Is it possible to bypass the DJI Mini 4 Pro's 120-meter height limit without triggering the Remote ID?

[GadgetGuy]

Based on some testing and other comments. The Mini 4 Pro activates RID when you put in a Plus battery and take off. The RID also activates when you use the 249 battery that came with the Mini 3. It works in the Mini 4, but is slightly heavier, so the battery ID activates RID as well (marked BW160 on the case). If you put a Mini 4 Pro 249 battery back in (BW140), it will disable RID after one flight. This is with US specific software. If you want to investigate yourself, the RID broadcast is a WiFi and Bluetooth signal. Use a laptop with the find network box open. When your drone starts transmitting (you must be at least in a hover), it will show up as a WiFi network with the prefix RID....

I'm a little confused by your statement that,

"If you put a Mini 4 Pro 249 battery back in (BW140), it will disable RID after one flight."

My understanding of the Mini 4 Pro is that, no matter what battery you previously flew in the drone, RID is never transmitted when you fly with the 249g Mavic 4 Pro battery. The RID transmission of each flight is totally dependent upon the current battery being used, not the prior battery.

Are you suggesting otherwise?

 

[Dogpilot]

No, it does not immediately switch off the RID broadcast. It was a bit confusing when I did the testing. I would swap and it still didn't switch off RID. Then I would fly again and it would be off. So I tested it specifically looking for that response and it did act like it needed to fly once and then toggle off the next flight. Now it may no longer have this behavior since recent updates of firmware. I have not done testing since.

I needed to find out when they broadcast since during the AfrikaBurn event, I am in charge of airspace and the de-facto drone police. I still confiscated several Mini 3 Pro's. RID or not, 4 guys with handi talkies have no problem locating the operator, even in 12,000 participants.

 

[GadgetGuy]

No, it does not immediately switch off the RID broadcast. It was a bit confusing when I did the testing. I would swap and it still didn't switch off RID. Then I would fly again and it would be off. So I tested it specifically looking for that response and it did act like it needed to fly once and then toggle off the next flight. Now it may no longer have this behavior since recent updates of firmware. I have not done testing since.

I needed to find out when they broadcast since during the AfrikaBurn event, I am in charge of airspace and the de-facto drone police. I still confiscated several Mini 3 Pro's. RID or not, 4 guys with handi talkies have no problem locating the operator, even in 12,000 participants.

Thanks for the heads up! I'll make sure to test myself before flying and naively expecting it to be off by simply changing batteries.

How long ago did you do your testing?

That VLOS requirement, if complied with, certainly limits the search area, even without RID. Scofflaws may be able to outrun a cop, but they can't outrun the radio! LOL!

 

[MS Coast]

The result is perfectly incoherent with the regulation. For example, if your drone takes off from 1000ft ASL, it won't be able to climb higher than 1400 ASL because 1000ft become 0ft AGL as a refence. So, if you fly along a hill, down or up, the drone won't be able to respect any height regulation at all. Figure that you are 400ft below the hill to where you want to fly, you will soon crash into the ground because the drone won't let you climb high enough. And the funniest example is when your drone takes off from way above where you plan to fly. The result is that your drone will let you blasting the height limit as high as the differential from you and the bottom of the valley.

The 400' AGL limitation in the US regulations has nothing to do with takeoff elevation. The regulations state very simply and coherently that you must not fly the drone more than 400 feet above the ground level directly below it.

You can legally fly up the slope of a mountain to several thousand feet above the takeoff location as long as you stay within 400' of the ground below the drone. Similarly, you cannot legally fly over a deep canyon unless you descend to keep the drone within 400' of the ground below. Takeoff elevation is not relevant to either case.

 

[GadgetGuy]

The 400' AGL limitation in the US regulations has nothing to do with takeoff elevation. The regulations state very simply and coherently that you must not fly the drone more than 400 feet above the ground level directly below it.

You can legally fly up the slope of a mountain to several thousand feet above the takeoff location as long as you stay within 400' of the ground below the drone. Similarly, you cannot legally fly over a deep canyon unless you descend to keep the drone within 400' of the ground below. Takeoff elevation is not relevant to either case.

Exactly! Very widely misunderstood. Too bad DJI assumes the world is flat, and always makes the launch point zero elevation! LOL!

