11/24/2015

A320neo with PW1127G-JM certified!


Two important milestones for the A320neo program in one week: last week the LEAP-1A and the identical -1C) got it’s certification, both from the FAA and the EASA.  Today, the A320neo got it’s Type Certificate with the PW1100G-JM. The road to EIS is now free and we can expect that the first aircraft will be delivered until the end of the year, almost exactly 5 years after Airbus announced the A320neo on Dec. 1st, 2010.

The A320neo has about 4500 firm orders today, enough backlog for 7-8 years of production.

Now the suppliers, first and foremost the engine suppliers have to show that they can meet the ramp up. This will be no easy Task!

In my last post I wrote that there is a significant downturn in flying time of the two A320neo equipped with the LEAP-1A. Since then it even got worse. In the last week, there was only one flight from the D-AVVB, the 2nd LEAP-1A prototype. The week before also saw less
than 10 hours of flying with F-WNEW and D-AVVB.
I plotted flight hours over calendar weeks, including only the two regular test aircraft here-not the F&R test plane (F-WWIV) equipped with PW1100G-JM. Also not included are the F&R test flights which D-AVVA is doing since November 14th (D-AVVA made 23.5hrs of F&R testing in cw 46 and 20hrs. in cw 47).


Just the day before the certification of the LEAP-1A there was an article published in the Aviation Week, showing a lot of confidence from the program managers at CFM (but I would not expect something different in such article and also the parallel article about the P&W GTF family was quite positive).

There are some interesting points when we compare the EASA documents for the PW1100G-JM and the LEAP-1A.



Weight:

When Airbus launched the A320neo Airbus said that the GTF powered version would have a 1.8t higher OEW than the A320ceo and the LEAP powered version a 1.7t higher OEW.

At the European ISTAT conference in October 2015 Airbus said that the GTF powered version would only be 1.6t heavier but the LEAP-1A powered version 1.9t heavier.



Part of the explanation is that after the launch of the A320neo the LEAP-1A was redesigned to be competitive with the PW1100G-JM. It got a 78” fan (raised from 75”) and a seventh LPT stage to drive the larger fan with the higher bypass ratio. The GTF on the other side is now lighter than expected probably due to the fact that the variable fan nozzle was eliminated due to better than expected fan stability.

If we look at the EASA documents, we can find:

  • 2857.6kg or 6300lbs for the PW1100G-JM
  • “not to exceed 2990kg” or around 6578lbs for the LEAP-1A

Now it not exactly clear how these two numbers compare as we do not know for sure what is in these numbers and what is not. At least this only represents the engine without the nacelle. But there seems to be a difference of at least 250lbs at engine level in favor of the larger GTF. The numbers from Airbus seem to suggest that the difference on aircraft Level is about 300kg or 660lbs. Now a heavier engine also has some "knock down effects" on aircraft level. The pylon for the LEAP-1A for example is probably also heavier than the one for the PW1100G-JM. One can also suggest that the center of gravity of the LEAP-1A is more forward than the one of the GTF, leading to a higher bending moment in the wing. So maybe part of the wings had to be made stronger for the LEAP engine.




Thrust:

The highest thrust version of the PW1100G-JM (for now) delivers 33110lbfs.

There is only one thrust version of the LEAP-1A today (as this is the basic certification, others will follow as for the PW1100G-JM), the LEAP-1A35 and it delivers 32159lbf, about 3% less than the GTF.

So why is it called -35 then? I would have expected a 35klbf rating here. The PW1133G-JM delivers 33klbf of thrust and a 35klbf version delivering the equivalent thrust of 35klbf in non-static conditions is announced.

This is a little bit confusing and we should wait for clarification.


Noise

For the PW1100G-JM powered A320neo there are now also noise data. We can now compare the noise to the two "old " engines, the CFM56 and the V2500.
For this comparison I took the heaviest variants (78t MTOW) with sharklets for the A320ceo engines and the heaviest variant for the A320neo (79t MTOW).


Accumulated Noise
A320ceo with CFM56-5B/4   :  273.2dB
A320ceo with V2500-A5       :  270.0dB
A320neo with PW1127G-JM:  260.8dB


Compared to the accumulated Limit for a 79t MTOW aircraft of 289.6dB the A320neo has a margin of 28.8dB versus Stage 3 or 18.8dB versus the current Stage 4 and 11.8dB versus the future (2018) Stage 14.


Great news for Airbus and P&W. The first aircraft should get delivered in the coming weeks...






4 comments:

  1. Due to the gearbox on the GTF in the front versus the much heavier turbine section on the Leap
    at the rear I'd expect the GG of the Leap to be further back in relation to the GTF.

    Also, it will be interesting to see the weight difference between Leap1-A and Leap1-B.
    The CFM predecessors for both types were on par weightwise afaik.
    Boeing placed quite a bit of PR towards weight advantages of their engine selection.

    ReplyDelete
    Replies
    1. Uwe, I would think that the longer turbine of the LEAP puts the whole engine further to the front and away from the wing, thus bringing the CG more forward compared to the GTF. But I could be wrong...

      Delete
  2. Do you have any knowledge of the current situation of the a320neo?

    ReplyDelete
    Replies
    1. Not really. No idea what is holding up deliveries...

      Delete