The "Real Aerospace" Thread

Discussion regarding the Outsider webcomic, science, technology and science fiction.

Moderator: Outsider Moderators

User avatar
Arioch
Site Admin
Posts: 4486
Joined: Sat Mar 05, 2011 4:19 am
Location: San Jose, CA
Contact:

Re: The "Real Aerospace" Thread

Post by Arioch »

RedDwarfIV wrote:I don't think that was VTOL? I remember him talking about how you could make a viable supersonic jet just by swapping out the Concorde's inefficient 60s engines for modern ones, and that going electric would let you fly above what is termed "coffin corner" (the point where wing lift and engine thrust meet due to lowering atmospheric pressure) because electric engines don't need air to operate
(aside from as a medium to push through).

User avatar
RedDwarfIV
Posts: 398
Joined: Sat Jan 25, 2014 12:22 am

Re: The "Real Aerospace" Thread

Post by RedDwarfIV »

Arioch wrote:
RedDwarfIV wrote:I don't think that was VTOL? I remember him talking about how you could make a viable supersonic jet just by swapping out the Concorde's inefficient 60s engines for modern ones, and that going electric would let you fly above what is termed "coffin corner" (the point where wing lift and engine thrust meet due to lowering atmospheric pressure) because electric engines don't need air to operate
(aside from as a medium to push through).
Cheers
If every cloud had a silver lining, there would be a lot more plane crashes.

Krulle
Posts: 1413
Joined: Wed May 20, 2015 9:14 am

Re: The "Real Aerospace" Thread

Post by Krulle »

Anyone here bought an AT-AT?
The Canadian Authorities issued a recall... :(
(link)

Yes, I kmow, May the fourth is over...
Vote for Outsider on TWC: Image
charred steppes, borders of territories: page 59,
jump-map of local stars: page 121, larger map in Loroi: page 118,
System view Leido Crossroads: page 123, after the battle page 195

User avatar
Arioch
Site Admin
Posts: 4486
Joined: Sat Mar 05, 2011 4:19 am
Location: San Jose, CA
Contact:

Re: The "Real Aerospace" Thread

Post by Arioch »

The ISS has its first comedy relief robot sidekick. The Japanese-made "Int-Ball" is an autonomous surveillance bot designed to move about the station and perform continuous inspections.



http://iss.jaxa.jp/en/kiboexp/news/1707 ... ll_en.html

Nemo
Posts: 277
Joined: Tue Apr 26, 2011 1:04 am

Re: The "Real Aerospace" Thread

Post by Nemo »

Arioch wrote:The biggest problem is of course limited range. It has a top speed in level flight of 300 km/h (186 mph) but a range of only 300 km (186 miles), which translates into a flight endurance of about an hour. Being stranded in an electric car without accessible recharge is one thing, but dropping out of the sky is another.

Complicating things here are the rules for fuel reserves.
§ 91.151 Fuel requirements for flight in VFR conditions.

(a) No person may begin a flight in an airplane under VFR conditions unless (considering wind and forecast weather conditions) there is enough fuel to fly to the first point of intended landing and, assuming normal cruising speed -

(1) During the day, to fly after that for at least 30 minutes; or

(2) At night, to fly after that for at least 45 minutes.

(b) No person may begin a flight in a rotorcraft under VFR conditions unless (considering wind and forecast weather conditions) there is enough fuel to fly to the first point of intended landing and, assuming normal cruising speed, to fly after that for at least 20 minutes.
So at night you have 15 minutes of travel time? Since its VTOL they may push for operating under rotor rules, but rotor craft are still stable with the engine off, which shocks people. Can't help but wonder what the glide slope looks like for it.

User avatar
RedDwarfIV
Posts: 398
Joined: Sat Jan 25, 2014 12:22 am

Re: The "Real Aerospace" Thread

Post by RedDwarfIV »

Just watched the video for that VTOL electric plane again. Is it just me, or did they choose a really inefficient setup for forward flight? The wing is right at the back, so the forward fans have to work to hold the nose up. Surely this would seriously affect flight time? Wouldn't the ideal plan be to have either forward canards to hold the nose up or to move the main wing forward?

Maybe that would add to wing weight if you wanted to keep the rear jets in the same position while still wing-mounted, but surely the advantage of a well balanced centre of lift would counter that better?
If every cloud had a silver lining, there would be a lot more plane crashes.

