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Evan
Evan
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Last Activity: Today, 12:53
Joined: 2008-01-19
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  • You forgot the word "down"....
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  • The video skims over the finer details. The A330 ADIRU actually had error detection to protect against cosmic interference but the nature of the sampling interval left a small window of vulnerability. That was designed out after the investigation and it hasn't recurred since.
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  • Cosmic Particles, Bit Flips and Qantas Flt. 72

    This video explains the phenomenon of binary bit flips caused by cosmic particle radiation. I recommend watching it from the beginning.

    This is the part that explains the upset events of 2008:

    https://youtu.be/AaZ_RSt0KP8?t=877
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  • Fun fact: the inventor who first advocated for adding lead to gasoline was so sure of it being harmless that he ingested lead to prove it. After some time he became so crippled that he devised a system of ropes and pullies to help him get out of bed, which he then because caught in and it strangled him....
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  • They also don't catch on fire explosively in any case. On the downside, once they catch on fire, they are very difficult to extinguish. This is one of my major concerns with placing large lithium batteries on airplanes....
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  • I've had this image from way back, so I don't remember the exact details, but I think it used liquid sodium along with helium and possibly some added closed-circuit water cooling. It heated air and sent it to the turbines and used return air for cooling as well. It was a retrofit for the B-52 or the B-36. It definitely left some radiation in its wake....
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  • I got that. It's the half-life of fission products that makes it very problematic. But, yes, continuing to burn carbon fuel will be more directly devastating. Fusion will come to our rescue eventually, but maybe not soon enough.

    Behold, the nuclear aircraft engine:

    ...
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  • The main problem with fission is that it produces toxic radioactive waste that will remain toxic for far longer than any containment system we can foresee. So, unless we shoot it into deep space, we are just making time bombs.

    Did you know that nuclear powered aircraft were once actually a thing? Definitely not a good thing....
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  • I'm pretty much of the same mindset. There are a lot of places where electrical power can easily replace fossil fuel (assuming it comes from renewable sources) but, for the reasons you just stated, aviation isn't one of them. If we could move much of the world's terrestrial power to renewables, it's possible that we could continue to burn JET-A and still avoid climate disaster. But let's assume that we aren't going to do that, because industry probably isn't going to do that.

    I take it you are referring to synthetic fuels that use hydrogen to extract CO2 from the atmosphere. To begin with, this is only a carbon neutral solution. It won't help the world from exceeding the 2 degree warming threshold. And it's only a carbon neutral solution if the hydrogen is produced with renewable energy. Scale this up to the needs of global aviation and I doubt this is going to be the case. Of course, the same thing can be said about electrical generation for battery power.

    To...
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  • Well, I hate to break it to you but......
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  • Apparently, well-made, undamaged batteries do not burst into flames any more than well-made, undamaged fuel tanks do.

    Airbus is exploring the hybrid route now with their E-Fan X research aircraft. This is testing a 2700hp electric motor in the #3 position of a BAe 146, with electric generation powered by an AE2100 turboshaft similar to the ones used on the C130J. Obviously, getting 2700 electric hp from a 4600hp turboshaft isn't what you could call efficiency but the point of this endeavor is to develop technology, not efficiency. However, they also install a 4400lb battery providing 2MW which equates to the same 2,700hp. The trick is to lose the hybrid aspect, the turboshaft. I suspect the work being done now anticipates further breakthroughs in battery and motor tech that will one day result in a battery 'fuel weight' needed to match turbofan ranges. There are other challenges, such as thermal issues (cryogenics may play a role) and high altitude corona effects (pressurization...
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  • Deeps thoughts about electric airliners

    With electric-powered airliners possibly appearing on the distant horizon, I got to thinking... Safety dictates that you would need to depart with enough battery charge to meet the same requirements that apply to fuel orders... ramp battery, taxi battery, trip battery, contigency battery, battery to alternate, holding battery, etc. But there are important differences. For one thing, the 'fuel' weight is fixed and constant, so it doesn't factor in determining available payload or optimal flight level changes. Since the weight is constant, the 'burn' is constant. But what about redundancy? I assume these designs will have multiple batteries with multiple cells. If you lose a cell or entire battery mid-flight, that has to be fail-operational, so you would need additional battery units as backups that are not included in the 'fuel' order. Perhaps you could retain the APU with a generator for emergencies, but then you would need to provide a fuel tank for that and would probably never use it....
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  • Well, it seems that I assumed wrong. The deviation occurred on ascent, the climb was shallower than planned, and the issue was that they might therefore not be able to glide back to their "spaceport". And I guess you don't want some billionaire landing his "spaceplane" on the interstate or on someone's trailer home. Anyway, the FAA has grounded them, so they must be bored too....
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  • As ever....
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  • Ban all billionaire space planes?

    The FAA is investigating an unintentional flight plan departure that occurred during the recent Virgin Galactic flight carrying Richard Branson. The flight reportedly dropped below the altitude it was approved to fly at for one minute and 41 seconds. I assume we are talking about an altitude shared by conventional aircraft and that this is a RVSM issue. The crew seemed to have rectified the problem without much drama. Still, RVSM was made possible by a standard of reliability in autoflight height-keeping technology, so those ultra-luxury Space Rovers need to be held to this standard or stay out of RVSM. Cuz, it's gonna get crowded up there with all these billionaires about.

    https://edition.cnn.com/2021/09/02/t...scn/index.html

    Or maybe... ban all billionaires...
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  • All done with an FAA-approved time in service interval extension I assume. Or maybe that's why you have four engines on board. Anyway, kudos to United for playing it safe....
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  • Yes, except that you call it 'quite disappointing' and I call it 'tripe'....
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  • Yes, clearly all that metal is attracting too much lightning. Ban all metal!

    BTW, I saw today that Atlas will be involved in the Afghan evac operations, transporting self-loading frieght for a change (though not from Afghanistan). Part of the Civil Reserve Air Fleet....
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  • Agreed but that's not the bottom line here. Absolutely yes, anything that provides greater SA could have helped. Is that his claim? No.

    He entices us from the get go with a statement about how the automation was at fault, thus inplying that the design is somehow unsafe. Typical populist nonsense.

    If Airbus ditched their FBW and moved back to control columns it would make the design safer for certain ultra-rare scenarios brought on by the failure of CRM and cockpit gospel rules. It would also make it less safe in many other ways. It Boeing ditched their control columns for sidesticks and hard envelope protections, the same is true in reverse. What's the point? Neither are unsafe! Neither have ever caused a crash.

    Maximus is just trolling the know-nothing population with shock 'journalism' in a mad grasp for attention and the revenue it brings him. Why are we even discussing this tripe?...
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  • Is it? If the aircraft is in a nose-high attitude, which the PNF can see clearly by the PFD, is it really necessary to feel the other pilot's commands? Obviously, they are nose-up commands. The thrust setting is visible to both pilots. How can the monitoring pilot not recognize what the flying pilot is doing at that point? And, in the event of dual input, is the problem a design problem or a CRM breakdown/absence problem? If it's not 'your airplane' you don't make control inputs, period. I call bullshit. This was a human error and training deficiency accident and here comes the little dot....
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