3/02/2017

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...

1/17/2017

The future is geared!(?)

The future in commercial aviation is geared, it seems:
Of course P&W and it's partners in the PWW1000G engine thought so when they started to develop their engines for the Mitsubishi MRJ, the Bombardier CSeries, the A320neo and the Irkut MS-21 and the Embraer E2-Jets.
But then, about three years ago, RR started developing their own engine with a geared architecture, calling their product (to be) the "Ultra Fan".
No I read in an article from Aviation Week that also Safran is working on a geared fan engine, under the umbrella of the european Clean Sky initiative, the equivalent  to NASA's CLEEN program.
A cross section of the engine concept can be seen on page 17 of this presentation.
My guess is, all engine concepts that CFM, RR and  P&W will eventually offer Boeing and Airbus for a replacement of today's A320 and B737 will have a gear between the LPT and the Fan!

10/28/2016

A320neo start-up times

The hype was huge when the problem around longer start-up times of the PW1100G-JM went public. Indigo stated that the ~2min. extra time that it took to start up the engines would threaten their Business model as a low cost carrier with high utilization and short turn around times between flights. As I showed in an earlier post this was not very plausible from the beginning. But at airports with tight infrastructure (Frankfurt comes to my mind) it could cause some headache - more for the airport than for the individual airline though - as, if one aircraft blocks the way to the gates as it has to wait until the engines are started, other aircraft have to wait.
Believing what Airbus, P&W and Lufthansa said recently the problem is largely gone now.
Now we can read in a report from airwaysmag about the first revenue flight onboard on the first Frontier A320neo that the that the competing LEAP-1A engine has a "noticeably long startup time". What that exactly means we don't know yet. There was nothing official about that yet, showing once again that the PR Folks at GE, CFM and Safran are doing a much better job than those at P&W.
But maybe someone should tell Qatar Airways CEO Al Akbar about it as the LEAP-1B should "suffer" the same problem before he confirms his order for the B737MAX. Or maybe he already counts on compensations...?



7/27/2016

A321ceo vs. B737-900ER deliveries

After yesterdays order from Jetblue for 30 more A321 (15 x A32ceo and 15 x A321neo with the right to convert to the A321LR), the order from Air Asia for 100 A321neo's and the conversion from Norwegian, now taking 30 A321LR, I looked into the delivery breakdown of Airbus und Boeing's narrowbodies.
Airbus delivered 40% of their narrowbodies as the A321this year so far - Boeing delivered less than 10% of all their B737NG's as the B737-900ER version.
The jury is still out if the pressure for Boeing is big enough to be forced to launch a B737MAX-10 or a clean-sheet MoM aircraft. GE Aviation CEO still has problems with the business case, as one could read in one of the latest editions of Flightglobal (sorry, I have no link, saw it on hardcopy only).
Boeing said they still have time to decide what to do...

7/07/2016

The CFM LEAP LPC issue

For the first time CFM acknowledged, though not directly but through Boeing's B737MAX chief engineer Michael Teal, that the CFM LEAP-1B has an issue with the stall margin of the LPC. This was widely known in the industry for months now and in online forums like airliners.net were some hints to that issue. It is alos clear, that not only the LEAP-1B