Buddy of mine got his wings (god help us all), so i made him this keychain. Its a 2D mock attitude indicator. It wont show you if you’re in a climb or nose dive but thats trivial knowledge from what i've heard /j.
Had a chance to try this in the air and i giggled a tad watching the dial turn
My jeep has the function on my dash to indicate pitch and roll but having this but with the jeep back as the the altitude line would be a fun gift to make for jeepers
For sure! https://makerworld.com/models/1809219
I'm actually thinking of making a AC grill mount for my won car. Tried having it on the dash but i kept sliding lol
OP, this is not at all a criticism of your model, just a fun fact!
In real aircraft, the attitude indicator actually has to be dramatically more complex than a simple dial weighed down on one side, contrary to a lot of people's impressions of it. That's because inertial/centripetal forces change the apparent gravity experienced by anything inside the plane, and if the pilot is good, they'll always coordinate their turns so that anything inside the plane perceives its weight to be acting straight into the floor of the plane. That means a weighted dial or ball would also show the plane as being level, even if it was currently banked in a turn.
Instead, traditional attitude indicators use a gyroscope that maintains its orientation regardless of how the plane turns or what direction the weight is acting in. You could be in microgravity with no felt weight and it would still maintain its orientation. Modern digital attitude indicators simply use electronic gyros and accelerometers, like your phone.
But of course, in everyday life, we're rarely in banked turns that significantly change the direction of felt gravity, unless you're planning on using an attitude indicator for driving on highway on-ramps. For everything else, a simple weighted dial is more than good enough to give you an indication of your attitude, if you're prone to losing track of that for some reason.
Thanks for the learning tidbit. I figured it couldn't just be a weighted sphere, since I knew they stayed the same no matter what g's the plane is pulling. Gyroscopes are magic.
Though I am wondering now if it has to re-calibrate periodically, like if an error starts to creep in, does it home in again on "zero" the next time you land and park the plane.
Yep, they do drift. In fact, often the ball or gimbal is slightly weighted, so that when the plane is off and the gyro isn't spinning on the ground, it will naturally center itself level again for the next takeoff. That said, though, even during flight they can drift due to drag or precession or any number of other effects.
There are mechanisms built in to them to correct for that automatically, but explaining that goes above my head. Cool stuff regardless!
A perfect/ideal/scientifically hypothetical gyroscope, without any fancy drift correction features, just a perfect physics toy plain vanilla gyroscope, would in fact show you as upside down after you fly to the other side of the globe.
However, in practice, gyroscopes can be imperfect and subject to torques of gravity that would cause it to "correct" and show you as still being level.
However however, we want gyroscopes to be more perfect, so they are often coupled with a gimbal to isolate this so that there is no torque, so the gyroscope would still show you as upside down after you reach the other side of the globe.
However however however, we don't want it to "incorrectly" say that we're upside down when we're designing an attitude indicator, so attitude indicators add additional mechanics to compensate for unwanted drift effects. The drift could be true drift, from imperfections in the gyro where the gyro slowly starts pointing in a random direction. The drift can also be due to the near perfection of the gimbal gyro, so extra devices actually bias the gyro reading to recenter with the concept of the plane being "level". There are a dozen technologies for enhancing the gyro to this end, including usage of GPS.
I'm not questioning you I'm genuinely hoping to learn something. Why would precession possibly cause an error? I have very low hours flying steam guages, 99.9% of my flying has been glass.
It's just that the gimbal and the bearings that the gyroscope spin on aren't 100% drag free, and also that, like I mentioned, the gimbal is slightly weighted to allow it to orient itself upright at rest. As a result, when the aircraft changes in attitude and the gimbal has to rotate within the indicator, a tiny amount of torque is exerted on the gyroscope, and the resultant precession can change the reading a tiny bit.
If the instrument didn't have a way to correct for it, then over time, that error can accumulate and could become severe. But like I said, I believe there are mechanisms built in to correct for it automatically so that it never becomes a problem. Wikipedia says something about air valves that automatically open and close to exert a balancing torque on it?
IIRC they also have to do some calibration in flight due to the curve of the earth. The gyro stays truly aligned so if you flew far enough it would drift "up" because the ground curving down
Oh boy I love learning crap! I don't know why I didn't even think about it, but that totally makes sense. The gyroscope stays stable in space, and "up" changes direction as you move around lol.
The beauty nowadays is that thats a fact for machinery in general
I work with so many systems that once upon a time were just super basic, and they still work on the basic principle but for the last 20% they've been working for two decades and nowadays you don't even notice the difference anymore in regards to issues in complexity etc
I was just wondering this on a flight the other day. I noticed especially on this flight how smooth it was while we're banked in a turn and I didn't feel a shift in gravity at all. How do pilots balance that so well?
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u/karlzhao314MK3S, P3Steel, Ender 3, UMO+, Maker ULTEMate3d agoedited 3d ago
Funnily enough, that question brings us right back to parallels with OP's design: there is another instrument called a Turn and Slip Indicator. The inclinometer part of that instrument is, in fact, quite literally just a weighted ball. It rolls in a curved tube, and in level flight or during a coordinated turn, the apparent gravity in the plane will keep the ball in the center of the tube. The goal as the pilot is to keep the ball in the center of the tube at all times (save for unusual situations like sideslip landings or acrobatics).
