A320neo and A321neo noise levels

Yesterday the A321neo with the CFM LEAP-1A32 engine was certified by both the EASA and the FAA. The EASA certification document for the aircraft family can be accessed here, the noise certification document is here. The FAA documentation is not online yet.

What strikes me is the high noise level of the A321-251N. The LEAP-powered A321neo is not really less noisy than the CFM56 powered A321ceo, which itself was considerably louder than the V2500 powered A321ceo.

If you compare the highest MTOW version (93.5t) you get a cumulated noise level of 281.7dB for the A321-251N, the A321ceo with the  CFM56-5B4/3 is certified with a noise level of 280.1dB (there are also versions of the CFM56 which have higher noise levels than the LEAP1A though.

The PW1133G in comparison has a cumulated noise level of 268.5dB, more than 13dB less than the LEAP-1A32. Both at the lateral and flyover noise points the GTF is less noisy by about 6dB, the approach noise, where the aircraft itself is the main source, is almost the same for both versions.

I wonder if the values for the LEAP-1A32 are real – or somebody at EASA put some wrong numbers in the document.

The noise values for the A320neo are telling a complete different picture: here, the LEAP powered A320-251N is better than the PW1127G powered A320-271N by 1dB, mainly through lower levels at the lateral noise point.


I wait for some good explanations...

ICAO's new noise and CO2 regulations a miss!

The International Civil Aviation Organization’s (ICAO’s) Committee on Aviation Environmental Protection (CAEP) proudly tells us that they achieved agreements  for future CO2  and noise regulations. Nothing particular is said about the CO2 standards, although they were already heavily criticized by Dimitro Simos, author of the Aircraft Performance Software PIANO when a draft of the plan was outlined in mid 2012.

Surprising engine choice

Last week Aviation Week came out with a story that Philippine Airlines opted for the V2500 and PW1100G for their ordered A321ceo/neo fleet and chose the Trent700 for their new A330-300 fleet.
As of today the whole PAL fleet is powered by either CFM or GE engines this would be a surprise if true - but also shows that PW gained market power through the buy of the RR share in the IAE consortium.
Looking at the A321 in particular though, the choice of the V2500 is not that surprising. From here I pulled all A320 deliveries from this year through August 31: about 84% of all delivered A321 have the V2500. In contrast, about 60% of the A319 and A320 were delivered with the CFM56. As the A320 counts for roughly 76.5% of all A320 family deliveries and the A319 for 7.5%, the CFM56 has the lead with 53.2% market share over the V2500. This is slightly down from 2011, when the CFM56 had a share of 56% for the whole year. In 2009 I found that the market share of the CFM56 was 61%. So with the shift to larger narrowbodies, like I described earlier, the market share in the narrowbody engine segment also changes.

Norwegian goes the American way...

That was a surprise this morning - it was long rumored that Norwegian is one of the airlines that already committed for the B737MAX (100 firm orders plus 100 purchase rights in addition to a follow-on order for 200 B737-800NG), in that case the -8 model. But that they also would order the A320neo (MoU for 100 aircraft plus 50 purchase rights) could not have been expected.
There are two possible explanations that come to my mind as reasons for that decisions to go away from a single-type fleet:

1. They went the AA way (of negotiating), meaning they negotiated with both Airbus and Boeing until they got a deal from both they could not resist to close them both.
2. Their anticipated growth is too large that one of the OEM's could deliver aircraft fast enough to satisfy that growth.

On the other hand it is a little bit discussable if a mixed fleet of B737-800NG and B737MAX-8 would be a single-fleet type anyway. The engines (CFM56-7BE and LEAP-1B) do not have anything in common and Boeing itself talks about 85% commonality between the NG and the MAX. So Norwegian would have had a two-type fleet anyway until the last -800NG would have been phased out. Now that Norwegian gets aircraft from both Airbus and Boeing the last -800NG will be phased out earlier so that the (at that scale) marginally higher costs through having a two-type fleet will be (probably) more than offset by the lower fuel costs.

The next interesting question will be the engine choice for the A320neo. Although the selection of the LEAP-1A to complement the LEAP-1B on the MAX-8 fleet would be the most logical choice, they maybe also go the AA way and buy from both engine manufacturers, like AA did it recently for their A319 (CFM56) and A321 (V2500). So the PW1100G could come into play - the factsheet that Norwegian provided with their press release shows the fan diameter of the PW1100G (81"), but that does not necessarily say anything...

