BRAND NEW DJI FLY APP UPDATE TO 1.6.8

[maggior]

The new update fixed the issue on the smart controller where the arrow indicator showing which way the pilot was facing was off by 90 degrees. Nice to see that fixed.

Very happy with the compass updates.

 

[PacificSkyDreamn]

I think the issue with the attitude indicator (AI), or artificial horizon gauge, is that the programmers that wrote the subroutines for the display are "gamers" and only have experience with flying drones and have never piloted a real aircraft. Therefore, they have no reference to real world situations and circumstances…

Looking at the DJI Manual for the Air 2 they call it an "Aircraft tilt angle" indicator and not an attitude or artificial horizon indicator.

 

[MS Coast]

View attachment 151129
Looking at the DJI Manual for the Air 2 they call it an "Aircraft tilt angle" indicator and not an attitude or artificial horizon indicator.

Actually, they do call it an Attitude Indicator, right there in the title. The same text and illustrations appear n the manual for the Mavic 3 and Mini 3 Pro.

"Aircraft tilt angle" refers only to the roll axis. "Attitude" includes roll and pitch. The display includes both.

I don't care for the version in the 1.6.8 version of the fly app. Eliminating the white bars that represent the wings was a mistake.

The DJI attitude indicator assumes that the horizon is always in the same orientation - level in the display, parallel to the bottom and top edges of the screen. That probably makes sense for quad drones that don't tilt as much as real airplanes.

I sympathize and agree with @Zbip57. The DJI version of the attitude indicator takes some adjustment if you're a conventional pilot. With the "wings" in the display it was less bothersome. This new version will take some more getting used to.

 

[Zbip57]

Straight line is wing not horizon in the app.

It was my understanding that the line is there to indicate the angle of the aircraft's body/wings and not the horizon.

My complaint is that it is simultaneously displaying two entirely different things. It corresponds to the aircraft's wings moving in the roll axis, but then it's showing the horizon moving in the pitch axis. It would be far less confusing if it consistently showed the motion of only one or the other, not a confusing hybrid of both.

If the lines are intended to show the movement of the aircraft, as it apparently does when the aircraft rolls, then why are the lines going UP when the aircraft's nose goes DOWN? Or, if the line is intended to show the movement of the horizon, as it clearly does in the pitch axis, then why is the horizon rolling in the wrong direction as the aircraft rolls?

The display is neither consistent or accurate as an artificial horizon, or as an aircraft attitude indicator. It's a confusing mix of the two.

 

[PacificSkyDreamn]

Actually, they do call it an Attitude Indicator, right there in the title. The same text and illustrations appear n the manual for the Mavic 3 and Mini 3 Pro.

"Aircraft tilt angle" refers only to the roll axis. "Attitude" includes roll and pitch. The display includes both.

I don't care for the version in the 1.6.8 version of the fly app. Eliminating the white bars that represent the wings was a mistake.

The DJI attitude indicator assumes that the horizon is always in the same orientation - level in the display, parallel to the bottom and top edges of the screen. That probably makes sense for quad drones that don't tilt as much as real airplanes.

I sympathize and agree with @Zbip57. The DJI version of the attitude indicator takes some adjustment if you're a conventional pilot. With the "wings" in the display it was less bothersome. This new version will take some more getting used to.

I believe they are referring to the whole display as the "Attitude Indicator." It would be more accurate for them to have titled this section "14. Attitude and heading reference system."

The horizontal line is just the "Aircraft tile angle" indicator and in the updated app its now a solid line with light blue fill below it. The function and purpose didn't change. It has never shown roll and pitch relative to an artificial horizon, just forward looking tile angle of the drone - pitch up/down, tilt left/right.

As you note the flight characteristics of a quad drone and real fixed wing aircraft are not the same.

Yes it is confusing. I wouldn't be surprised if they made the change away from the original two lines as still shown in the manual as many were confusing it with an artificial horizon indicator of an airplane cockpit display that shows the relation the aircraft to the real horizon - the two line would be fixed on the display representing the wings and the horizon line is what moves left/right, up/down.

 

[Zbip57]

Just use black as the sky. Problem solved

Sure, black sky over blue water. But that still doesn't solve the problem.

