Crashed Mini 2

[Clintoops]

Thank you! I've downloaded a couple of apps that were recommended on the TRUST. I'll check out the weather conditions app...

Your welcome

 

[MS Coast]

Thank you! I've downloaded a couple of apps that were recommended on the TRUST. I'll check out the weather conditions app...

The B4YOUFLY app is particularly useful for checking on limitations in the area you plan to fly.

 

[John Locke]

Isn't it true that if your drone is less than 250Gm, it does not need to be registered?

That's correct, you don't have to register the Mini2 in stock form.

 

[MS Coast]

Yes but if you add anything that brings it above 250GM your over the limit. Welcome there are some good apps for your phone that are helpful Uav forecast shows airports near you weather conditions too . Best of luck.

Don't fret about registration. It's not a big deal and it only costs $5 and it's valid for three years. You're actually registering yourself and the registration is good for all the drones you own and fly recreationally.

https://www.faa.gov/uas/getting_started/register_drone/#:~:text=Registration%20Fees,the%20Exception%20for%20Recreational%20Flyers).

 

[okw]

First, you say you're only had this drone for 4 days. And since you flew from inside your home, I'm guessing (maybe incorrectly) that you didn't take the TRUST training for recreational flyers. If you had, you would have known that flying from inside the home is against the rules. Recreational rules require that "The aircraft is flown within the visual line of sight of the person operating the aircraft or a visual observer co-located and in direct communication with the operator." This is the Visual Line of Sight rules (VLOS).

I'm a little confused. The quoted regulation doesn't say anything about flying from inside a structure. I've flown in cold temperatures while standing inside my home looking out a large picture window. I had direct line of sight of the quad the entire time it was in the air and was never more than than a couple hundred feet away or 50' AGL. What about that is against the VLOS rules?

 

[Vic Moss]

I'm a little confused. The quoted regulation doesn't say anything about flying from inside a structure. I've flown in cold temperatures while standing inside my home looking out a large picture window. I had direct line of sight of the quad the entire time it was in the air and was never more than than a couple hundred feet away or 50' AGL. What about that is against the VLOS rules?

It's about maintaining line of sight. You can't do that if you're inside your home. You have to maintain situational awareness, and that's impossible from inside.

 

[Clintoops]

If you had been outside you would may have not crashed.

 

[clintonamoar]

It looks like you have your reason above about the why. I'd like to put my FAASTeam hat on for a minute and make some assumptions (I may be wrong, but I don't think so).

First, you say you're only had this drone for 4 days. And since you flew from inside your home, I'm guessing (maybe incorrectly) that you didn't take the TRUST training for recreational flyers. If you had, you would have known that flying from inside the home is against the rules. Recreational rules require that "The aircraft is flown within the visual line of sight of the person operating the aircraft or a visual observer co-located and in direct communication with the operator." This is the Visual Line of Sight rules (VLOS).

Judging from your flight records, it's obvious you didn't maintain VLOS.

Once you get your drone back I suggest your take the TRUST (FAA TRUST Online Portal for Recreational Drone Operators - Pilot Institute) and make sure you understand the rules. And remember, battery life and performance are both affected by low temperatures.

Full set of recreational rules can be found here: https://uscode.house.gov/view.xhtml...lim-title49-section44809&num=0&edition=prelim

Thank you for your detailed reply! Your guess is very reasonable, but incorrect. I have taken the TRUST this summer and did not print out the certificate when I did, but decided to re-take it just now. I acknowledge that I broke the VLOS rules, for which I take full responsibility, but I didn't see any mention of a rule that prohibits flying inside the home. As you could see, I had a large window in front of me, which allows for VLOS to be maintained during the whole flight, so long as I don't fly behind my house again like I did.

While I have only had this drone, the Mini 2, for 4 days, I have previous experience flying FPV racing quads with several hours in sims and several hours flying the actual thing. Not saying I'm an expert pilot, but I'm certainly not a first-timer either.

I also took a calculated risk flying in the cold, but I justified it because in all my previous flights, the battery never dipped below 69F (20.5C). As for ice accumulation, I decided to monitor how the AC was flying and if I noticed anything abnormal that I would bring the AC back immediately. Would you say those two decisions were poor judgement on my part?

 

[Vic Moss]

Thank you for your detailed reply! Your guess is very reasonable, but incorrect. I have taken the TRUST this summer and did not print out the certificate when I did, but decided to re-take it just now. I acknowledge that I broke the VLOS rules, for which I take full responsibility, but I didn't see any mention of a rule that prohibits flying inside the home. As you could see, I had a large window in front of me, which allows for VLOS to be maintained during the whole flight, so long as I don't fly behind my house again like I did.

While I have only had this drone, the Mini 2, for 4 days, I have previous experience flying FPV racing quads with several hours in sims and several hours flying the actual thing. Not saying I'm an expert pilot, but I'm certainly not a first-timer either.

I also took a calculated risk flying in the cold, but I justified it because in all my previous flights, the battery never dipped below 69F (20.5C). As for ice accumulation, I decided to monitor how the AC was flying and if I noticed anything abnormal that I would bring the AC back immediately. Would you say those two decisions were poor judgement on my part?