Technology Credibility

During the SWA web press conference about their B737MAX order, the CFM EVP Chaker Chahrour made an interesting statement. Leeham News and Comments has the quote here: "We believe we have much more credible technology than GTF."
Well, apart from that this might have been only some PR talking, I think we should shed some light on the credibility of the quote itself.

LEAP-X core temperatures

I saw this article about the latest design changes to the CFM LEAP engine. I described what I think about the seventh LPT stage and the larger fan diameter in my last blog entry. New to me in this article is, that CFM claims that the LEAP core would run at the same temperatures  - at least turbine entry temperatures - than the CFM56.
Hmm, let's start with pure physics. The LEAP engine will have an OPR of 50 at top of climb. The CFM56-5B has an OPR of 35.5 at the highest (33klbf) thrust setting.
Make it easy and consider the Fan, the LPC and the HPC as one big compressor. The formula to get the compressor exit (or burner entry) temperature is:
T2=(1/etac)*(T1*(P2/P1)^(0.4/1.4)) with P2/P1 being the OPR in this case and etac being the compressor efficiency.

CFM says that the turbine entry/burner exit temperature stays the same, they do not say anything about the burner entry temperature. But to get the highest efficiency, the burner exit temperature (T3) should be
T3=(T2^2/T1), thus being independent from the OPR.
So let's consider that the ratio of T3/T2 should be about the same. Then T2 should be the same, too.
What does that mean for the compressor efficiencies? Well, if T2LEAP and T2CFM56 should be the same, then from the first formula can conclude that:
((OPRLEAP)^(0.4/1.4))/((OPRCFM56)^(0.4/1.4))=etac(LEAP)/etac(CFM56)

Computed, you will see, that the compressor efficiency of the LEAP engine should be 10% higher than that of the CFM56.
Now, the GE90 compressor, on of the predecessors of the LEAP compressor, is thought to have an efficiency of 91%. Let's assume, the LEAP compressor, although considerably smaller, has the same efficiency (which is hard as the relative clearances are larger in a smaller compressor). Then the efficiency of the CFM56-5 compressor should stand at 90%*91%= 82% - if true, the engine would be a disaster.
So, something does not add up here. An engine with a pressure ratio of 50 can't run at the same core temperature as an engine with a 29% lower OPR  - or you did something wrong in your basic layout of the engine.

LEAP-X wins first customers

Just a quick note as I am just coming back from a small vacation and saw the news that LEAP-X reportedly got their first two customers - ILFC for the remaining 40 of their 100 A320NEO order and Virgin America for 30 A320neo. The latter is no real surprise, as it was CFM to loose as the incumbent here. Lessors tend to split their A320 orders anyway, so one could anticipate that, too.
The next very-likely-LEAP-X-powered-A320neo-order should be from AirAsia. As Tony Fernandes wants to convert some of the "Classic"-orders and the current Air Asia order is CFM56-powered, a deal including a conversion of orders is only thinkable with CFM.
Still open are TAM with their MoU for 22 A320neo.
During the Paris Air Show we will probably see orders from Republic and Qatar for the A320neo. I would expect Qatar to choose the GTF, as they are also likely to order the CSeries, which is exclusively powered by the GTF. Republic as one of the existing CSeries customers is also a good candidate for the GTF on the A320neo.

The absent LEAP-X customers

It is very early to say anything about the long-term share of the Geared Turbo Fan and the LEAP-X on the A320neo. On the other hand it is notable that there are now three announced engine choices for the A320neo and none of them is in favour of the LEAP-X.

• ILFC opted for the GTF for at least 60 of their 100 aircraft (MoU with Airbus yet to be firmed up). They have an option for the GTF for the remaining 40 aircraft, but are in talks with CFM about the LEAP-X. Apparently ILFC is not yet convinced to order the LEAP-X.
• Indigo: this can be deemed as an easy win for P&W, although also CFM fought hard for this large deal. Indigo currently uses the V2500 on their "classic" A320.
• Lufthansa: as I wrote in another blog entry, the most important win for P&W so far. They initially ordered the V2500 for their A320, but when RR had problems with the High Pressure Compressor, they had to switch to the CFM56. By the time the A321 was launched, the V2500 then became Lufthansa's choice again - but for the A319 Lufthansa favoured the CFM56. I see two reasons for their split: one is to get a maintenance license for both engines, as Lufthansa Technik is a major player also in the engine maintenance business and saw business opportunities with third parties. Another reason is that the A321 typically flies on longer routes than the A320 and A319, where the better engine SFC of the V2500 plays a bigger role. On the other hand, the CFM56 could have an edge if you fly shorter routes and more sectors a day, as the CFM56 with it's single stage turbine has lower maintenance costs than the V2500. Now Lufthansa ordered the GTF for both the A320neo and the A321neo - a significant move in my eyes!