When the plane's nose dips down, the black sky and blue water horizon line moves up. Or, when the plane's nose is pulled up, the horizon drops down. Fine. That makes perfect sense to me. In pitch, DJI's line moves correctly as though it's showing the horizon.

But when the plane rolls to the right, the horizon line should roll to the left. Here it doesn't. It incorrectly rolls to the right. That's because in the roll axis it's no longer representing the actual horizon. Now we're supposed to picture that line between black/blue as instead representing the wings of the aircraft rolling to the right.

So which is it, horizon or wings? Pick one or the other and make it move consistently.

If the line is intended to be showing the motion of the aircraft, then make the line move DOWN when the nose of the plane goes DOWN. It doesn't. The line goes UP, as it should if it's showing the movement of the horizon.

Or, if the line is intended to show the motion of the horizon, then make it consistently show that. The horizon should roll left as the plane rolls right. It doesn't. Instead of the horizon, now it shows the plane's wings rolling.

As a full scale pilot, I'm accustomed to using an actual artificial horizon instrument, and it certainly doesn't work the way DJI's display moves. I can't even look at that display because it makes me airsick.

 

[Zbip57]

It has never shown roll and pitch relative to an artificial horizon,...

It has always shown pitch relative to the horizon, but roll relative to the aircraft's wings. That's what's so confusing.

 

[Mike107]

It has always shown pitch relative to the horizon, but roll relative to the aircraft's wings. That's what's so confusing.

I agree especially with Mobile Homer that the indicators in a single instrument are coming from two entirely different "absolutes" with one being the environment and the other the aircraft. So which one is it? The aircraft and how control inputs changed its relationship to the environment, or, is it the environment in relation to the aircraft? I would like the option to make it consistent with classic air instrumentation.

I also appreciate the comment regarding developers being game flyers and not plane flyers and how the set up is consistent with games. Anyone know how full-scale drones or commercial instrumentation is set up?
Mike107

 

[Zbip57]

It's just the inconsistency that bugs me. If it showed one or the other consistently it would make more sense.

Show the horizon moving up when the plane pitches nose down, as it's doing now. But then also consistently show the horizon rolling left as the plane rolls right.

Otherwise, show an airplane symbol banking right/left as the aircraft rolls, like it does now, that's fine. But then also show the airplane symbol going down when the airplane's nose pitches down.

I understand how that might be useful. The camera view is gimbal stabilized and doesn't move, so you otherwise have no sense of how much the aircraft is actually moving around.

Instead of the usual Follow-mode for the gimbal, I once (only once) tried the FPV-view. And that's all wrong too! The camera view rolls corresponding to how the aircraft behaves in roll. Right wing goes down, so the camera view correspondingly rolls to the right. Okay, that's cool.

But then you have exactly this scenario, pictured below, on your viewing screen. The plane is banked to the right, so the corresponding camera view is also banked to the right. But, that means the horizon on your viewing screen is rolled to the left. And the lines on the DJI attitude indicator (or the dividing line between the black sky and blue water on the newly revised DJI indicator) is now indicating a bank angle to the right that's twice as far as the aircraft's wings are actually rolled).

I wish they could just lock the gimbal altogether for the FPV-mode. It rolls left/right as the aircraft rolls. That's okay. But the gimbal is still stabilized in pitch. When you move the control stick back or forward, the aircraft's nose pitches up or down, but the camera view remains stabilized level (or at whatever pitch angle the gimbal is currently rotated to). Why not just lock the gimbal entirely? That way the camera view would move the way it actually does with a fixed camera on an FPV drone.

DJI's "FPV-mode" is yet another hybrid invention that's just confusing. Just like their attitude indicator, I only tried it once, declared it useless, and never used it again.

 

[Zbip57]

Anyone know how full-scale drones or commercial instrumentation is set up?

DJI's attitude indicator uses the old Soviet-style horizon indicator, not the more universally accepted Western-style.

In Western-style attitude indicators, the aircraft symbol remains fixed in the face of the instrument. It is the horizon line that moves, the border between the brown earth and blue sky. The horizon line always corresponds to where the horizon is currently located as seen from within the cockpit.