User avatar
Mjolnir
Posts: 452
Joined: Sat Mar 05, 2011 1:24 pm

Re: The "Real Aerospace" Thread

Post by Mjolnir »

RedDwarfIV wrote:Just watched the video for that VTOL electric plane again. Is it just me, or did they choose a really inefficient setup for forward flight? The wing is right at the back, so the forward fans have to work to hold the nose up. Surely this would seriously affect flight time? Wouldn't the ideal plan be to have either forward canards to hold the nose up or to move the main wing forward?

Maybe that would add to wing weight if you wanted to keep the rear jets in the same position while still wing-mounted, but surely the advantage of a well balanced centre of lift would counter that better?
The ducts of the front fans may be able to function similarly to canards.

Nemo
Posts: 277
Joined: Tue Apr 26, 2011 1:04 am

Re: The "Real Aerospace" Thread

Post by Nemo »

I was wondering about it, too. My hope was that they balanced it by using a lifting body with the heavy batteries in the rear pulling the center of mass aft. At speed maybe the body generates enough lift to compensate. Or maybe its just a tech demonstrator and they're just winging it. Its certainly not viable as is. No undercarriage, dreadful glide slope etc.

User avatar
Arioch
Site Admin
Posts: 4486
Joined: Sat Mar 05, 2011 4:19 am
Location: San Jose, CA
Contact:

Re: The "Real Aerospace" Thread

Post by Arioch »

I thought it looked unbalanced too, but I suspect that's the answer: the batteries are in the back. However, I still wonder about how it will compensate for widely varying loads.

Jayngfet
Posts: 55
Joined: Sun Jul 02, 2017 4:22 am

Re: The "Real Aerospace" Thread

Post by Jayngfet »

To loop back to the A-10 discussion, you guys are all a little bit behind the curve. If the A-10 was hated before it's probably a bit less now. That is to say, that the people who actually flew them are now the ones making the decisions. Congresswoman McSally being the most obvious example since that's the craft she made her air force career piloting and she's since been fighting tooth and nail to keep them flying.

I highly doubt they'll take many radical adjustments, but obviously the news since that thread of the discussion has made it clear that the hate for the craft is a bit overblown in the discussion. Though I think that's as much due to the current administrations love-hate relationship with the F-35 as it is whatever virtues and fans the A-10 has inside of it.

Nemo
Posts: 277
Joined: Tue Apr 26, 2011 1:04 am

Re: The "Real Aerospace" Thread

Post by Nemo »

The F-35 is an abomination that should have died more than 10 years ago. That aside.

The best fix (that will never happen) is the Air Force needs to go away as a discrete armed service. It was created at a time when the talking heads thought atomic war was the future, and the bomber fleet would make armies and navies obsolete. Fold it back into the Army Air Corps and refocus it on ground support, maybe then we can get enough AC-130s and A-10s (or their equivalent replacements) to do the job.

Jayngfet
Posts: 55
Joined: Sun Jul 02, 2017 4:22 am

Re: The "Real Aerospace" Thread

Post by Jayngfet »

The problem is designing a good replacement in this political climate. While the current administration is bellyaching over costs they sure as hell won't fund another design.

Nemo
Posts: 277
Joined: Tue Apr 26, 2011 1:04 am

Re: The "Real Aerospace" Thread

Post by Nemo »

Well, the first question is going to be, "Why do we need a new plane?". Why spend money letting the DoD build another boondoggle?


Every admin should belly ache over costs. That's how Truman came to be President, after all. Belly aching over costs in the middle of a world war.

discord
Posts: 629
Joined: Thu Mar 24, 2011 7:44 am
Location: Umeå, Sweden

Re: The "Real Aerospace" Thread

Post by discord »

the plane the US military needs is a cold hard look at the F-16 and see how can we make this better while retaining ease of use and maintenance, then mass produce the shit out of it again, so the military actually can have enough flipping planes to be all the places it needs to be at the same time.

best plane ever? no, silver bullet? not even close but cheap(which is a silly term when applied to jet fighters, but still true) enough to get ENOUGH of the damned things.
or they could simply buy the JAS-39 Griffin from sweden, it pretty much fits the bill, with the possible exception of it being a bit short legged.

for the A-10 replacement, i would actually look at a relatively lightweight turboprop, rough field usage, ease of maintenance, multipurpose(to get rid of some specialization) and keep the flipping price down would be the points to put effort into.

