Leonim

Not exactly, a 100kN engine would indeed provide its full thrust power in vertical orientation, but it will only translate to 50kN in lift power. I should have been more accurate in my phrasing. It can be checked with the Builder Helper (section "Atmospheric Flight Engineer": Max Thrust, Low and High Altitude Lift), and experienced with a simple build. Note that using a gyroscope to change the orientation of the contruct is modifying this behaviour coherently. Still, atmospheric engines to my experience (at least with no more than basic pilot skills) still provide half their power as lift (along the gravity vector). --- Thank you Pinneman for doing that test, but it can still be interpreted as your engines using 83% of their power (80kN) to provide those 33,2kN of lift. To my comprehension, if your ship mass would have been above 4 600kg, your ship would not have been able to stay stationary and would slowly descend. With a mass of lets say 6t, that setup (vertical atmospheric engines) should not be able to even lift above what your ground engines have as height range, no matter the orientation, only wasting fuel in the futile process (and quite a lot at that, since trying at full power). --- Sadly, the default autoconf controls don't use subtags priorities to enforce the use of "ground"-tagged engines before adding the "not-ground" ones to the mix. Since the job is distributed evenly to all lift-capable engines, hovering cost way more fuel than it should if your setup has some vertical engines. Just a reminder but hover engines are way more fuel-effective than atmo engines, by at least a factor of 50 for the worse of them, so better tweak those controllers in such cases. On a side note, the Hornet in the Air Challenge mission can be effectively used for the final deliver on the flying fortress after using the Freelancer (linked container) to hover and gather everything below, but with neither a gyro's axis swap nor auto-level features, it is still safe but unwieldly to lift/land vertically (easier to brake/crash landing in a hurry, yet nice training for vertical maneuvers). Back on track, somewhat, an "Hover Engine S" can provide 50kN of max lift, same as the least powerful airfoil, the "Compact Aileron XS": atmospheric constructs are indeed meant to fly like planes. Though if you want to be fuel effective, thanks to adjustors, they can copter at very low altitudes (using only hover engines to move around). And even glide (only airfoils) if you build them right, though without aerial currents, its quite the challenge to regain potential energy, still very useful for feather landings.

Max Lift is possible as soon as you pass the sustentation limit for your construct's weight, depending on the current gravity and thus altitude (for an estimation, in build mode, check the building helper / atmospheric flight engineer / high altitude lift). To simplify, you can potentially reach max lift as soon as you have at least 1g of thrust. Anyway, the default in-game Flight System only use that potential lift to counter the gravity force and air friction for your given throttle (or cruise speed), unless you hit the spacebar for full lift using all the construct's vertical capabilities. If for one reason or another (too much angle, loss of power, less atmosphere, higher cross-section) you don't have enough lift, you fall, simple as that. If I remember correctly, during early Beta, the Lift Power in kN (kilo-Newtons) was the required power to fly 1t (ton) at 125m/s on Alioth (with a gravity around 9.8, not taking air resistance into account). Since I have some downtime, you're in for a long post, quite a rarity for me nowadays. --- Yet with simplified aerodynamics, your Current Lift mainly depends on your Angle of Attack (the ship's orientation compared to the "horizontal" plane: generally pitch is what matters if you are level, plus roll and yaw as well when not properly aligned). Ailerons, Stabilizers and Wings have different preferences before they reach their specific stall angles, which are way higher than in our non-futuristic real world, but may still be a worry. Note that your current lift is not that much affected by the ship orientation but you must stay aware of the basics: "root(cos(AoA))" act as a multiplier. For instance an AoA of 20° "only" provides 97% of your lift, while its reduced to 84% for 45° but then you are close to Stalling anyway (and already have with ailerons). Beware that pitching, rolling and turning at the same time causes cumulative dampening of your lift power... and sooner stalls. To avoid further stalling, and a potential Death spiral dreaded by any pilot, the easiest way in-game is to align your ship back with your current velocity's vector to regain control (use the X shortcut to visualize that trajectory)... as long as you have enough altitude for that maneuver. Since every construct is built differently with a mix of Airfoils, the AoA to achieve Max Lift may vary, but less than in real-life since all in-game forces are applied from/to the construct's center of mass (visible in the builder helper) and the angles are so far the same within an airfoil category. If you are mainly using wings, you are fine up to a whooping angle of 50°. Ailerons have closer specs to IRL wings, which means they stall earlier, above 30°, but help with fine adjusting the torque (by +/- 5°). Finally, stabilizers were not meant to be used as horizontal airfoils, but don't stall until 70°. As a guideline for ascending the fastest, aim for half those values for the Sweet Spot between improving the sustentation power and reducing the lift-induced drag (air friction). You can check the wikipedia article on "Lift-to-drag ratio" ratio for more information and the why. Too much angle and you'll lose too much speed due to air friction, even if your airfoils are not yet stalled. For the sake of information, the Lift/Drag ratio (shown in item inspection) should tell you how aerodynamic is an airfoil. It also hints about which angle would be best suited to land horizontally with, mainly irrevelant since we use omni-directional brakes and hovers (and/or vertical boosters) to achieve vertical landings and takeoffs (VTOL). What affects your overall atmospheric speed the most are Cross-section Surfaces: the frontal one define the construct's current air resistance/friction (the drag, which is the other force going against your atmospheric flight), the horizontal ones is supposed to help you with lift, and the vertical one against drift. Again simplified maths, since as far as I know, the only time when the "real" cross-section (facing your current trajectory) is used is for damage checks during Atmospheric Reentry, so aim wisely: like you would dive in water. Otherwise, the frontal cross-section is used to compute air friction, and thus is one of the main concerns (with mass and its distribution a.k.a. inertia matrix) for ship designers like myself, aiming for efficient and fast constructs. Indeed it means that in space, nobody can hear you crying about the bulking shapes of some constructs, since cross-sections don't matter there. 😛 --- Did you know? Atmospheric engines only provide half their power on the vertical axis to begin with, so yes if you provide 1g of vertical thrust with those, your sustentation speed is effectively 0... while they are fueled. At the time of writing I do not know the specifics of how atmospheric density impacts the power of atmospheric engines: they obviously stop at 0%, and min out when you reach high altitude. With a density under 10%, you will need approximatively 1.6 lift more than at sea level, but then the space engines can gradually kick in and help you leave the atmosphere or continue onwards a Suborbital Flight path (which is the most fuel-effective imo). If someone has the formula for calculating the atmospheric density at any given altitude from planet informations like atmosphere thickness and radius, thanks for sharing.

@NQ-Nyzaltar I didn't receive any STU from a long-awaiting sapphire backer status, the package got even wiped from my account (My Products) the day of release when I had to supplement my account with a monthly subscription to be able to play on day one. When DACs were disabled and nowhere to be found anyway days after, though I got 40 by now, no refund for the subscription, don't really mind supporting fro an exytra month at this point. But my patience is really thin. I sent tickets since day one, even keeping them alive, no answer, no reply, no solution and still missing everything but my in-game title. Sound like a sad T-Shirt meme : I backed this game and all I got is... this Sapphire Founder title. At least I'm in the credits lol, yeah me! Nah, to be honest, I got the pioneer reward package and my DACs as well... two Sanctuary territories are "just" free ressources and credits at this point, since all my settlement candidates have long been reserved by someone luckier than me. Have a nice day and safe travels out there.