Boeing details 737 improvements

With a tip of the hat to Jon Ostrower and his Tweet, here’s a link to some detail about the improvements to the Boeing 737.

Given the Airbus write-up in its advertisement about the MAX, we thought this link will be of more than passing interest.

27 Comments on “Boeing details 737 improvements

  1. Scott,

    The article highlights improvements to the 737NG, which were incorporated earlier this year. The aero improvements will carry forward onto the MAX, but the engine improvements apply to the NG only. The one point that is worth noting is that advertised MAX performance is relative to this improved NG. In other words, the advertised 13% fuel burn reduction is 15% relative to a 737NG delivered in 2011.

  2. Do NOT forget, that all performance guarantees on the MAX, are still subject
    to GE/SNECMA confirmation by Feb. ’13, that there engineers will have
    figured out how to get those guarantees out of the (reduced) 67.6 inch
    (correct me if that is not the exact) maximum fan-diameter!

  3. CM :
    It’s the same package. The -7BE engine plus the aero items is what this article is referencing, all of which are already incorporated onto the 737NG.

    Any weight in the wording change from “for a total of 2%” to “up to 2%” improvements?

    • Boeing has always advertised the improvement as “up to 2%”. Operators who have flown NAMS testing with the airplane in service are seeing a bit better than 2%.

  4. Interesting wording and implications:
    “The CFM LEAP pedigree ensures with confidence the ability to deliver a 15% improvement in fuel efficiency, as compared to the CFM56-7BE, while maintaining the same level of dispatch reliability and life-cycle maintenance costs as the CFM56-7BE.”

    from : http://www.cfmaeroengines.com/engines/leap

    • The CFM56 is the current standard bearer. It shouldn’t surpise us to see it held up as the benchmark. Ask anyone operating single aisle aircraft what engine is the most reliable and lowest maintenance cost… second place isn’t even close. The CFM56-7BE is the standard bearer on 737 for fuel efficiency. Again, baselining an SFC comparison to anything else would be a disingenuous.

      • not what caught my attention.
        The -5B ( and -5C too?) should have better intrinsic sfc than the fan limited -7B(E) variant. ( and we have seen numbers that proove that, right? )

        So what does CFM promise when they write in an blurp convering the 3 versions that efficiency will best the -7BE model by 15% ? .. 15% better thermal (core) efficiency ?

      • The A320’s CFM56-5 has (rough guess) a 10% SFC advantage over the 737-800’s CFM56-7. I find it interesting that the 737 was able to make up that difference aerodynamically, with the blended winglets, smaller diameter fuselage, and possibly a more efficient wing.

    • I don’t know if the CFM56-5 engine is 10% more efficient than the CFM56-7B. One thing is for sure. Fan diameter might not be everything, because as was said before and it’s even been accepted by the makers of the CFM56 engines, the IAE V2527-A5 is about 3% better in fuel burn even though is fan diameter is about 5 inches smaller. So, how do they do it?

  5. TCook :
    The A320′s CFM56-5 has (rough guess) a 10% SFC advantage over the 737-800′s CFM56-7. I find it interesting that the 737 was able to make up that difference aerodynamically, with the blended winglets, smaller diameter fuselage, and possibly a more efficient wing.

    If both types are matched on a per seat basis and seat count delta is 8% that would leave about 2% advantage from the items you mention ( less frontal area, winglets, … ) ?

  6. TCook :
    The A320′s CFM56-5 has (rough guess) a 10% SFC advantage over the 737-800′s CFM56-7.

    If you look at CFM’s SFC Rate/Thrust curve for each engine, the max SFC Rate difference between the engines is achieved if you measure the CFM56-7 at 28k thrust and the CFM56-5 at 55k thrust. Measured at this point, the SFC Rate delta is about 8% in favor of the CFM56-5. However, this is not where these engines are operated when compared head to head on the same mission. When you measure them on a comparable thrust basis, the SFC Rate delta is 1%. Specifically looking at the -800 vs the A320, the average mission thrust (inclusive of derate) for the 737-800 is 3% lower than for the A320. Again, this is CFM’s data.

    TCook :
    I find it interesting that the 737 was able to make up that difference aerodynamically, with the blended winglets, smaller diameter fuselage, and possibly a more efficient wing.

    The 737-800 is lighter than the A320 also. The fact it uses less thrust on the same mission should not surprise anyone. The 737-800 has a larger wing (both span and area) and newer airfoil. It has less fuselage frontal and wetted area, and comparable takeoff weight despite carrying more pax. Physics dictates the A320 will need more thrust to accomplish the same mission.

    • That should say “CFM56-5 at 25k thrust”. Not “CFM56-5 at 55K thrust”. That would make the A320 a bit like the A320! 😀

      • Sheesh! I need to stop typing… That should say “a bit like the 757”. Not “a bit like the A320”. I’ll check in tomorrow morning to see how hard a time I get for this! 😳

      • Thanks CM for your insight. I guess typing that many responses so quickly is was bound to happen. And I’m pretty sure you gonna get called on that. Have a good night, take a good rest and come back with renew energy.

    • the weight advantage of the 738 over the A320 ceo was minor and probably a result of old airworthiness requirements the 737 grandfathered. The higher modqification weight of the MAX will probably make the -8 MAX heavier then the A320 NEO.
      The A320 ceo was more efficient then the 737-800NG at flights longer then 500NM. Also it has better runwayperformance, cargo capability, passenger comfort, noise levels and payload range. However the 12 addiotional optional 12 seats of the 737-800 can be an advantage, if they are filled. Someone said Boeing is increasing thrust on -9 to improve airfield performance.

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