The GE9X is the mist ambitious engine ever. It is a full generation ahead of anything else. So delays are a risk of that level of technology.
Could you expand on that?
I echo Zekes remarks to be honest. I see nothing substantially new or ground breaking???
1. CMCs, first engine with the tech in commercial service.
2. High Mach # compressor.
3. Enhanced variable cycle tech. For certain the variable turbine cooling of the LEAP. I see actuators being bought for more, but I do not know the specifics.
4. Far more cooling systems than I've ever seen. The turbine clearance control is two generations ahead of anything I've ever seen. In fact, it is was Lefebvre (one of the great chief engineers of engine design) presented in 1995 to graduate students (me), GE, Pratt, and RR. Apparently another grad student listened and made sure this happened. The problem for me is which of my three grad school friends who attended that lecture made it happen. And which of Lefebvre's variable cycle ideas..
5. Low turbine tech. See LEAP-1B and take it a generation forward. Traditionally, I have been a fan of Pratt being the leader here, but GE stole the right Pratt people. See the incredible efficiency bump of the PW1100G with the low turbine enhancement.
6. Fan blade tip Mach number, without a GTF a required tech for installing the low turbine tech. You get one guess why Pratt is so far behind in this tech.
7. Enhanced materials in combustor (less cooling air)
8. Finally imitating Pratt in modeling airflow through the whole engine. Engines are a system and tweaking how air flows from:
a. Low compressor to high, the GE-90 and TrentXWB botched this to the tune of 1 to 1.5% system fuel burn. Hint, the director if Pratt engine development warned of this botch with the PW6000 early in his carrier. I'm quite certain Steve will never allow this to happen again.
b. High compressor to pre-diffuser. GE was always good at this, modern modeling has allowed a nice fuel efficiency increase.
c. High turbine to low turbine. Seriously, compared to Pratt the LEAP and Txwb are amateur hour here. Seriously? Pratt has only been mocking GE and RR on this since Pratt won the F119 vs. F120 clearly on this tech. I only mention military for the clear' this tech is awesome!' timeframe.
But the people who focus on component efficiency do not get how to maximize system efficiency. 'How can the engine burn 2% less fuel by making the low compressor 1/4% less efficient?'. Because that makes the high compressor and pre-diffuser that much more efficient... Sigh...
Then there are a bunch of little technologies GE is just good at such as pre-diffuserss and shorter combustors. Not to mention fans. GE invests more in fan design because they are the least ready for GTFs. Oops.
The Mach numbers in the high compressor still are not at what that one lecture discussed. That is because bearings and seals are not there (see PW1100G issues).
I like how people who don't understand the internals of an engine mock me. Everything I listed is a generation ahead. Everything presents risk being a generation ahead. That means the first flight delay when risk is realized.
I haven't yet begun to discuss what wing efficiency is enabled by folding wing tips. I could do a wing with 4% better L/D than the A350 wing, but only with the aspect ratio. At least I wouldn't do it without that extension to mitigate the risks. Nor have I discussed Boeing's latest take on electrical subsystems. I'm still scratching my head
I work aerospace R&D. I've been exposed to a lot. If you need an example of when adding weight improves a product, see A330NEO (extended wingspan that is heavy and much heavier engines)