DJI's hybrid indicator works like the Soviet-style indicator. The horizon line moves up and down correctly corresponding to how the horizon actually moves, but it remains fixed in the instrument face as the aircraft rolls. Instead the aircraft symbol rolls to show the aircraft's roll angle.



In my illustration below, you can see the display of the Western-style instrument corresponding precisely to where the horizon actually is.

But the Soviet-style display used in DJI's instrument is doubly confusing because the white lines are showing two completely separate things. In the up/down axis, the lines are correctly showing the "horizon" located higher than the nose of the plane. But in the roll axis, the white lines are instead showing the plane's "wings" rolled to the right.



If you've been trained to use one or the other, either the more commonly used Western-style or the bizarre Soviet-style, then I suppose whichever one you're accustomed to will make more sense to you. But I wish we had a choice to set the instrument to our own preference.

The danger comes from expecting the instrumentation to work in the manner in which you've been trained. DJI's display moves backwards to what I'm used to seeing. For me it's confusing and dangerous, so I don't use it.

In its latest version, DJI replaced the white lines with an even more confusing black sky over blue water. It's completely wrong, unless you're Soviet.

The discrepancy between Soviet-style and Western-style attitude indicators has led to several fatal crashes. Search YouTube for "Crossair Flight 498".

In this documentary, they spend a long time investigating other possible causes of the crash, but from 29 minutes onward they focus on the discrepancy between Soviet-style vs. Western-style artificial horizon instruments.

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At 30:13 in the video this diagram is used to illustrate how a left-bank shown on a Soviet display might be confused with a right-bank shown on a Western display.


I find that even more confusing because it actually does show the plane in two different attitudes. So here's how it would look with the aircraft banked to the right in both cases.


And below is how it would look inside the plane, with the nose pointed at the horizon and the plane rolled to the right. Note the Western-style display accurately and intuitively corresponds to where the horizon is currently located. The Soviet-style (and DJI) instrument instead confusingly shows the horizon fixed level inside the display and the plane's wings rolled to the right, neither of which bear any resemblance to what is seen through the windshield.

 

[Pallidin]

Interesting comments.
Hope DJI is reading them.

 

[Zbip57]

Interesting comments.
Hope DJI is reading them.

I can see arguments for having it either way.

As a pilot, I'm used to sitting in the cockpit and having my body move with the plane. As the cockpit rolls left or right, I always know (hope!) my wings are still attached in the same place outside my left or right window. The wings never move relative to where I'm sitting. I'm much more concerned about knowing where the horizon has gone. As long as you have a constant 1g acceleration holding you in your seat, your brain will convince you that you're still flying straight and level. You could be in a descending spiral and never even know it or feel it, unless you can see the actual horizon or trust your instruments. If you've grown up using flight sims on your computer, you'll know exactly how an artificial horizon works.

On the other hand, we're flying remote controlled drones. We're safely standing or sitting on the ground. We are not being subjected to any other external g forces, so our head always knows which way is up, and we know where the horizon is located at all times, and we know it ain't moving. So maybe it is more useful to have a display leaving the horizon level and instead showing how far the aircraft's "wings" are rolled to the right or the left. But if that's the case, then why is the instrument showing the aircraft's "wings" going up when the plane's nose is pitched down in forward flight? That's because, in the pitch axis, instead of showing the wings moving, the instrument is instead showing the horizon moving. The horizon goes up as the nose goes down.

That's what's hurting my head.

When I look at that I see the "horizon" moving the the right way in the pitch axis, but the wrong way in the roll axis. Or I see the "wings" moving the right way in the roll axis, but the wrong way in the pitch axis. It just doesn't click intuitively for me that the instrument is supposed to be showing "wings" in roll, but "horizon" in pitch. My head is just not wired that way.

 

[maelstrom]

On the other hand, we're flying remote controlled drones. We're safely standing or sitting on the ground. We are not being subjected to any other external g forces, so our head always knows which way is up, and we know where the horizon is located at all times, and we know it ain't moving. So maybe it is more useful to have a display leaving the horizon level and instead showing how far the aircraft's "wings" are rolled to the right or the left. But if that's the case, then why is the instrument showing the aircraft's "wings" going up when the plane's nose is pitched down in forward flight?