Now - who is the most probable LEAP-X customer, once ordering the A320neo? GECAS of course! There is no order for the A320neo from GECAS so far - this is no judgement so far, but if Airbus collects some more and potentially large orders by the time of the Paris Air Show in June and GECAS does not come on board, I have a sense that there could be a problem with the LEAP-X - as GECAS should be the customer who has the best insight into the engine.

Lufthansa next in line for A320/A321NEO

Lufthansa yesterday revealed that their supervisory board approved the purchase of 25 A320NEO and 5 A321NEO (along with 5 B777F, which is also significant, but another topic).
Why is Lufthansa significant? Firstly, because they have one of the best technical departments of all airlines. If they order an aircraft, often this is a sign for other airlines with less capable aircraft evaluation departments. Secondly, Lufthansa is the first european full service carrier (or "legacy airline" or "flag carrier", what ever one might call it) to commit to the NEO. Before we had two low cost airlines (Indigo, Virgin America), a south american airline (TAM) and ILFC as the first lessor. So the customer base not only gets larger, it gets more diversed, showing the attractiveness of the NEO for different kinds of business models. Well, not really surprisingly, as money savings (through fuel savings) works in every business model. But Nico Buchholz, fleet manager of the Lufthansa Group was to be convinced that the fuel savings are not eaten up by higher maintenance costs for the engines. The engine manufacturers always claimed lower (PW) or same (CFM)maintenance costs for their new engines when compared to their current offerings. But as the engines are running considerably hotter, I can understand why many are a little bit skeptical. We don't know yet which engine LH will have on their NEO's - but at least one of the two engine makers must have convinced them - or both: remember that LH is currently using CFM56 on their A319/A320 fleet and the V2500 on their A321's.
A few weeks ago Buchholz gave a interview to AirInsight where he talked about the CSeries, the NEO, the GTF and LEAP-X. He sounded very optimistic about the GTF and saw no risk in the gear anymore. Well, he (LH) is already a customer for the GTF via the CSeries...
The NEO order does not include any A319NEO. This might be a sign of more orders for the CSeries from Lufthansa, especially for the CS300, in the future - they still have 30 options along the 30 firm ordered aircraft.
This morning I read an article about the ISTAT meeting early this week which was very interesting: apparently the lessors reversed their opinion about the NEO from what they thought prior to the launch last October. They now think that residual values for the "Classic A320" would not immediately fall. I argued in October 2010 after the ISTAT meeting why I think that would not happen.
Even Steve Udvar-Hazy, who had no good word for the NEO last year, said that it was the "most sensible thing" for Airbus to do.

Geared Turbo Fan scores first

Now we have the long-awaited first battle "GTF vs. LEAP-X" fought out: the GTF (PW1133G) won at ILFC. Today they ordered up to 100 A320NEO aircraft, 60 of them will be powered by the GTF, the rest remains open.
Of course, this is only the first round of the battle, with many more to follow.
But many, including me, would have thought that a leasing company would opt for both engines, leaving their customers a choice.
Per CFM and PW, both engines promise the same reduction in fuel burn.
PW states that the GTF has 20% lower maintenance costs compared to today's engines - probably they compare the GTF to the V2500. CFM says maintenance costs for the LEAP-X will stay where they are with the CFM56 today. So at the end of the day the maintenance cost should be comparable, as the V2500 with it's 2nd HPT stage has "by definition" higher maintenance cost than the CFM56.
So the question is: why ILFC feels better with the GTF than with the LEAP-X - at least for the time being? Do they know something the public does not know?
One could say it is just a matter of a good deal, of course, and that could be right. PW might have offered ILFC a to good deal not to make. But on the other hand, pricing power should be something that CFM could play with - they have thousands of engines in the field and will have many more when the deal comes "online" in 2016 and beyond, so they could cross-subsidize more easily than PW can with their limited market power in the narrowbody market, as they are tied to RR in the V2500 - not to speak about the virtually non-existent widebody market power, where their only really selling products are the GP7000 (in a joint venture with GE) - the PW4000 picked up a little bit recently after it got the Advatage70 package.
Bottom line: it is unlikely that pricing power was the driving factor behind the engine decision from ILFC.
Let's wait for the next battles and their outcomes - maybe we can see some kind of a pattern then...

