Am I biased?

In the airliners.net forum there is a discussion about my last blog entry and that I am biased towards Airbus and the GTF and against Boeing and GE/CFM.

Am I? Well, yes and no! I am partially biased - but only by knowledge (where applicable). After all I am an engineer always looking for the best technical solution.
And I am not biased - I have absolutely nothing against the B737MAX itself. In fact, if you look at a posts from June 2011  you will see that I was sceptical that Boeing will do a NSA (New Small Aircraft) but was in favor of the reengining. I am very sure that Boeing will build a very capable aircraft. If the fuel burn improvement comes out as advertised by Boeing, the range capability of the B737MAX-8 will be for sure better than that of the A320 family. The article from Aspire Aviation points it out, although with the same payload as the A320 (150pax) the B737MAX-8 range will be boosted more than 405nm (as this is the range increase at max payload), so the advantage for the MAX is even larger than 3645nm vs. 3510nm.
I have just (and admittedly not just one time) offered my doubts about the LEAP-X concept, especially for the B737, where the fan diameter is restricted. You just can't argue against physics. And I have seen and read that I am not the only one who have doubts - also regarding the LEAP-1A for the A320neo. And in my last blog I just quoted what was stated in the article with some own comments. I will quote now the preamble of this article to underline that these statements are not my statements, but that they seem to be well researched and credible:

(quote)
Before you read this article
In the course of its research Airline Economics has gained direct input from the signatories on both sides of agreements for the aircraft and engines in question, from airlines, original equipment manufacturers and lessors. We also have had input from people involved in deals and engineering input from those working on the programmes. Airline Economics is now aware how much was paid for what, what mistakes were made, and knows who is worried. See Airline Economics, issues one, two and three, 201, for background on these aircraft and their engines. Thank you to those that helped with this article.
(end quote)

Currently I am working on a comparison between the A350 family and the proposed B777-X. I am not done yet, but I can already say that the A350, especially the -1000 will not look too good. The -800 will be (if ever build, what seems to be doubtful) what Michael O'Leary would call a dogs dinner, but falls out of the comparison with the B777-X family anyway and does not look good against the B787 family.
Finally, I am a big fan of the GE90-115B fan - not to forget the rest of the engine!

Even more doubts about B737MAX

I obtained a very interesting article from "Airline Economics", a publication from Aviation News. As it is a subscriber only magazine, I cannot upload the full article, but I will quote some interesting statements of the story called "A question of circumstance":

1. Regarding the engine competition on the A320neo between the GTF and the LEAP-1A: "The end result is that you've got a really big gap between a P&W Neo and a CFMi Neo." To clarify: the gap is in favor of the P&W GTF and Airline Economics is quoting an senior industry expert here, who expects the LEAP to have a 4% disadvantage (what in my eyes is maybe a little bit too much).
2. Regarding engine competition in the marketplace: "Airline Economics learned early last year that

GTF for B737MAX?

Rumors are spilling over and over since the ISTAT Americas conference in March that Boeing is seriously looking at the P&W GTF as a second engine option in addition to the LEAP-1B for the B737MAX. Aspire Aviation has a long article about the ongoing optimisation of the MAX here and Scott Hamilton is quoted in an article by the New Mexico Business Weekly here. A reason for these rumors seems to be the lack of confirmed orders for the MAX so far. There are only three customers who have ordered the MAX, all others only delivered commitments to the Boeing Headquarter so far. Sure, the year is long, so there is enough time for Boeing to convert the commitments to firm and credible orders, especially as Boeing might be keen to make a similar splash with the MAX at Farnborough as Airbus did with the Neo at Le Bourget last year. But as now there are these rumors about a possible second engine, the committed customers might want to wait and see if there is some truth behind them. So firming up the commitments before there is a final word from Boeing (or P&WA) in either way might be a challenge.
Scott Hamilton expects a decision in the next months - that could also coincide with Farnborough...

Doubts about MAX

Last month I wrote a short entry about Ryanair's Michael O'Leary and what his thoughts are about the B737MAX. Well,  when he talks about aircraft, it barely has to do with physics and what the aircraft can or can not do - it always has more to do with the price for his next deal...
But when the "Godfather of Aircraft Leasing", Steven Udvar-Hazy

Definitive LEAP1-B fan diameter!(?)

Yesterday at the ISTAT Americas conference Mike Bair from Boeing revealed that the LEAP-1B fan diameter for the B737MAX now stands at 68.4". When Boeing and CFM for the first time officially announced a fan diameter for the LEAP1-B in November 2011 (Press Release), it was 68", 7" more than the fan diameter of the CFM56-7BE of the current B737NG.
In the meantime there were news in different but reliable media (LeehamNews, aspire aviation) that the diameter went up to 68 3/4" or 68.5". So now it is 68.4" - what does that tell us?

1. Size matters - although Boeing denies that. Well, of course there is a sweet spot for every aircraft/engine combination, as Scott Hamilton writes in a recent column, so you can't go everywhere with fan size. But apparently CFM still tries to maximize the fan diameter of the LEAP-1B so it just fits under the wing and to get the best possible fuel burn for the aircraft. That means that 68" is not the sweet spot, but that is is somewhere higher.
2. It means that the definition of the engine is probably still not finished yet. If the fan size changes, this potentially changes everything else - at least if you want to maximize efficiency of the whole engine. In turn that means that there is still a lot work for Boeing to define to pylon and the pylon/wing interface.

So stay tuned for the next MAX fan diameter...