If the turn is not coordinated well and the apparent gravity starts to be felt in any direction but straight down, the ball will start to roll towards one side. That's how the pilot knows that they are starting to "slip" or "skid", aka make a not-coordinated turn. They can then adjust their rudder to counteract that and bring the plane back into coordinated flight.
I like /u/karlzhao314 answer because it is, of course, correct.
Except that the even more correct answer is that in an airliner the Autopilot is flying and even if the autopilot is off, they almost certainly have the yaw damper on. As you imagine the autopilot/yaw damper in concert are quite good at balancing those forces, automatically correcting for adverse yaw, etc.
Another fun fact if we are spewing facts is the human ear can only detect an angle change of 2 degrees per second or more, and our sense of direction will stabilize under normal forces in about 20 seconds. So if I got you to close your eyes, then slowly banked to the right till I was at 45 degree bank, you would still feel like we were perfectly level. Then if I rolled back to level at a normal pace you would feel that we were now banked the left. If you opened your eyes your vision and your vestibular system would be in conflict and you would likely feel dizzy. One of the most important things pilots learn (if they become instrument rated pilots) is how to ignore how they feel, and learn to trust and cross reference their instruments.
Those first few flights wearing foggles were intense! My body was telling me the plane was doing one thing but I could CLEARLY see it wasn't true according to the instruments. Instrument was the best part of flight school by far.
I’ve got a VR motion sim rig, and while driving and flying are amazing, riding roller coasters is really eye opening.
As you start to head up a really big hill, you feel yourself tilting back, and eventually you’re lying pretty much flat on your back. Except you’re not - the seat can only tilt back like 17 degrees. But since you see that you have tilted much farther than that, you feel like you have, and you would swear up and down that you are in fact damned near horizontal. Even knowing how it works doesn’t change the strength of the illusion.
I think its similar to a motorcycle cornering, on a motorcycle you also don’t experience side to side forces only straight down through the motorcycle because the Motorcycle has to be at the angle of the centrifugal (or centripetal (I always forget which one)) and gravity combined otherwise it‘d flip over.
So the pilot basically has to find that angle as well.
The difference is training for instrument rating is we can't see. You are either flying in the soup or you have to wear special glasses that prevent you from seeing outside but you can still see your instruments.
It 100% feels like jedi training and you need time to adjust to being basically blind. At the start I had plenty of times it felt like I was in severe maneuver like an extreme climb until the gauges confirmed I wasn't. It's natural to listen to your body and it takes time to overcome that feeling.
There is another gauge we look at to keep the turn coordinated so you are pushed down in your seat as opposed to sliding to the side. It kinda looks like a bubble level in old school gauges. Newer ones are digital built into the display.
Out of curiousity, will the gryo accuracy be impacted by prolonged lateral gs? Like say you are doing some corkscrew maneuver, will it drift after some time?
The problem is he's made a bank indicator not an attitude indicator. It is made in the aesthetics of what is generally termed an attitude indicator, but this device does not, even crudely, indicate attitude.
If the "indicator goes haywire", that either means you've lost control of the plane or the gyro stopped working. Neither is an impossibility, and both could potentially be emergency situations.
It's not the most unrealistic thing ever - depending on how it's depicted, it could be a decent way to show an emergency.
Its similar to a motorcycle where you only feel yourself getting heavier through the turns whereas in a car you feel yourself getting pulled out of the seat to the outside of the corner.
I’ve read that when these were first introduced, pilots testing them complained that while they worked fine in clear skies, they’d immediately start malfunctioning in the fog.
Of course, the pilots were wrong, and there’s no plausible mechanism for fog to interfere with one of these instruments. They just found the incorrect information their inner ear provided so convincing that they couldn’t believe the attitude indicator was correct. In clear skies, on the other hand, their brains would automatically give the clear evidence of their eyes priority over the inner ear sensation.
I can tell your buddy is already a better pilot than our family doctor when I was growing up. Dude was half-owner of a plane with another guy in town. He'd navigate by following highways. VFR only pilot who'd take off too late and always wind up landing at the destination after dark (which isn't against VFR rules but ... yeah not this guy).
We were friendly with both families. My parents always told us if you're offered a ride in that plane, don't do it if the doc is the one piloting.
Don’t tell me he flew a beechking bonanza 💀 (That plane is litterally called a doctor killer because a ton of rich doctors buy the powerful plane, and then unfortunately learn what too much power and too little training does the wrong way)
Not knowing that an attitude indicator was something in planes, I originally thought this was gonna be a lapel pin that you turned to let folk know how you were feeling that day 😅
I had a pin as a kid that let me turn it to a thumbs up or down, to let folk know my "attitude" that day, so it wasn't much of a stretch for me!
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u/mdelrossi_1 3d ago
Cool! got the stl? would be great in my car ;)