When you're in an aircraft, the horizon moves relative to you and the aircraft, so I agree with you that it's more natural to show that on the artificial horizon. But as you also pointed out, when flying a drone the horizon remains fixed relative to you and the controller, and the drone, as viewed from your perspective (and as depicted by the Fly app), moves relative to the horizon. If you were flying a FPV drone, it would make more sense to show the horizon moving on the display because that's what you'd see through the goggles. For someone who has no experience of real-world flying (and hence is unfamiliar with real flight instruments), showing the horizon fixed in roll on the DJI instrument is probably a more logical way of doing it.

In pitch, the DJI display just continues the format used by the Russian/Soviet style instrument where the aircraft symbol remains fixed in roll and the horizon moves in pitch, which is probably just a compromise to prevent the aircraft symbol potentially disappearing, or at least partially disappearing, off the top or bottom of the display at extreme pitch attitudes. That said, extreme pitch attitudes in most drones are usually of very short duration so continuing to show the aircraft symbol also moving in pitch relative to the horizon would be more logical and consistent. It would be useful if they gave us the option to use the format which made more sense to us, personally.

 

[MS Coast]

I can see arguments for having it either way.

As a pilot, I'm used to sitting in the cockpit and having my body move with the plane. As the cockpit rolls left or right, I always know (hope!) my wings are still attached in the same place outside my left or right window. The wings never move relative to where I'm sitting. I'm much more concerned about knowing where the horizon has gone. As long as you have a constant 1g acceleration holding you in your seat, your brain will convince you that you're still flying straight and level. You could be in a descending spiral and never even know it or feel it, unless you can see the actual horizon or trust your instruments. If you've grown up using flight sims on your computer, you'll know exactly how an artificial horizon works.

On the other hand, we're flying remote controlled drones. We're safely standing or sitting on the ground. We are not being subjected to any other external g forces, so our head always knows which way is up, and we know where the horizon is located at all times, and we know it ain't moving. So maybe it is more useful to have a display leaving the horizon level and instead showing how far the aircraft's "wings" are rolled to the right or the left. But if that's the case, then why is the instrument showing the aircraft's "wings" going up when the plane's nose is pitched down in forward flight? That's because, in the pitch axis, instead of showing the wings moving, the instrument is instead showing the horizon moving. The horizon goes up as the nose goes down.

That's what's hurting my head.

When I look at that I see the "horizon" moving the the right way in the pitch axis, but the wrong way in the roll axis. Or I see the "wings" moving the right way in the roll axis, but the wrong way in the pitch axis. It just doesn't click intuitively for me that the instrument is supposed to be showing "wings" in roll, but "horizon" in pitch. My head is just not wired that way.

Amen.

I can understand DJI choosing to display the roll axis as they do, though I don't like it. But displaying pitch in the opposite mode makes absolutely no sense. Adopt one convention or another, but don't mix both.

Now, for more airplane/drone confusion, let's talk about labeling the fore & aft movement of the left stick the "throttle." It has absolutely nothing to do with aircraft speed.

 

[maelstrom]

Adopt one convention or another, but don't mix both.

But all they've done is to adopt the Russian/Soviet style of instrument which shows it exactly this way (horizon fixed in roll but moving in pitch). It would certainly have been more logical, and more consistent, to keep the horizon fixed in both pitch and roll.

 

[Zbip57]

If you were flying a FPV drone [with a fixed camera], it would make more sense to show the horizon moving on the display because that's what you'd see through the goggles.

Correct.

But that's yet another reason the current attitude indicator is so confusing. Most of us flying camera drones see only a gimbal-stabilized image on our monitor screens. The aircraft can be pitching and rolling every which way, but the horizon never appears to move at all.

So why not make the instrument show a constant fixed level horizon line, while showing the aircraft symbol pitch and roll corresponding to how the aircraft is actually moving?

On the Fly app for my Mini, there's an option to switch the gimbal from it's normal "Follow-mode" to a simulated "FPV-mode". In that case, the horizon does roll on the monitor screen as the camera rolls fixed with the aircraft's "wings". Now we have the confusing attitude indicator showing the horizon remain level but the "wings" rolling side-to-side, when that's not what's showing on the camera monitor.