Oh, and by the way - I would love to know what our "friend" Saj Ahmad from the fleetbuzz Editorial has to say about the GTF now...

Boeing 737 successor

Reportedly, Boeing focuses on a replacement of the B737 rather than doing something with the B777 in the nearer future. Mike Bair, who leads the B737RS studies at Boeing, said in the interview with Bloomberg, that "Six or nine months ago, we were leaning toward a bigger airplane sooner" - meaning that Boeing did not expect Airbus to launch the A320NEO and now finds itself captured between Bombardier on the low-end side of the single-aisle market and Airbus trying to steal traditional B737 customers. So they have to react, but reading carefully the Bloomberg interview and also the latest blog entries from Flightblogger Jon Ostrower makes me believe that they are not really sure what to do. Basically, they have two choices:

• A 6 abreast family sized from 149 seats (to please Southwest Airlines in particular) to around 200 seats. That would mean, that todays -700 would grow a little bit, todays -800 and -900 could stay in cabin lenght were they are today. For sure, cabin diameter has to increase to "speed loading and unloading, with either a wider aisle or possibly two aisles".
• That brings us to the second option: a 7 abreast in 2-3-2 configuration with two aisles. That configuration would make it very hard to please Southwest with a 149 seater. The aircraft's fuselage would be heavy in comparison with a 6 abreast aircraft, as the extra aisle takes extra space you have to buid around. Then the 149 seater would have 22 seat rows, compared to 23 rows of the  -700 with 137 seats in Southwest configuration today. It would not only look like a "Mini Guppy" (see below), but the problem is that in case of "one engine out" the stabilizer has a small moment arm and thus has to have a relatively large area, comprising weight for the larger family members, which does not need the large stab. Vice versa is the case with the wing: to get exceptable runway performance and range for the largest family member (runway performance is today's weak point of the -900ER), the wing has to be sized accordingly, which means extra weight for the smallest member. Of course that's a problem of today's B737 and A320 families, too. But with the CSeries entering the market, which is optimized around 135 seats and trans-con range, there is an alternative available which does not have to make this heavy compromises.

Another question Boeing and the engine manufacturers have to answer (first for themselves) is: what are the improvements in SFC for an engine with an EIS 2010 compared to EIS 2013 (CSeries) or EIS 2016 (A320NEO, C919, MS-21).
Boeing today dismisses the NEO as the 15% fuel burn improvement would be not enough. Remember: fuel is about 40% of Direct Operating Costs (DOC), even for narrowbodies (the numbers in Jon Ostrowers interview with Mike Bair seem to be too low) and it could rise even further. Historically, SFC gets down by 0.5-1% per year. So the best we can expect for a EIS 2020 engine is 4% better than the NEO engines will be - and they could be upgraded as the V2500 and the CFM56 were upgraded several times in their life.
So where could the big advantage in DOC come from?

• Aircraft weight: the new aircraft will benefit from new and lighter materials. If you read the interview, it will probably not be a plastic aircraft but a will get a Al-Li fuselage, like the CSeries.
• Plastic wing with smaller wing area (compared to today's B737) with higher aspect ratio: that leads to lower drag, lower weight and better aerodynamics
• The first two bullets both lead to a lower thrust requirement, directly leading to lower fuel burn.
• Maintenance costs of the aircraft: as the B737 today is the airline's darling when it comes to maintenance costs I can't see where this could get dramatically better
• Maintenance costs of the engines: as these engines will (most probably) be enhanced versions of the LEAP-X and the GTF or something similar from RR (Advantage 2 or 3), the difference in maintenance costs to the NEO engines would be small if at all. They could be even higher, as one way to improve SFC would be to raise OPR and therefore core temperatures.

Conclusion: there will be an cost advantage of the 737RS/797 compared to the NEO: of course. But will it be a step change? I can't see it today. And there are alternatives like the Bombardier CSeries and maybe another 5 abreast model from Embraer - they will decide what to do after Boeing announces their final plans - what could happen in June according to Bair. So in the second half of the year, we should have an announcement from Brasil...watch out!