My concern would be your ability to maintain situational awareness. You can't see what's going on in the airspace around you. That would be the issue.

We've all flown past our ability to see our drone (anyone who says otherwise is lying or just bought their drone), but in your case, it would be a the inability to see around you.

Thanks for replying. It's all about learning when we fly. Let me know if you have any more questions. I'm here to help.

 

[okw]

It's about maintaining line of sight. You can't do that if you're inside your home. You have to maintain situational awareness, and that's impossible from inside.

Again, I don't understand. I had the quad in sight the entire flight. From the time it left the ground to the time it landed. I had nearly a 180 degree field of view, though the only thing there is to see is the trees that were higher than the quad.

I will admit that I could not see what was behind me. But there is only a 400+ foot high hill and more trees back there. So virtually impossible for any aircraft to approach from that direction. And if there were an aircraft in the area, the only way my quad would have been a danger to it is if it was landing in my front yard.

I'm not trying to be argumentative. I'd just like to understand the rules as best as I can.

 

[Vic Moss]

Again, I don't understand. I had the quad in sight the entire flight. From the time it left the ground to the time it landed. I had nearly a 180 degree field of view, though the only thing there is to see is the trees that were higher than the quad.

I will admit that I could not see what was behind me. But there is only a 400+ foot high hill and more trees back there. So virtually impossible for any aircraft to approach from that direction. And if there were an aircraft in the area, the only was my quad would have been a danger to it is if it was landing in my front yard.

I'm not trying to be argumentative. I'd just like to understand the rules as best as I can.

See comment above. And don't worry about being argumentative. It's all about helping everyone understand the rules and fly safe.

 

[clintonamoar]

My concern would be your ability to maintain situational awareness. You can't see what's going on in the airspace around you. That would be the issue.

We've all flown past our ability to see our drone (anyone who says otherwise is lying or just bought their drone), but in your case, it would be a the inability to see around you.

Thanks for replying. It's all about learning when we fly. Let me know if you have any more questions. I'm here to help.

You're very right and I plan to change how I fly in the future (ie increasing situational awareness). Glad there's no worry about seeming argumentative

As for other questions, do you feel it is irresponsible to fly in the cold so long as you know your batteries are pre-heated and won't drop below ~ 70F (20C) and also acknowledge the risk of ice forming?

Also, is flying 3-5ft from a building really that likely to drop GPS signal enough to cause a glitch like what happened? I certainly will be staying much further away from buildings in future flights, but I'm having trouble understanding how the crash is 100% my fault.

 

[Vic Moss]

You're very right and I plan to change how I fly in the future (ie increasing situational awareness). Glad there's no worry about seeming argumentative

As for other questions, do you feel it is irresponsible to fly in the cold so long as you know your batteries are pre-heated and won't drop below ~ 70F (20C) and also acknowledge the risk of ice forming?

Ice is always a potential issue in the cold. If I suspect icing, I'll fly up about 50' and let it hover for a few minutes. Then I'll land and check the props. I'm in Colorado, so I fly in cold weather a lot! Definitely not irresponsible if done safely.

Also, is flying 3-5ft from a building really that likely to drop GPS signal enough to cause a glitch like what happened? I certainly will be staying much further away from buildings in future flights, but I'm having trouble understanding how the crash is 100% my fault.

It could cause that issue, but it shouldn't make it fly off like that. One thing I did notice in the video, although it's hard to know for sure, it looks like you may have inadvertently flown the drone into the window. It looks like you may have been pushing the right stick forward, and since the drone was facing you, it flew into the window. I can't tell for sure.

This is actually why I launch and land with the drone facing away from me. Always, and I have 100s of hours in the air, and 1000s of launches and landings. It's something I teach when I teach new pilots.

 

[clintonamoar]

Looking into the log & comparing that with the video of the crash you shared in post #7 give away the reason for this.

According to your video you came in towards the window, pitched up your camera & descended step wise ... then slowly approached the window again & hovered. Right there you were under that patio which effectively shielded the sky making the GPS level (positional quality or the trust the IMU have in the GPS position) go from maximum 5 to a lousy 3 (HP isn't recorded until 4 for instance...).

From there the log records that the AC goes backwards with 63,5mph then forward with 74,1mph & crashes (unrealistic speeds well above the specs for a Mini 2) ... at the same time the AC pitch is reported to be negative the whole time ... impossible to travel backwards with a negative pitch (AC pitches nose down).

Your video confirms that this backwards movement didn't happen in reality ... the false movement path is marked in blue below, & the crash follows where the fat red cross is (the small red star is where the AC is just in that moment before the false movement, the green bar indicate the yaw direction).

View attachment 140876

Here the telemetry ...

All was good until 602,4sec (that's the AC position in above sat.picture) when the GPS level goes to 3 (red). At 602,7sec a false heading speed increases (black) & the velocity difference between the GPS & the IMU in a northerly & easterly direction goes heavily away from 0 mph, which is the normal (blue & purple). This clearly indicate an error either with the IMU or the GPS position. In this case it's obvious that it's the GPS position that's the fault... probably the bad GPS positional quality gives erroneous data to the IMU which it reacts on by trying to hold position ... but as the backwards movement is false the AC instead zip forward & crash. Strange that the IMU disregarded the gyro data which most probably showed no movement.

