NoClass

We should all probably stop and take note of Ferram's awesome explainer, above. From it, one can not only learn a bit about aerodynamics, but also how to teach aerodynamics. No easy feat.

Interesting... I've been running experiments too, because there's an irritating lack of documentation on how science is supposed to work... Still, I haven't noticed any difference in recovery yield through EVA activation. Specifically, I'm getting 5.4 science for recovering a Seismic Accelerometer mounted to a MK2 can on the launch pad. This is true if Bob (lvl 2 sci) is in the can or on EVA. So your results are curious to me. How exactly are you activating "manually" on EVA? I'm assuming that means that you are controlling the scientist on EVA, getting close to the experiment module, then right clicking to perform the experiment. The only difference the scientist seems to make for me is on the transmission efficiency, which turns to "basic analysis" (in yellow), regardless if the scientist activates manually or is in the can. (Though there is supposed to be a bonus, I get 2.4 regardless. That might be a rounding issue). This is in contrast to what the wiki currently says, that scientists give a bonus to "recovery". It's clearly a bonus to transmission, just like in the Beta. Interestingly enough, I've noticed that the "basic analysis" bonus stays even after the scientist has left the craft and walked away. Using brackets [ ] to switch between craft doesn't seem to reset this bonus, but switching to the space center does reset the bonus. I assume that switching to a distant craft on the map will reset it as well. Experiments collected by non-scientists on EVA don't show the "basic analysis" bonus, even if they're added to a craft with a scientist on board. It would be great if there was some sort of authority out there on how this is supposed to work.

It would be nice to have, allowing slightly easier takeoffs for heavier planes, but I figure if ferram hasn't added it to FAR yet, then it's more complicated than it seems.

Doesn't ground effect have a huge impact for takeoffs and landings for all craft?

Interesting stuff! Do you know the mass of your plane during the level flight test? ...maybe a value for wing loading?

Because the aero model in 1.0 was radically simpler and less realistic. Most parts had a very simple drag model based on their mass, which made it much easier to control a rocket that wasn't pointed into the relative windline. *edit* ninja'd

My understanding is that it's also generally close to where you have maximum L/D, which is related to both a particular speed and AOA. (I use an AOA, because it shouldn't vary with altitude) ...but I don't know how much your actual thrust angle affects best rate of climb if you have high TWR. What I'd love to predict is best range speeds/altitudes for craft while constructing.

Regarding wingtip winglets Whoah?! Really? That's awesome! I guess I have no freaking clue how FAR actually figures out induced drag. Any chance you could explain that? (not actual induced drag, but FARs method)

Hrmm, how would this help with vertical symmetry? Actually, here's a deeper question: Are we sure that the control surfaces are actually misaligned? There may be a difference between where a part is drawn on the screen, and where it is calculated to be for the sake of game physics. Also, if you play around with it, you'll notice that the round pieces of the control surfaces are perfectly aligned. I don't know if this is significant. Mysteries!

Here goes. I thought at first that it might be a clipping problem. You'll notice that wings in tetryds's post are overlapping slightly, despite the fact that they were placed on a centerline using symmetry. It's funny, because I noticed that in recent KSP versions, it can be hard to get a bilaterally placed part to appear. You kinda have to massage it into position for the part to pop up on the other side. Anyway, to eliminate clipping, I simply moved the wing down the side of the tank. Delta Wings Placed Bilaterally near the top of a tank, with Small CS, Hosted by imgur.com ...same problem. So I did as asked, individually placing wings on top, and wings slightly lower. Swept Wings Placed Individually on the Top of a tank, with Small CS, Hosted by imgur.com Swept Wings Placed Individually near the Top of a Tank, with Small CS,Hosted by imgur.com I also tried bilaterally placing the wings, but individually placing the Small CSs, but to no avail. I'll spare you the pics. You'll also notice that I used both delta wings and swept wings. They all seem to just be flipped, and are not symmetrical in the horizontal plane. *sigh* This is making me OCD.

That's... interesting! The only input I have is something I read (can't remember where) about how SAS torque is applied in the KSP engine. That is, SAS torque is applied directly to the center of mass of the craft, rather than on the actual torque part. So, SAS parts on the wobbly section wont stabilize it unless the CoM is in the wobbly section. I'm curious about how SAS works WRT control surfaces, RCS, and gimbals on craft that can flex. Does SAS recognize when the control part has been moved relative to the CoM, and adjust input accordingly? Or do control parts move based on where they are in the craft file?

Here's a technique I used, though it's from an old craft I no longer have (so no pics , words must suffice.) Basically, pick one of the craft and build a spacer part that fits snugly onto both docking ports in the assembly building. This part doesn't have to be fancy (and it will never fly), it's just a few structural components and docking ports that line up with the craft. If you save this part to a subassembly, you can then mount it to your other craft, and it will show you exactly where to put your ports on that other craft. FYI, it's really hard to get these things perfectly. Allow for a little bit of flex in your craft, and expect to be slightly off balance in flight.

