Will Pixhawk survive 200ft drop? and failsafe assistance needed

Anyone know if a 200ft drop into sand will damage any sensors in the Pixhawk 2.1 or Here gps? Should I replace them to be safe?

I was testing failsafe and flipped off the controller and the drone stayed put with red and yellow lights flashing, never tried landing. I verified it enters RTL on the ground prior to the flight. Anyone know why? RTL works great when I enter it manually.

The .bin file is 3402 KB. When I use the upload button, it says it’s too big and must be less than 4500 KB…

here’s the log on dropbox

A crash won’t damage the sensors. They are rated for some ting crazy like10,000 g, so the board would be broken before the sensors.
I will look at your log. Did you set up you receiver throttle failsafe?

I looked at your log. Most of your flight was in Auto mode, but your throttle stick was down.
It went into Stabilize mode for a second or so before going into RTL mode. I would have thought I would recover, but I guess it was falling to fast.
Root cause: Going into Stabilize mode with throttle down. Why it went into Stab mode is the question. Check your receiver failsafe settings on MP. Go to the radio calibration and monitor the what your receiver is doing when you turn of the Tx.

Yea the why it crashed was my own stupidity. What happened was after I turned the controller back on after the failed RTL, by habit I listened to the “throttle warning” and put it at zero without even knowing I did it (was 5am) and still didn’t know I had done that until I was walking into the house for a flashlight after the crash and trying to figure out what just happened. I felt pretty stupid. When the copter went silent at 200ft, I immediately switched to RTL not knowing what was going on and RTL did nothing but level the copter as it plummeted because I have the RTL setting toggled that lets me control the craft during RTL (sorry can’t look up the setting name atm). So because throttle was 0%, it was hitting the ground even in RTL. It has the power to save itself from such a fall.

Haven’t been able to mess with it since to figure out why it does nothing but hold position when signal is lost. Irma’s eye passed 3 miles west of me and I’m still without power.

The receiver cuts all signal to the pixhawk with signal loss.

Actually in this particular flight, the failsafe is set to reduce throttle below minimum. Was trying that since no signal wasn’t working. Both ways gave same results.

I spent some time going over your log in greater detail. Looks like you took of in STABILIZE mode and switched to AUTO.
You shut off your Tx a few times and it continued on its mission. The reason it continued on was that’s how the failsafe was set up. You can get all the parameters from a DF log. The param FS_THR_ENABLE is set to 2, which means “continue with auto mission when in radio failsafe”. If you sett that param to 1 it will RTL on throttle failsafe. They ke here is you were in AUTO mode, any other mode it would RTL.
The third time you switched off the Tx The mission had ended and it just loitered were it was. At some time while the TX was off you lowered the throttle, which was at hover, where you left it, for most of the flight. You must have switched to STABALIZE also during this time and when the RC system came back to life, you know what happened. Don’t feel bad most every one has done this at least once.

The time from STAB mode to impact was 4.2 sec. I got this from accelerometer and other data. That’s about right as you were at 60 m alt and it was getting closer to terminal velocity. I remained almost level which is just luck I guess, they usually tumble.

I am wandering about your flight modes you seem to have set up. I didn’t see RTL so maybe there was a log error ? What I saw in your params was: 1 ACRO, 2 STAB, 3 POS_HOLD, 4 BREAK, 5 AUTO, 6 AUTO. You must have selected RTL from a GCS ?

The other mystery is the fact that the throttle did rev up, not from the Tx, but from RTL mode. This happened 1.0 sec. from impact. Problem is this was 3.9 sec after it knew it was in RTL mode. Does this fit with your recollection ?

I don’t know how your Tx modes work. Did you have to switch through STAB to get to RTL ? You may have found a possible bug in this particular case.

Yea I’m only concerned with the last waypoint when it holds position with yellow and red flashing on the Here gps.

That 4.2 seconds felt like 2 hours. I switched to RTL immediately when it went silent, but RTL didn’t kick in until halfway down and spun the motors just enough to level it because throttle was at 0. You can see this in GPS altitude data. There is a clear point around 100ft when RTL started the motors and descent rate slowed and stabilized. RCOut corroborates.

I must have selected stabilize to test lost connection from that mode, but never made it that far.

RTL is on my channel 7 (flight modes channel 5).

When I can test it doesn’t work in stabilize or brake also, I’ll update the thread. In that case, it’s probably a problem in my setup, otherwise it’s a bug from auto.

just fyi, it is illegal to fly recreationally in a disaster area… this flight was before the hurricane

Hey Kieth,

Sorry about that. I just assumed it was a more recent log. MP flight data screen went to your location and I zoomed out to see where you were, and MP showed a purple border over south Fl. That’s what made me think of it. I should have looked at how old your post was…doh!
The channel 7 switch… I forgot about the switches. That explanes all except the delayed RTL throttle response. It should have save it’s self despite the human trying to crash it… :slight_smile:
I will try to get the devs attention about this matter. RTL from a switch should be instant. From radio/throttle fail safe I think there is a delay of a few seconds. BTW I edited my last post.

well as I said, LAND_REPOSITION is set to 1, so RTL cannot save anything with throttle at 0

Hello ikieth, I can assure you about RTL land/rtl repositioning, I also have LAND_REPOSITION set to 1 and have used it many times. After a long fpv flight with light getting low I sometimes get lazy and hit RTL. Then I reposition close to landing so I don’t have to walk as far ;). This is always under auto altitude control. Doesn’t matter where the throttle is (I have mine down). And in your case it did rev up just before impact, not soon enough and a few second after you hit the switch. You shouldn’t have crashed.

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ok ill take your word for it… ill have to test that also when I’m back flying, thx for your help