And even more confusing, with the gimbal in "FPV-mode", the camera only rolls with the aircraft, but remains gimbal-stabilized in pitch. The horizon displayed on the camera monitor screen never moves up or down as it would when the aircraft's nose pitches down or up. So. again, what's the point of showing the horizon moving in pitch on the attitude indicator?

 

[Zbip57]

Now, for more airplane/drone confusion, let's talk about labelling the fore & aft movement of the left stick the "throttle." It has absolutely nothing to do with aircraft speed.

I don't have an issue with that one.

"Throttle" controls engine speed on aircraft, and motor speeds on drones. Neither actually are directly used to adjust aircraft/drone airspeed.

Yes, of course, a fixed wing aircraft requires engine speed to maintain forward airspeed, as does a drone to maintain hover. But once at any set cruising speed, fixed wing airspeed is more immediately controlled by the elevator and aircraft pitch angle. Pitch the nose up, the aircraft slows. Pitch nose down, it speeds up. That works the same for any fixed wing aircraft, even if it has no engine at all like a glider.

Increasing throttle allows the plane to climb without slowing. Decreasing throttle allows the plane to descend without excessive speed. Throttle is therefore used to adjust rate of climb.

It's the same with drones. Pitch angle changes the airspeed, with the flight controller automatically adjusting motor speed to maintain constant altitude. Throttle is used to increase/decrease altitude.

 

[MS Coast]

But all they've done is to adopt the Russian/Soviet style of instrument which shows it exactly this way (horizon fixed in roll but moving in pitch). It would certainly have been more logical, and more consistent, to keep the horizon fixed in both pitch and roll.

I'm speaking from the point of view of a westerner, not a Russian. They kept one aspect, pitch, of the western style and adopted one aspect, roll, from the Russian style.

 

[MS Coast]

"Throttle" controls engine speed on aircraft, and motor speeds on drones. Neither actually are directly used to adjust aircraft/drone airspeed.

The weather is good, so I don't want to spend too much time at a keyboard.

On an airplane the throttle controls the engine speed. A direct and singular relationship. On a drone, both the left stick and the right stick control motor speed and airspeed.

Yes, of course, a fixed wing aircraft requires engine speed to maintain forward airspeed, as does a drone to maintain hover. But once at any set cruising speed, fixed wing airspeed is more immediately controlled by the elevator and aircraft pitch angle. Pitch the nose up, the aircraft slows. Pitch nose down, it speeds up. That works the same for any fixed wing aircraft, even if it has no engine at all like a glider.

Yes, I have a little time in both power planes and gliders.

Increasing throttle allows the plane to climb without slowing. Decreasing throttle allows the plane to descend without excessive speed. Throttle is therefore used to adjust rate of climb.

Yes, via a change in the speed/power of the engine caused by adjusting the throttle.

The throttle is also used to adjust the engine speed/power to increase or decrease aircraft speed at constant altitude.

In both cases, the throttle gives the pilot direct control over the speed/power of the engine. On a drone, two controls give the pilot control of the motor speed/power. One could argue with justification that the right stick fore/aft movement should be called the throttle rather than the left. That would probably make more sense to non-airplane pilots accustomed to operating in only two dimensions. Most probably see speed only in terms of motion over the ground, without consideration of altitude.

It's the same with drones. Pitch angle changes the airspeed, with the flight controller automatically adjusting motor speed to maintain constant altitude. Throttle is used to increase/decrease altitude.

The singular relationship between throttle setting and motor speed/power is not there in a drone. The so-called "throttle" controls only motor speed/power for climbing and descending. The right stick controls also controls speed in the horizontal plane.

It's a trivial thing, but there is a substantial difference in the throttle in an airplane and in a drone. I'd have preferred a different term. Altitude control?

Remember those joke instrument labels that someone produced when VW Beetles first arrived in the U.S.? "Der honkenbeepen" and "der drizzleflippin" were two of the best. Maybe the left stick forward/aft motion should have been "der upendownen."

 

[maelstrom]

I'm speaking from the point of view of a westerner, not a Russian. They kept one aspect, pitch, of the western style and adopted one aspect, roll, from the Russian style.

It's a straight copy the Russian style instrument, The fact that the horizon moves in pitch like western style instruments is just a coincidence.