DJI prevents mountain climbing along the slope beyond 500m, unless it's 1000m on an Air 3S, or Mavic series 3 or 4, or over 50km from the nearest airport.
Although it could be argued that VLOS is violated when mountain climbing along the slope on larger elevation changes.

Only alternative to reach a higher summit is to hike higher to start.

 

[Dogpilot]

GG, did the testing exactly last September. I had just purchased another Mini 4 Pro fly more kit. It came, erroneously, 1 plus and two Mini 3 249 batteries. So I had to buy some Mini 4 batteries and sell the M3 batteries. However for a bit I had all three types.

I do use drone scanner at the event, but really I tended to just sight them visually, as did my crew. I finally got tired of chasing around the fools. It is actually a serious crime in South Africa to fly at the event. Airspace is a National Park, we have an active airport and two heliports, one exclusively for MEDIVAC. So I actually have other stuff I would rather do than deal with drones. So The last two years we had signage that not only would we confiscate them, but we would destroy them. With a cricket bat. If they argue, I turn them over to the regular Law Enforcement, which puts them in jail.

Guess what, not a single drone in two years! The year before, I alone confiscated 15. Sometimes you just have to be a twit to get the point across.

Drone Scanner, on an Android phone, can pick up a Mavic 3 at 450 meters horizontally, hovering two meters off the ground. For me at least. So I can cover the entire event if I am at the center. Just do not find it entertaining to stare at my phone.

 

[Meta4]

So, drones stupidly calculate AGL altitude from ASL (MSL in USA)

Your drone doesn't calculate AGL altitude at all, but if it did it wouldn't be relative to MSL.
Your drone only calculates it's height relative to where you launched (Home = zero feet).

The result is perfectly incoherent with the regulation. For example, if your drone takes off from 1000ft ASL, it won't be able to climb higher than 1400 ASL because 1000ft become 0ft AGL as a refence.
So, if you fly along a hill, down or up, the drone won't be able to respect any height regulation at all. Figure that you are 400ft below the hill to where you want to fly, you will soon crash into the ground because the drone won't let you climb high enough.

Sometimes you have to use your brain to assist in your flight management.
You aren't stuck with a 400 max height limit.
Your drone has a max height limit that is user configurable up to 1640 ft higher than your launch point.

And the funniest example is when your drone takes off from way above where you plan to fly. The result is that your drone will let you blasting the height limit as high as the differential from you and the bottom of the valley.

Since your drone has no sensor capable of measuring height above the ground, it's up to you to work things out sometimes, just like the pilots of most general aviation aircraft manage to.

 

[GadgetGuy]

GG, did the testing exactly last September. I had just purchased another Mini 4 Pro fly more kit. It came, erroneously, 1 plus and two Mini 3 249 batteries. So I had to buy some Mini 4 batteries and sell the M3 batteries. However for a bit I had all three types.

I do use drone scanner at the event, but really I tended to just sight them visually, as did my crew. I finally got tired of chasing around the fools. It is actually a serious crime in South Africa to fly at the event. Airspace is a National Park, we have an active airport and two heliports, one exclusively for MEDIVAC. So I actually have other stuff I would rather do than deal with drones. So The last two years we had signage that not only would we confiscate them, but we would destroy them. With a cricket bat. If they argue, I turn them over to the regular Law Enforcement, which puts them in jail.

Guess what, not a single drone in two years! The year before, I alone confiscated 15. Sometimes you just have to be a twit to get the point across.

Drone Scanner, on an Android phone, can pick up a Mavic 3 at 450 meters horizontally, hovering two meters off the ground. For me at least. So I can cover the entire event if I am at the center. Just do not find it entertaining to stare at my phone.

Cool. I'll soon discover whether it has changed over the last year. I have all 3 types of batteries as well, and had to separately buy three Mini 4 Pro regular batteries because the only available DJI Refurb Mini 4 Pro was the Plus version, and I thereafter discovered my regular Mini 3 Pro batteries are 2 grams too heavy for the Mini 4 Pro to not broadcast RID and remain registration free. Glad to know that if I ever fly with any of the others, it will take one additional flight to flush out the RID broadcasting. I just acquired a Dronetag Rider RID receiver to track all RID broadcasting drone flights within 3-5 miles, depending upon which antenna I attach it to. Still setting it up.