User avatar
icekatze
Posts: 1399
Joined: Sat Mar 05, 2011 8:35 pm
Location: Middle of Nowhere
Contact:

Re: The "Real Aerospace" Thread

Post by icekatze »

hi hi

When you're in the middle of a real war, you actually need to be concerned about opportunity costs of things, if you want to win. When you're not in the middle of a real war, you can focus on the task of making you and your business partners as rich as possible instead.

dex drako
Posts: 64
Joined: Mon Mar 21, 2011 4:37 pm

Re: The "Real Aerospace" Thread

Post by dex drako »

lets be honest here people any real war would mean the end of humanity as even just 5 nukes could send the world into a "nuclear Autumn" and likely cause the end of humanity. the only wars left are the "play wars" we fight in third world countries that can't really fight back so defense contractors can milk their sponsor country for ever dime they can.

no one cares how bad the f 35 is because it was never meant to really fight a war.

Nemo
Posts: 277
Joined: Tue Apr 26, 2011 1:04 am

Re: The "Real Aerospace" Thread

Post by Nemo »

I wouldnt put much faith into the nuclear winter type scenarios. They were based on flawed computer models that never properly accounted for precipitation, among other things, and were produced by people who had a vested interest in an outcome. The people who put it together wanted to scare the world into pressuring the leadership away from nuclear war. 5 Separate nukes would start 5 separate large wild fires and spread some localized heavy metals and radiation. Nasty if you live there but not world ending. Hell, we can't even point to changes in climate records from Mt Pinatubo or Mt St Helens, and by rights there should be according to the models. Generally, the soot doesn't behave in the models as it does in reality. Beware the scientific and technological elite holding public policy captive. It was Eisenhower's next line after warning about the industrial-military complex.

When you're in the middle of a real war, you actually need to be concerned about opportunity costs of things, if you want to win. When you're not in the middle of a real war, you can focus on the task of making you and your business partners as rich as possible instead.
Mmm. Not the problem, I think. The problem is the speed of war. In the past you could let war come and mobilize afterwards in response. With today's weapons you can knock out the opponent's industrial potential within hours. As a result, you have to mobilize for war during peace while the conflict itself remains theoretical. So you dream up an imposing problem and the means to over come that. To do less would be dereliction. So they produce the "best" weapon systems, like Tigers or Panthers as opposed to Panzer 4's and Stugs. Wait! Those were made during the war! Yup, same mentality can strike in peace or war. Its not about lining the pockets of the business partners during peace, is the point.

People tend to narrow a problem's scope to make it manageable. In these problems, people narrow weapons of "war" into weapons of "engagement". Given the speed of warfare, one decisive stroke at the onset is enough to win - so win that first battle. But like discord said, we just dont have enough of these wonder weapons to station everywhere they need to be. Again, I want to point out that roughly the same total of money would be spent buying hundreds of cheaper weapons or a few dozen of the Congress approved F-35. Its not about the money (solely or mainly), its about the method. And right now, its madness.

User avatar
icekatze
Posts: 1399
Joined: Sat Mar 05, 2011 8:35 pm
Location: Middle of Nowhere
Contact:

Re: The "Real Aerospace" Thread

Post by icekatze »

hi hi

Actually, we can point to climate changes from Mt. Pinatubo. We have a lot of good data on it. The year afterward saw a .5 to .7ºC cooling effect, and it also created a massive opening in the ozone layer around the event. We can also look a the rather famous "Year Without Summer," in 1816, caused in large part by the eruption of Mt. Tambora.

While there weren't any papers published on the topic of nuclear winter from the 80s to the mid 2000s, since people didn't think it was very likely to happen at the time, people are starting to take it seriously again. Recent papers with more up to date models still show a strong case for nuclear winter following a nuclear exchange. Multidecadal global cooling and unprecedented ozone loss following regional nuclear conflict

It may be a good idea to beware the scientific and technological elite, if one is unable to understand the science. It can be hard to separate the legitimate from the quackery, and a healthy dose of skepticism is good for anyone. But at its heart, science does not require an appeal to authority to validate itself, it can stand on its own merits. People can ignore the science at their own risk.