This is how a 130 seater in a 2-3-2 seat configuration would look like...



Meanwhile there are three more blog entries about the possible 737 successor:
Part II
Part III
Part IV

The Chinese "Threat"

At the Zhuhai Airshow COMAC presented first customers for their C919, aimed to be a competitor to the A320 and B737 narrowbody families.

COMAC said that there are now “up to 100 orders” – a closer look shows that 50 of these orders are firm orders the rest are options.

The four big airlines in China – Air China, China Eastern, China Southern and Hainan Airlines – all ordered the C919. The first three all ordered “up to 20”, probably meaning that 10 for each airline are firm orders and 10 are options.

GECAS is another launch customer – for 5 firm orders and another 5 options. This is not a big surprise, as GECAS is also a customer for the much-delayed ARJ21-700 and GE delivers the engines for both aircraft (as part of the CFM consortium in the case of the C919).

The last launch customer is CDB (China Development Bank) – also not a big surprise, as CDB wants to play a big role in aircraft leasing in the future and signed MoU’s with all civil aircraft manufacturers recently. An anticipated order for the Bombardier CSeries is still in the pipeline and will most probably not being made public during the Zhuhai Airshow, as Scott Hamilton assumed recently.

So the C919 got their first customers – fine! But do we see a threat for Airbus and Boeing here? Not really for the next 10-15 years to come, I would say. Let’s have a look at the numbers for outstanding firm orders from the Chinese airlines that now ordered the C919.

Airbus

Airline	A319	A320	A321	Sum
Air China		28	14	42
China Eastern	5	26	5	36
China Southern		25		25
Hainan	5	26		31
Sum	10	105	19	131

These are the numbers as in the Airbus O&D table from October 31, 2010.

We have to add the order the 50 A320 aircraft which was signed early November.

So the total is 181 open orders.

Boeing

Airline	B737-700	B737-800	B737-900ER	Sum
Air China		50		50
China Southern	25	30		55
Sum	25	80		105

Additionally, there are 46 open orders from other Chinese airlines for the B737 family for a total of 151 open orders.

This is a total of 332 open orders for Airbus and Boeing narrowbodies.

Let’s have a look at the actual aircraft and the (small set of) date given to the media by COMAC at the Airshow (Flightglobals headline was “Comac releases C919 specifications”, which was a little bit exaggerated) and compare it to the A320.

	C919	A320
Span	35.8m	34.1m
Length	38.9m	37.6m
Cabin width	3.90m	3.70m

Efficiency is driven largely by two values: aircraft (empty) weight and engine SFC. Another important factor Is the wing efficiency, expressed in L/D (lift-to-drag ratio).

The thrust needed to power the aircraft in level flight is mass*(L/D).

From press releases it is known that the LEAP-X1C for the C919 is designed for a thrust of 30klbf. The 1.3m shorter A320 has a thrust rating of 27klbf, the engines on the 5.6m longer A321 produce 33klbf of thrust at takeoff.

Weight is not given by COMAC, but the span gives a good indication of the weight. Assumed that the aspect ratio of the C919 wing is not that different from a A320 or B737 wing, the wing area is at least the same as the wing of A320. Wing loading at takeoff (takeoff mass/wing area) is - together with the takeoff thrust – the driving factor for the takeoff length. The C919 is designed with hot-and-high airports in Western China in mind, so wing loading should not be far beyond the A320.

L/D could of course be a little bit better, as the A320 wing design is well over twenty years old.

Given all that we can preclude that the C919 won’t have a large weight advantage against the A320. The main driver for efficiency will be the engine. No doubt that the LEAP-X1C will be far better in SFC than the V2500 and the CFM56-5B on the A320. But what if Airbus does the –NEO? And what if the LEAP-X1C is not the “real” LEAP, as discussed here and elsewhere?

Conclusion: for me, the C919 is not a big deal for the next ten to fifteen years – at least technically. If China decides one day that chinese airlines have to buy nothing but Chinese, then it’s a different story – and confined to the Chinese market and close allies.

By then the Chinese aircraft market could very well cool down, as high speed rail eats into air travel wherever a rail line opens.

Update:
There is a good artice on the Aviation Week Website detailing the C919 orders. It's a little bit different than originally reported by Flight International...