What are we looking at for 3rd stream, 250kg?
It’s marginal. Think also that the reduced core section will generate more weight savings than the increase brings in. We might end with an even result 😉

That definitely could happen. The third stream is relatively low temp. You could build the necessary structure out of CFRP. The core section is where your dense nickel based alloys are. Even small reductions there counts for a lot with regards to weight.

[USER=”41059″]halloweene[/USER] – The airflow in the intakes doesn’t appreciably change. You could change it, if there is opportunities for further enhancement and internal tolerances within the structure of the plane and such support it. But it doesn’t have to. Having the third stream just changes bypass airflow.

[USER=”39911″]TomcatViP[/USER] – That doesn’t get you a reduction of a factor of two but I’ll take that as a good initial approx.. They will probably reduce the internal volume of the engine core (to get their high pressure ratio) by a slight amount though – like how I first proposed – instead of bumping up the external diameter of the engine (and intake). So, since pressure is a factor it could be slightly more than that. We’re talking small changes though…no need for the drastic difference in the size between the fan and the core seen in airliners because that third stream is compressed and so gives a very high bypass flow. And that means the engine will be very efficient because the fan can run at its optimum speed simultaneously with the LP and HP spools – which cannot happen with the big airliner engines without coupling the fan through reduction gears.

A twenty seven minute podcast on countering hypersonic weapons from Aviationweek.

https://aviationweek.com/defense/podcast-countering-hypersonics

I wonder why is heavy helicopter project going so slowly, cooperation on a concrete project was announced a decade ago. and yet one can read that actual airframes in service aren’t expected for another decade.

They haven’t agreed on the final specs yet. The Russians would like to build a heavier helicopter, roughly similar to Mi-26. That would allow them to use the PD-12V turboshaft engines that they are making. The Chinese favor a smaller design with less lifting performance. The PD-12V is overkill in such a design and so that means using D-136 (Ukrainian) or a Western engine. Either of those approaches complicates things.

The heavy lift helicopter is definitely an area for cooperation, but it ain’t going to move as fast as CR929.

[USER=”58228″]mig-31bm[/USER] – Hard to say. There is very little that is known about it at this time.

[USER=”40268″]blackwood[/USER] – The reveal picture of the static test frame published last year shows the final design. It has what is sometimes called a platypus type exhaust. These types of exhaust nozzles have shown themselves to be a maintenance headache in US designs. So they started flight tests of the drone without it (because they don’t need it for that – as djcross pointed out) while they do materials research to try to avoid that outcome.

It will be interesting to see how quickly this project develops. I’m guessing its service date is more than 5 years out, but we’ll see.

Raytheon delivers NGJ-MB to USN for testing

https://www.flightglobal.com/news/articles/raytheon-delivers-next-generation-jammer-mid-band-po-460125/