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My first Fly-Away... was it me or the H?? Help (flight log attached)

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Can you upload a picture of the marks on the GPS? It might help answer the question of why three control related parameters changed between two flights that seem seperated by only 5 minutes and a battery change.

Did anything other than a battery change happen between the two flights?
i will get you pictures of that.... I removed the real sense module at my car either before this flight or before the flight that I plotted the CCC waypoints
 
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The waypoints were not the problem, a flyaway occurs when the instruments (GPS and Compass) used for positioning do not agree. You had not started a CC Mission so those way points were not a consideration in this crash
I guess i was trying to see if telemetry was incorrect. after further review, are you stating that it looks like the gps locations now add up and are correct (prior post mentioned account matches up with telemetry)??
 

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I plotted like 16 way points for CCC just before this takeoff. The waypoints should all be around the subject house and not in neighboring yards. is it possible to see if those way points plotted correctly ?
I don't know how to extract the waypoints, but here is the flight path of the flight prior to the crash flight if it will help:

google 352.JPG
 

Ty Pilot

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I guess i was trying to see if telemetry was incorrect. after further review, are you stating that it looks like the gps locations now add up and are correct (prior post mentioned account matches up with telemetry)??


Telemetry is usually correct. In some cases when we are told from the pilot's view of what happened, it does not match the telemetry. This is due to the fact that when a pilot is faced with an unfolding situation such as an imminent crash; their recall of of those circumstances can be degraded.

What I am seeing (and this is just one man's opinion) assuming this was a fully (and correctly) functioning Typhoon H, the location selected for takeoff caused an errant compass setting that; once in the air, conflicted with the GPS signals and caused a classic 'fly-away'

You may have taken off there many times with no problem but on this occasion it could have been the reason for the fly away. I've had it happen to me flying my 480 many years ago.
 
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Can you upload a picture of the marks on the GPS? It might help answer the question of why three control related parameters changed between two flights that seem seperated by only 5 minutes and a battery change.

Did anything other than a battery change happen between the two flights?
First two pictures is module just removed from drone (scratches are from my thumbnail). This module had was silver when installed 2 months ago. SECOND picture is the module I removed when I was having compass issues before. Notice it has marks on it as well.

EDIT : sorry.. that was confusing... first two are of module pulled from subject H after crash. This module was installed 2 months ago and had no marks on it at all (just silver). I was replacing the module in the 3rd picture because i was having compass issues. I noticed that module had similar marks when I replaced it.

gps module new failed 2.jpg
gps module picture new failed.jpg

OLD ONE BELOW

GPS module picture old.jpg
 
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Telemetry is usually correct. In some cases when we are told from the pilot's view of what happened, it does not match the telemetry. This is due to the fact that when a pilot is faced with an unfolding situation such as an imminent crash; their recall of of those circumstances can be degraded.

What I am seeing (and this is just one man's opinion) assuming this was a fully (and correctly) functioning Typhoon H, the location selected for takeoff caused an errant compass setting that; once in the air, conflicted with the GPS signals and caused a classic 'fly-away'

You may have taken off there many times with no problem but on this occasion it could have been the reason for the fly away. I've had it happen to me flying my 480 many years ago.
Would my real-sense module (if installed and activated) have helped to control the H from "taking off" after GPS/Compass error?
 

WTFDproject

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first two are of module pulled from subject H after crash. This module was installed 2 months ago and had no marks on it at all (just silver). I was replacing the module in the 3rd picture because i was having compass issues. I noticed that module had similar marks when I replaced it.

Those are actually the GPS antenna part of the GPS module.
It's hard to tell from the pictures, but if those are burn marks on two GPS antennae, and both occurred from the same drone, it raises some serious concerns that something is going on with that mainboard.

I assume the damage was a bit above casual. Are you planning on doing a rebuild that would include this mainboard?
 

Fred Garvin

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...The waypoints were not the problem, a flyaway occurs when the instruments (GPS and Compass) used for positioning do not agree...

So, the system is not "Fail-Safe"....in that when something like this disagreement happens, rather than just hovering in place, the drone will randomly take off at full throttle in some direction?
 

WTFDproject

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Would my real-sense module (if installed and activated) have helped to control the H from "taking off" after GPS/Compass error?
The drone was travelling ~22.5 MPH just prior to impact. I doubt Real sense could have completely stopped that in time.
However, if the Realsense was fully functioning and limiting total speed to ~11.2 MPH, that might have prevented the actual impact.
 
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First two pictures is module just removed from drone (scratches are from my thumbnail).
Normally, siver tarnishing when it come in contact with air. The sulfide is there where the duct tape was removed. No incident. But the previous problems with different GPS modules let think about the mainboard/MCU board. Something maybe wrong there at all.
What let me doubt:
1) Never saw such big difference between telemetry data and reality, even after crash.
A crash is seen at 12:17:00.726 in pitch/roll/yaw. The pos according coordinates and GoogleMaps was here:
pos1_crash.jpg
At 12:17:01.775 (1s later) Motor 4 off (5-Rotor mode?). And position is that:
pos2_motor4.jpg
At 12:17:01.926 (only 150ms later) last data set before emergency shutdown her:
pos3_after_shutdown.jpg
Next data set is 6s later at 12:17:07.864. Position is now here:
pos4_before_shutdown.jpg
In those 6s everything could happen, but we already lost 1 motor. I think in this gap all the things you described take place (#8). No recording at all. All the time comoass errors that ends with emergency shutdown. GPS accuracy went bad after motor 4 was cut. That's explainable because drone is rotation GPS antenne away from the sky. Also 2.4GHz RC connection got poor.

