd about that number and would seriously investigate the source. Same engine series, main difference being fan size and 20% difference in engine repairs costs?

    If you are comparing plane to plane you need to remove the variables outside the planes. That is pilot costs, as those are carier specific or even pilot specific not plane specific. Fuel ops is mostly plane specific but not quite (seating, mission ranges etc… cargo) .

    Right now the pure numbers are not really comparing A to B. But thats just the opinion of an hobbyist.

    • admin says:

      We removed as many variables as we could. We used US DoT data and cleaned this up to ensure we had the cleanest data possible. For example we excluded US Airways as their A320s have both CFM and IAE engines and their DoT data does not differentiate between them. The numbers produced are as clean as we can make them. Thanks for your comment.

      • Jerven Bolleman says:

        I think that the US DoT data is too weak for airframe comparative studies. Not knowing if there is better public data 😉 It just means that your studies are as weak as the input data. And when the claim is 4% better and margin of error is 25%+ then the valid conclusion is don’t know 😉 Maybe I should buy one of your full analysis’s once and have an in-depth look instead of complaining about free blogs 😉 with interesting information.

        • We at AirInsight agree that USDoT data is often weaker, and more inconsistent than we’d like. But in the lack of better information, some insights can be gleaned from that data that are interesting, and often controversial – which engenders discussions such as this. But until we have better definition of the MAX and the scope of the program from Boeing, it will be impossible to perform an accurate comparison – we still don’t know the fan size of the engine or even aircraft weights as yet. As a result, much of what is being reported is pure speculation, even on the part of Boeing. If the airplane isn’t defined, how can any purported cost differential vis-a-vis competitors be anything but marketing hype?

          We’ll be looking at economic modeling of the aircraft once further data can be gleaned, so stay tuned to our blog for hopefully more definitive information based on better assumptions, once Boeing finalizes their design concept. If you are new to the blog, check our history and you will find a table comparing all of the then existing narrow-bodies, including NEO, NG and CSeries on an apples to apples basis a few months back.

        • leehamnet says:

          We take PayPal….:-)

  6. Oliver2002 says:

    How sad this MAX vs neo offering has become… 4-7% is far too marginal and within normal error. Both promise significant improvements on the current versions but thats about it. Whether either is better can only be said when we actually see data of the test flights.

  7. Guru Josh says:

    You guys are again mixing engine-level SFC with aircraft level fuel burn.
    There is no way that LEAP improves SFC by 16% with a sub-70inch fan. There is no way that either NEO or MAX reach savings of 16% fuel burn on aircraft level. Why don’t you believe Boeing when they say 10-12% in fuel burn? Taking evereything into account, that seems about right.
    There is no way that LEAP reaches the same level of MX cost as the GTF, as the LEAP has to run hotter and/or at higher pressures and/or has to use more expensive/harder to maintain technology to make good on the advantages that the GTF draws from the geared concept.
    Last but not least, I would expect PW to underpromise and CFM to overpromise on their respective SFC figures.
    And there is no way that the MAX beats the CSeries on 500NM sectors, neither on a per trip nor on a per-seat basis.

  8. Guru Josh says:

    And on top, more important than fuel burn, the predominant driver is airframe and engine pricing.

  9. Aero Ninja says:

    I am totally confused.

    If fan size is not known, hence no data is available, how can MAX-LEAP fuel ops savings be estimated at 16%?
    Is not the fuel savings dependant on the fan size? If so, what is the fan size used for this estimate?
    But here is the rub, fan size was not considered.

    What am I missing here?

    • admin says:

      To start with, there is very little data other than marketing info to work with. We decided to put the numbers up to show what it looks like *if* those numbers are to be believed. A key driver for us is that CFM says they will be competitive with PW and no more costly then CFM56. Its true Boeing spoke of 10-12% improvement. We decided to use the CFM number – but you can readily see what happens to the numbers if we go from 16% to 12%.

      We understand the fan size will be around 66-68 inches. Likely around the latter number. In speaking with CFM we are assured they can match or beat the GTF’s fuel burn. CFM has a very compelling history of delivering what they say. They have never missed on the CFM56 and they do not intend to miss on LEAP either. So rather than bet against CFM, we give them the benefit of being equal to GTF at this stage. The 737 is lighter to start with and likely will stay so as MAX. We suspect this is a very important reason fuel burn is lower.

      • Guru Josh says:

        Again: The GTF is an engine. Engine efficiency is measured in thrust specific fuel consumption in lbs fuel / lbs thrust / hour – not fuel burn.
        The “10-12%” inprovement Boeing quotes is aircraft fuel burn measured in lbs fuel burned per mile or per seat-mile.
        A 10-12% improvement in fuel burn is the result of installing an engine with a ~15% improvement in SFC that comes with penalties in weight and drag for the increase in fan diameter and funny shaped nacelles and pylons.

        Hence you cannot substitute the 10-12% number with the 16% number. They are two different metrics.

      • CFM said that the LEAP-1A will be on par with the GTF on the A320neo – they did not say (or I have missed it) that the LEAP-1B will have the same SFC than the LEAP-1A. And they should not say that, as everyone would know that thsi can’t be true…they would also never say that the CFM56-7B would be on par with the CFM56-5B.

        • Guru Josh says:

          LEAP-1B could have better SFC than LEAP-1A in case CFMI would optimize it in Boeing’s favor.
          There’s more ingredients to SFC improvement than fan diameter, e.g. fan and core pressure ratios, turbine entry temperature, or even additional stages…not to mention CFMI business strategy 😉

          • Of course they could have a better SFC with the LEAP-1B- but LEAP-1B implies somehow that they use the same core as for the LEAP-1A/C, so that with a smaller fan (and BPR) SFC will be worse. Thrust levels are lower than for the neo, so OPR does not have to be that high, driving maintenance costs potentially down for the -1B vs. the -1A.

  10. Christopher Dye aka CubJ3 says:

    Given the fact that there is just not enough info to make reliable comparisons between the two planes, perhaps you should have waited before declaring the MAX a winner. All this type of piece does is stimulate defensive reactions from the supporters of each OEM, in this case those who are invested in seeing the MAX as inferior than the A320neo no matter what. The paucity of info allows each side to rely on speculation to vigorously assert their unsupported positions as to what the future hold. The most important piece of info, the MAX’s fan size, will be available soon. I look forward to your update then.

    What is clear is that B had no choice but to avoid the expensive changes to the NG needed to use the full fan sizes of the LEAP X and the GTF (see Richard Aboulafia’s editorial in AviationNow (htttp://, and that this is likely to make the MAX far less competitive, particularly if the GTF turns out to be even better that PW has been claiming. I do not see how B gets half the mkt thru 2030 with just a smaller-fanned LEAP X, unless the MAX is just a transition to the NSA two years later than previously claimed, but Aboulafia thinks that is not in the cards because the tech isn’t there, and so does does Daniel Sang at Aspire Aviation. What a sea change.

  11. John says:

    In your analysis it would seem that a large portion of the cost differential between the two aircraft is based on the significantly higher “pilot costs”. You stated: “Pilot costs are driven by which airline is flying which plane – legacy costs are higher.” I thiink the realities of the marketplace are: the highest paid pilots in the industry on the 737 are at SWA and the lowest paid pilots are at UA on the A320. The pay differential between these two is approximately 53%. The SWA Captain makes 53% more (on an hourly pay basis). It is quite likely that an update to your conclusions may be justified the moment that United achieves a new pilot contract.

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