Y'all correct me if I'm wrong. In the VAB, the windline for CoL calculation purposes assumes that air flow is coming from the open door, rather than the roof (which is the way most rockets would be pointed). To get an accurate CoL using FAR, one must rotate a rocket to point out the door. Also the vector arrow on the "CoL" indicator doesn't appear to mean anything. (y'all can add me to the list of people who prefer the use of "Aerodynamic Center" to "Center of Lift")

I've been able to get the BACCs boosters to properly separate with a couple of seperatrons mounted to the top of each. That never used to be necessary, of course, but it functions as a workaround.

That's some good info! I had a long winded post explaining that the problem isn't so much with glide ratio, which seems right on, but that craft seem to hold onto their energy for waaay too long. In that video, our brave Viper driver flares about 10 seconds before touchdown, and kills about 75 kts of speed in that frame of time. (~ 215 to 150 kts, or ~105 to 75 m/s). I couldn't get even wide-winged planes to slow down that fast. ...then I dumped fuel (TAC fuel balancer). That's the missing piece. KSP parts tend to be a bit more dense than in the real world to begin with, so an aircraft full of gas will take a lot longer to slow down to max glide speed. TL,DR; Dumping a couple of tons of gas will radically change how quickly your craft slows.

Honestly, I've had the same "feel" as well when playing with FAR. Specifically, that something is off in the way drag is handled at relatively low speeds and high AoA. It "feels" like aircraft take a very long time to slow down to glide speeds after the engine is cut, even with spoilers and speed brakes. I won't tell you our feelings are wrong (Ferram will tell you that, though. He's a true engineer!), but I can posit some reasons why our feelings are wrong: -We're not used to aircraft designed for low drag and high TWRs. Many real world aircraft don't fly more than 1.5-3 times faster than their stall speeds, so an aircraft aerodynamically designed for high-speed/low-drag may indeed take a long time to get down to a slow flight regime. Does anyone know how long it takes an F-16 to get down to stall speed after cutting the engine in level flight? -The glide ratios and stall speeds of aircraft designed in FAR/KSP seem normal (at least to me, and I think you agree). This is hardly proof, but it would be very hard for FAR to be right about all the L/D derived slow flight numbers, but wrong about how low speed drag works in general. -I've noticed that bad installs of FAR after a KSP change can magnify this "feel." Everything will look to be normal, but some part of the drag model is missing because I am careless with my zips, and I do indeed have infinite gliders. Deleting and re-installing everything has solved 99% of the weirdness I've ever seen with this mod. ...or maybe the low speed drag model actually is a little off

dang, NINJA!

I recommend NOT worrying about the graphs at this point. There are a few numbers in there which can be helpful to all, but in general it's too much data for someone working on the basics.

Ahh, that's right! I remember doing the math on this once and being surprised. I'm too lazy to do it again though. How did you come to this conclusion?

I suspect that English is not his first language.

Honestly, half price for an item recovered from space seems like a good deal. I may make this change myself. Well done answering your own question BTW.

RoboRay has the best answer above, but I'd like to expand on one thing... Speaking precisely, a rear CoL will not by itself pitch the craft downward. All it will do is pull the tail out of the windline, away from the direction of flight. If there was no gravity then the aircraft would continue to point in the same direction. However, if you're not producing lift, gravity will begin to pull the direction of flight downward, the angle of the airflow will point downward, and your stable craft will follow. Aircraft that are nothing but tail (like an arrow or a fin-stabilized rocket) will follow a nice ballistic curve, with the nose pointed in the direction of flight (which curves) the whole time. But, if you have wings that produce lift, and hold the nose slightly above the direction of flight, you'll keep flying forward.

You must ask yourself, "Jetsim, where does the air flow?" In flight, the CoL will always pull the tail of the plane away from the flow of air, and move behind the CoM. If you were flying backwards, the air would be moving back to front, then the CoL would flip the plane backwards. Don't fly backwards!

According to the J58 page on Wikipedia (blessed be the Font of All Knowledge) it's similar, but the KSP turbojet is still about 150% more powerful for its weight. The J58 is a 2700 kg engine thrusting 150kN wet and 110 dry. Of course KSP crams all the mass into a small exhaust section and calls that the "engine." I didn't read too much into the page, as it's late and I have a short attention span, but I didn't see anything about fuel flow, which I suspect is much higher at full 'burner than KSP. I also suspect the thrusts at various airspeeds are radically different (especially for low a/s). As an aside, props to Alshain for patient and respectful explanation of the basics.

I'll have to look at Kerbal Engineer. IIRC, it has a bit bigger UI footprint than I'd like, but it's far better than manually adding up the mass of each part! Thanks for the answers folks.