(Click on the chart to make it larger)
View attachment 140877

In the .TXT log message stream, below was shown at 603sec when the GPS level went to 3...

View attachment 140879
So this was unfortunately more of a pilot error, shielding the sky leading to erroneous GPS data ... DJI might take this as the the gyro also feed in data to the IMU (which should have been correct as no movement backwards was seen in your video) ... so the IMU made the wrong choice ... believing more in bad GPS data than the gyro data.

@slup Thank you for such a detailed analysis! I had no idea how much data got logged during a flight and it's really neat to be able to look at it all. When you say "DJI might take this as the gyro also feed in data to the IMU", do you mean DJI might accept this as a glitch rather than entirely pilot error? While I realize I should stay a bit further away from buildings, I'm having trouble coming to terms with the crashing being 100% pilot error...

 

[okw]

See comment above. And don't worry about being argumentative. It's all about helping everyone understand the rules and fly safe.

I read that comment and I understand the situational awareness aspect of flying. When I'm in an area that has the potential for manned flights approaching from any direction, I'm constantly aware of what's around.

But my house is on the side of a fairly steep hill. It would be impossible for a fixed-wing aircraft to fly just above the trees down the hill from behind me and still be able to pull up before getting to the next hill. And if the quad is staying below the trees in my front yard, even a rotary-wing aircraft wouldn't be in danger if it didn't drop between the trees into my yard.

Would that really still be an issue with VLOS?

And thanks for all of your replies.

 

[clintonamoar]

Ice is always a potential issue in the cold. If I suspect icing, I'll fly up about 50' and let it hover for a few minutes. Then I'll land and check the props. I'm in Colorado, so I fly in cold weather a lot! Definitely not irresponsible if done safely.

Ok, good to know!

It could cause that issue, but it shouldn't make it fly off like that. One thing I did notice in the video, although it's hard to know for sure, it looks like you may have inadvertently flown the drone into the window. It looks like you may have been pushing the right stick forward, and since the drone was facing you, it flew into the window. I can't tell for sure.

This is actually why I launch and land with the drone facing away from me. Always, and I have 100s of hours in the air, and 1000s of launches and landings. It's something I teach when I teach new pilots.

I was worried about that too at first, but checking the logs shows that I actually pull back on the stick right after it lurches forward. It seems that it completely ignored this command, or I input it too late.

I'll start launching and landing w/ the drone facing away from me then, thanks!

 

[Vic Moss]

I read that comment and I understand the situational awareness aspect of flying. When I'm in an area that has the potential for manned flights approaching from any direction, I'm constantly aware of what's around.

But my house is on the side of a fairly steep hill. It would be impossible for a fixed-wing aircraft to fly just above the trees down the hill from behind me and still be able to pull up before getting to the next hill. And if the quad is staying below the trees in my front yard, even a rotary-wing aircraft wouldn't be in danger if it didn't drop between the trees into my yard.

I understand that part, and do agree. But you may still have raptors and/or other drones. Highly unlikely in your situation, but still a thing.

There is the letter of the law, and the spirit of the law. Not something I'd worry too much about under the current flight, but it could be an issue in the future. You look pretty rural, there could be low flying aircraft in the summer.

Would that really still be an issue with VLOS?

And thanks for all of your replies.

 

[Deleted member 103366]

@Vic Moss what then is the situation for those that fly from inside a car? Not arguing, just curious.

 

[Clintoops]

Thank you for your detailed reply! Your guess is very reasonable, but incorrect. I have taken the TRUST this summer and did not print out the certificate when I did, but decided to re-take it just now. I acknowledge that I broke the VLOS rules, for which I take full responsibility, but I didn't see any mention of a rule that prohibits flying inside the home. As you could see, I had a large window in front of me, which allows for VLOS to be maintained during the whole flight, so long as I don't fly behind my house again like I did.

While I have only had this drone, the Mini 2, for 4 days, I have previous experience flying FPV racing quads with several hours in sims and several hours flying the actual thing. Not saying I'm an expert pilot, but I'm certainly not a first-timer either.

I also took a calculated risk flying in the cold, but I justified it because in all my previous flights, the battery never dipped below 69F (20.5C). As for ice accumulation, I decided to monitor how the AC was flying and if I noticed anything abnormal that I would bring the AC back immediately. Would you say those two decisions were poor judgement on my part?

I understand one of the reasons is if an aircraft. is in your area you wouldn't have seen it .
At which point we must land.
So it's things like that. Plus if a low flying see's your aircraft and reported no one was in attendance outside . It can be used to more regulate this hobby.
We don't need more black eyes.
Just a thought is all.

 

[Vic Moss]

@Vic Moss what then is the situation for those that fly from inside a car? Not arguing, just curious.

If you can fly with acceptable situational awareness, it's fine. I've done it when we needed to fly in an unpopulated area while my VO was driving. Perfectly legal.