----

Also, I suspect that if General Dynamics spent hundreds of thousands of dollars on politicians and key army personnel so that we could build thousands of tanks that do nothing but collect dust in the middle of the desert, in the middle of a war, there would be accusations of war profiteering. Instead these kinds of things, that actually happen now, are considered politics as usual.

On the other side of the coin, you can look at the case of German flak artillery in WW2. The central authorities wanted lots and lots of flak, even though it was only marginally effective at shooting down allied bombers. They ignored the advice of their generals who realized that the opportunity cost of producing massive quantities of radio proximity fuses for flak shells was leading to a serious shortage of radio equipment on the eastern front.

When you're not in the middle of a war, you can take huge campaign contributions and say, "Well, we don't want to gamble on national security, do we? We'd be fools NOT to throw a bunch of money at this." And not see immediate drawbacks.

Nemo
Posts: 277
Joined: Tue Apr 26, 2011 1:04 am

Re: The "Real Aerospace" Thread

Post by Nemo »

I suspect if GD built thousands of tanks that sat in a desert during a war, Congress would be calling in SecDef and JCS to question why they aren't at the front. Not GD.




Well lets check things in a bit more detail. Science is all about predicting the future, not explaining the past.

https://pubs.giss.nasa.gov/docs/1992/19 ... 00800v.pdf
SpoilerShow
Image
Looking at Hansen's paper predicting the effects of the eruption they indicate a change in temperature of ~0.6 Celsius, a three sigma event which should happen only once in a thousand years.
SpoilerShow
Image
Image
Oh dear, I seem to have cut off the years on the graph! Can someone help me, I seem to have misplaced my volcano? Where was it... point it out if you see it. (The two graphs feature a dissimilar X-axis, not my doing!) More seriously, according to Gistemp we saw a slight drop of about ~0.2 during the time frame in question, which matches up with numerous other temperature fluctuations and is within margins of error for instrumentation and variability.




https://www.atmos-chem-phys.net/4/1217/ ... 7-2004.pdf

Looks at incoming wm² and albedo. Total energy has an observed affect at around 2 wm² in the outgoing shortwave band for a period after the eruption, which is also coupled to an El Nino event. Combined, they still dont overwhelm other observed variances in OSR, despite the fact that the observed effect reaches as high as 10 wm² at the target mid latitudes.
SpoilerShow
Image
SpoilerShow
Image
Curiously, the paper also notes there are unexplained (ie not modeled) variances in observations during the mission. The short of it, unaccounted for changes in cloud cover in the tropics. Note this the mission extends well past just Pinatubo - just a nice oddity to bring up on a tangent.



I'm going to have to spend some time dissecting this latest paper on nuclear boogeymen, but on a skim reading they're hyping the damage as the "lowest temperatures in a 1,000 years"! Citation Mann et al., 1999. Heh. Every piece of their math could be right, but they're still going to hobble themselves by overstating their results attaching it to a manufactured outcome paper. Why? Because of the intent. The demanded mantra and Truth™. So initial impression is not favorable, but I'll try to set that to the side.

User avatar
icekatze
Posts: 1399
Joined: Sat Mar 05, 2011 8:35 pm
Location: Middle of Nowhere
Contact:

Re: The "Real Aerospace" Thread

Post by icekatze »

hi hi
The global mean OSR anomaly shows great variations reaching values of 4 Wm^-2, above or below the 14-year mean value. During the 1991–1992 period, a large increase in the reflected OSR flux is found, which can be attributed to Mount-Pinatubo eruption in 1991.
- Long-term global distribution of Earth's shortwave radiation budget at the top of the atmosphere, N. Hatzaianastassiou, et al.

Looking at both of the papers linked, they both indicate a noticed change, not the lack of a noticed change. The fact that Pinatubo happened during an El Nino event, and still produced a noticed cooling effect is noteworthy, because El Nino tends to create a contrary warming effect.

Also, it is my understanding that top of the atmosphere shortwave radiation data gathered from satellites, cannot by itself, provide an accurate measurement of surface budgets without the addition of cloud optical thickness inputs from separate sources.

Post Reply