At 12:17:10:324 the Position shows up here:
pos5_away.jpg
Hmm, without running motors? Never ever!

2) With ST16 firmware B25 feature "Dual band Control Redundacy" was introduced. Telemetry (an commands) will be sent either via 2.4GHz ZigBee connection or via 5GHz WiFi from camera hotspot. In the last flight 00353 we see a strange behaviour of the switch of telemetry between 2.4GHz and 5GHz. I never saw such a low and short amout of data from 5GHz. See picture [email protected]:
2 flights.jpg
3) Massive amount of compass calibration warnings during nearly the whole flightlasting over ~22s without interuption. This is also unusual. This may be the main cause of the fly-away.

br HE
 
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Anyway I too a quick look and the GPS coordinates in the CSV file don't line up with your map. The crash site coordinates are good but the flight coordinates don't look right to me. Facing the house the GPS coordinates have the H on the right side of the house going around from right to left crashing into the house extension.
 

DoomMeister

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Anyway I too a quick look and the GPS coordinates in the CSV file don't line up with your map. The crash site coordinates are good but the flight coordinates don't look right to me. Facing the house the GPS coordinates have the H on the right side of the house going around from right to left crashing into the house extension.
What are you using to analyze the flight data? Where do you consider the impact to have taken place?

Just curious how you arrive at your decision.
 
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Those are actually the GPS antenna part of the GPS module.
It's hard to tell from the pictures, but if those are burn marks on two GPS antennae, and both occurred from the same drone, it raises some serious concerns that something is going on with that mainboard.

I assume the damage was a bit above casual. Are you planning on doing a rebuild that would include this mainboard?
yeah, no subframe damage... just need to replace top and bottom shell, 4 new arms , and I have 2 cameras that I rotate when one gets damaged and send broken one out to get repaired at a really good price. Parts arrive tomorrow and I’ll be able to see how it functions.
I have a secondary H I was using until it had subframe damage from a crash at beginning of the year (??‍♂️operator error on that crash). Do you suggest me start rebuilding that one if I continue to get compass and GPS errors?
 

WTFDproject

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I believe all are in agreement the crash was due to a compass error resulting in GPS errors. The remaining discussions involve what caused the compass error.
In all, there are 4 major anomalies in this flight:
1.) Compass error of unusual duration.
2.) GPS errors, in two stages.
3.) 5.8 Ghz backup RC control signal swap frequency.
4.) Drone response to manual control. (Controller was transmitting normally)

Several explanations have been proposed. Items that include rebar in the concrete, the gates, other flight environment factors, and a problem with the FC on the main board. Of these, I don't know there is a way to conclusively prove or conclusively disprove any. The two proposals best supported by history are the rebar theory, and the problem flight control board.
I think the "burn" marks on the GPS antenna are no longer considered an issue. Similar marks are seen with normal oxidation, and there does not seem to be a plausible circuit that could have shorted to the antenna without other damage being noted.
I don't think you had time between the flights to remove the Realsense module, so currently dismiss that as a difference in the flights. I currently assume you removed Realsense prior to the first flight.
I don't think the second battery was the issue. Voltage was good, and voltage trace looks pretty normal for the events.

My recommendation? Change the FC Board as the "common factor". (All four of the main anomalies are functions processed by the FC Board.)
Repair the bird, and do a few tethered test flights in a safe area. Upload the flight logs from the test flights so we can look for any of the same anomalies that showed up on this one.
 
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I believe all are in agreement the crash was due to a compass error resulting in GPS errors. The remaining discussions involve what caused the compass error.
In all, there are 4 major anomalies in this flight:
1.) Compass error of unusual duration.
2.) GPS errors, in two stages.
3.) 5.8 Ghz backup RC control signal swap frequency.
4.) Drone response to manual control. (Controller was transmitting normally)

Several explanations have been proposed. Items that include rebar in the concrete, the gates, other flight environment factors, and a problem with the FC on the main board. Of these, I don't know there is a way to conclusively prove or conclusively disprove any. The two proposals best supported by history are the rebar theory, and the problem flight control board.
I think the "burn" marks on the GPS antenna are no longer considered an issue. Similar marks are seen with normal oxidation, and there does not seem to be a plausible circuit that could have shorted to the antenna without other damage being noted. (The antenna itself is not a "powered" component.)
I don't think you had time between the flights to remove the Realsense module, so currently dismiss that as a difference in the flights. I think you removed Realsense prior to the first flight.
I don't think the second battery was the issue. Voltage was good, and voltage trace looks pretty normal for the events.
My recommendation? Change the FC Board as the "common factor". (All four of the main anomalies are functions processed by the FC Board.)
Then repair the bird, and do a few test flights in a safe area. Upload the flight logs from the test flights so we can look for any of the same anomalies that showed up on this one.
Would FC Board be the entire main circuit Board (that all the arms connect too, etc)
 

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