While C version (Comac) is a bit different animal, A version is pretty similar. Boeing (with its lower gear) required different fan, but otherwise, they're very similar (if not identical). Actually, it's the A and C that are similar. They have approximately the same size, thrust ratings and core st...Jump to post
The midway arrangement might be less susceptible to deep stall conditions. That's a possible advantage.Jump to post
Being an engineer myself I can say that, in general, overengineering is indeed a wast of money and resources/weight, maybe. Now, I'm not presuming to know more than GE about their own engine, and I'm sure that there are good reasons for it being as it is. It's just that 20%+ seems like a rather high...Jump to post
Its very likely. Ted Ingling (GE Aviation’s GE9X program manager ) said the GE9x has unofficially beaten the GE-115B record thrust in cold weather triple red line conditions and stated a new record for the books will be forthcoming. That means at least 121% of rated thrust.. very impressive. But al...Jump to post
Once the grounding is lifted, Boeing might even deliver 200, 300, heck, maybe 500 aircraft in one month. But can we really call it a win, then? In the end, it shouldn't be much different than the last years, approximate total numbers for the two, with Airbus edging out the NBs (this year maybe more ...Jump to post
The briefest "hop across europe" I have ever done was LIS-MAD, it's barely a 1 hour flight and there's just no way in hell I would do it in on of those contraptions. Let alone anything longer than that. This is one of those things that needs to be killed by the regulators before it gains a...Jump to post
Thanks for that. What about a Titanium alloy? What are the pros and cons of that? Wasnt it used on the SR71 for structure and skin? Have the potential titanium alloys advanced since then? Is it suitable? Titanium has the strength of steel with half the weight. It can also tolerate very high tempera...Jump to post
Not sure there is one "very best". As mentioned, it's all a compromise. Even excluding cost, you have to consider weight, strength, repairability, safety, workability, etc... Among metals, you have magnesium alloys that are lighter than aluminum ones, but are also weaker and difficult to w...Jump to post
I am thinking, in this thought exercise, about a clean sheet design concept, where optimal cruise engines are supplemented by retractable thrust to be deployed when needed i.e at takeoff. That concept already exists as a possibility for future hybrid aircraft, were electric fans augment a cruise ga...Jump to post
drdisque wrote:Spirit didn't exist in 1982. It was founded in 1984 and didn't begin scheduled operations until 1990.
Well sure, when your longest route is 140km (75nmi) and you can land anywhere between and just sail the rest of the away, you can toy around with electric planes..Jump to post
Mr Sully only achieved his remarkable feat because he had an excellent copilot. It'd be polite to recognise that. Can you even name him without searching? First and foremost, he achieved that because he was in an Airbus A320 which comes with the flight envelope protection system. As per the NTSB re...Jump to post
It’s going to be embarrassing for the whole world when the accident cause is unrelated. It will not be embarrassing for anyone. There is circumstantial evidence that both crashes may have something in common and it may have something to do with the aircraft type.Even if the chance is only 1/1000 th...Jump to post
Given the two eerly similar accidents with massive loss of life of brand new aircrafts, particularly when the shady implementation of a new control system *might* be linked to them, I have little doubt that they are indeed considering a grounding. It's their job. Which isn't to say that they should ...Jump to post
The GE90's 127k lb figure was obtained during mandatory triple red line (maximum N1, N2 and EGT values) testing for certification. Source: https://www.geaviation.com/press-release/ge90-engine-family/ge90-sets-new-world-record-thrust-engine-completes-far-33 As for what the GE9X might do under the sam...Jump to post
Not very likely, IMHO. What would be the point of it, anyway? They already have the record, with the "bragging rights" that come with it. And that record came from normal testing, not from any intentional "record run". As for the GE9X, it targets a lower thrust point than the GE9...Jump to post
Aviation might be a "small" contributor to the problem (transportation represent about 15% of global greenhouse gases emissions, and aviation is just a part of that), but we are at a point where every single gram of CO2 counts. That fact that are bigger contributors is not an excuse to not...Jump to post
I always thought of the EJ200, Snecma M88 and F119/YF120 as good basis for engines to power hypothetical new supersonic transport aircraft. The first two for business jets and the latter for airliners.
All of them are relatively modern designs and conceived with supercruise in mind from the get go.
In a perfect system, you could accelerate a bit above the exhaust speed of an air breathing jet engine, do to the added mass of fuel to the total flow. ;) In practice, yeah, you need to accelerate the exhaust above the speed you want for the plane. And that's not going to happen with high bypass tur...Jump to post
and we were discussing why you couldn't hear the sonic boom for the launch (but you could hear it on reentry) and he said something to effect of the fact that after a certain altitude, you can't effectively hear a sonic boom. I'm no expert or anything, but might be that a big factor in not hearing ...Jump to post
I don't think a 96% load factor is something worth striving for. Calculations I've seen elsewhere suggests the sweet spot is around 85%. If your load factors are near 100%, you should increase the prices of tickets until it drops to around 85%. That's where you make the most money. Not sure that wo...Jump to post
Can't be absolute. In order to produce thrust, bypass flow must be accelerated above the vehicle speed. I would guess the delta starts big at take off and then gradually shrinks as the plane picks up speed. But never reaches zero. Core flow could produce thrust at absolute speeds equal or even a bit...Jump to post
GalaxyFlyer wrote:The only other geared fan engine, the TFE 731
Add a Vulcan second stage one day and there is nowhere in our Solar system it can't go. Vulcan is the Ariane engine, did you mean Raptor engine instead? He might be referring to the future Vulcan rocket, by ULA. I highly doubt that ULA would be willing to supply ACES upper stages to SpaceX, though....Jump to post
Watching the live stream of the post-launch news conference, Musk has confirmed that the core did indeed not land safely. As far as I could hear (the audio quality was a bit meh to start out with), it ran out of propellant and hit the water at 300 MPH I understood it run out not of propellant but o...Jump to post
I would add that a bit of an hard impact upon "landing" was far better than a possible much harder impact upon falling down after stalling, had not the flight envelope protection been in full effect.Jump to post
Perhaps it's a safety thing? So that passengers will be readily aware of any crew indications in an emergency situation?
Some airlines might think it makes a difference, and others not so much.
Just guessing, here...
*Or did I calculate something wrong? Entirely possible. I know engine efficiency is not in the calculations but it should be good enough to not cause problems. You did. Hint: 18650 cell can provide 80W of power for how many miliseconds? Many. I would appreciate if you could spend at least few secon...Jump to post