Comments by "Mikko Rantalainen" (@MikkoRantalainen) on "Real Engineering" channel.

As far as I know, MCAS wasn't needed because engine cowling were higher. It was needed because the engines needed to be moved forward which caused engine power to forcefully push the nose of the plane upwards whenever the engine power was increased. Similarly, the nose of the plane would drop rapidly in case of engine failure or rapid throttle movement.
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@phoenix042x7 I think Germany is just accepting that they will lose about half the potential energy that PV panels could generate. That is getting fixed simply by installing double the amount of panels per MW and with cheap enough panels it may actually work. However, I think the max power consumption is during the winter in Germany, too, and the PV panel output is the lowest at the same time so this cannot be all-around solution for Germany until somebody comes up with a good plan to store lots of energy for half a year time periods. Synthetic fuels is one way to do that but the efficiency of electricity -> synthetic fuel -> electricity is about 10% so if you go with than plan you lose 90% of all the energy you actually collected.
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Great video! And the storytelling was great, too; there were countless of moments where I felt "Oh, there's even more complexity after everything that was explained this far". Overall, the documentary was easy to follow even though the subject matter is definitely complex.
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Great video! I learned a lot of small details about F-35 and the most interesting for me was the gradient tape.
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Yeah, the solar irradiation maps often don't bother including Scandinavia in the map at all because PV doesn't make much sense up here North. It doesn't seem to prevent PV panel dealers from trying to sell full installations, though. (PV panel setups are usually designed for 1000 W/m² radiation and you can get maybe 300 W/m² on average here in Scandinavia and the output is heavily tilted for the summertime only – if the panels were cheap enough you could just triple the basic installation sizes but it currently doesn't make much sense right. In addition, the most yearly output from those PV cells happens at the same yearly period when we need the least energy! During the peak electricity usage in the middle of the winter PV panel output is approximately 0%. Of course, you could generate synthetic fuels from the electricity during the summer time but the efficiency of that process is about 30% so you get to triple the PV panel setup once more. So to make PV panels worthwhile here in Scandinavia the prices would need to drop at least 90% compared to current best performance/cost panels. I think it will happen in the future but we're not there yet. And that's for the best case situation where you can store hydrogen from summer to winter and use fuel cells to generated electricity. If you generate e.g. synthetic methanol or gasoline you're going to lose another ~70% of the output if you want electricity out during the winter. So you would need to triple the installation yet another time. The energy storage with reasonable efficiency for half a year is still unsolved problem. If you're willing to lose about 90% of the energy in the process, it's doable already.)
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You seem to be missing just how hard it is today to make a good hydrogen tank. With our currently available technology, spare hydrogen tank is not going to happen. In addition, hydrogen has such a tiny molecules that leaking through the wall of the tank is a real problem. You simply cannot make a portable tank that you fill once and throw in your trunk for future comsuption in case your main tank gets empty. See https://en.wikipedia.org/wiki/Hydrogen_storage for extra details. Notice, for example, that pure liquid hydrogen has less hydrogen per volume than gasoline!
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@stringpicker5468 Boeing couldn't use 2 sensors because FAA considers any redundant system as critical and you cannot use the same type certification with additional critical systems. That was the incentive for Boeing to use only one sensor. Boeing offered second sensor as an option but that couldn't be used as automatic fallback either or FAA could have considered that system as redundant, too. I think it was marketed as reduced downtime in case of sensor failure (because you could fly the next flight with another sensor if one failed).
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@roowut Try watching video titled "Boeing 737 Stall Escape manoeuvre, why MAX needs MCAS!!" by Mentour Pilot (an actual Boeing pilot that trains new pilots) around 16 minutes mark for a better explanation.
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@MatthewOstergren The problem with current PV panel technology is that you would also need to keep the panels as cool as possible. Without that requirement, it would be easy to build a huge array of panels in e.g. Sahara desert where you have no lack of sunlight. You also need a method to keep the panels clean because even 10% shading will cause huge output losses with current technology. In many cases even 5% partial panel shading may drop the power output by 30% or more. And the easiest way to keep the panels clean is to wash them with clean water. And that's one resource which is not available in Sahara.
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For more details, see this fine video from 1973: https://youtu.be/uG35D_euM-0
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@ReflectedMiles So, are you arguing on ad hominem or his actual merits?
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@ReflectedMiles I agree with lots of what you said here. To me, it appears that he is a lot more interested in psychological side and mechanical details of aviation than most pilots. I'd guess he has a better understanding of minute details of many major incidents than even more experienced (in type rating count or flying hours) which would definitely given him an edge in situation where you would need to quickly understand what's happening in case of malfunction. That said, he seems to make mistakes, too, so you shouldn't take everything he says as gospel either.
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