Critical battery landing

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Well, today I had an incident with my Phantom 3 Pro. I have been flying this particular P3P for about 2 1/2 years now. But today it gave a little scare. I took off in the open desert with about a 92% battery charge. I then headed out on a long flight. I maneuvered around a bit and then went out about 5,000 feet while still show about 80% battery left. I flew around out there until the battery was down to about 40% and then hit the RTH button to let the drone come home on its own. I was up to about 100 feet in altitude as the drone set a direct course for home. I verified that the telemetry was showing a decreasing range, so I knew it was coming home okay. I decided to manually lower the altitude a little and went down to about 50 feet. About half way home I saw the "Low Battery" warning flash on the tablet, but I did not hear the verbal warning. A quick check of the monitor showed the drone at altitude and coming home. No need to hold the controller in my hands, so I set it down on my Quad and just waited for that familiar sound of bees coming at me. However, after a short time I realized that the drone should have been home by now. So I picked up the table and looked at the display. I was shocked at what I saw. Instead of bushes passing by below, I was looking at a still shot of bushes above the drone and flowers directly in front of the drone. It was on the ground!

Here is what happened. By mistake I had the volume turned all the way down on the Tablet and did not hear or see the "Critical Battery" warning. The battery had reached the 10% critical level and the drone landed on its own. Fortunately, I was recording the flight and I had the Prop guards on. It narrowly missed a bush when it landed still about 2,000 feet from home, but otherwise made a perfectly safe landing. I was able to follow the GPS tract on the Tablet and was able to quickly find and recover the drone without any trouble. I will be more careful next time. Below is the flight video of the whole incident from the Drone's point of view.

https://youtu.be/kW2MjKSpfOQ
 

ianzone

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Yahoo that's a close one
Didn't even stratch it ;), see clever batt knew you take off at 92 % and predicted it for you ,,I've had this happen at 1 & half miles out with other p4,,multiple attempts to cancel but got it back up in control,,scared the crap out me,turned out battery error and caused a fatal flight few flights after this happen,,now I'm always 100 on take off
 

JeffreyS

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That should not have happened. If you command a RTH before the craft decides to do it in it's own, then there should be enough power left to make it home. Other than saying something we already know, I have no further explanation. Once I was out over 12K feet and it executed a RTH with 58% remaining. Took nearly ten minutes to get back with about 10 or 12% left. Nerves were relieved.
 

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That should not have happened. If you command a RTH before the craft decides to do it in it's own, then there should be enough power left to make it home.
Actually, we've seen similar scenarios posted here many times. Normally the root cause ends up being going out with a tail wind and returning with a head wind. In this particular case, @Grandpa Don correctly did what most don't do - he descended to a lower, normally less windy altitude. So many times people have noted that they left their AC at a very high altitude for the very slow RTH trip and the wind is just too much. Aside from that, as has been noted here hundreds of times, starting with a less than fully charged battery can and often does create unreliable battery data which is extra bad when making these long distance runs.
 
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Explain please. Are you saying it's okay to fly 5,000 feet out? Can the drone be seen 5,000 feet out? How?
Your statement was ambiguous and misleading. The reason is not, because the drone won't make it back.
How about, if you can't see the drone, you can't see other aircraft that it might interfere with.
Not to condemn, but to help others understand.
 
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Semantics. Dig into the weeds if you want. Bottom like is: Flying beyond visual line of sight and not being in control of your aircraft ("set down the controller") are all in violation of FAA regs and totally against any common sense.
 
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Well, he said it was over the desert, not at some busy heavy traffic area. I don't like flying out of VLOS but sometimes you can not avoid this because the POI is more than 1km away and if you want to take picture or video it is the must. No obstacles between, flat land or over the water I can not see any problems. And if you fly not higher than 50m. Airplanes and other manned stuff should not fly so low. The rules are for them too I believe.
Besides I'm interested is the RTH the lowest battery consumption mode or it can be done better by manual? Because RTH is relatively slow and the most of the power drone uses for staying in the air not for going here and there.
 
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Besides I'm interested is the RTH the lowest battery consumption mode or it can be done better by manual? Because RTH is relatively slow and the most of the power drone uses for staying in the air not for going here and there.
lots of posts about this topic a few years ago but a few of them link to here it shows 15m/s is more efficient then 10m/s which is RTH speed. grandpa could have gotten further if he went manually faster than rth goes.
 

BigAl07

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@Grandpa Don we're glad you had a positive outcome as this one had all the ingredients for SEVERAL different conclusions.

I have to admit that you busted several rules with this one flight along with violated some "Best Practices".

  • A) Taking off on any long flight with a battery that isn't fully charged is a recipe for crash. The battery percentage is an ESTIMATE and the lower the % the higher your changes of it being off (Depending on how long it's been since a full charge cycle).
  • B) Flying BVLOS is asking for problems REGARDLESS where you're flying. We don't get to pick and chose when the rules apply to us.
  • C) Hitting RTH and laying the controller down... man that's all but assuring a problem is going to happen. You're in charge of that flight and everything that happens during it so it's wise to stay "on the controls" and at the very least pay attention to the display just in case. Even out in the desert we need to know where we are flying and be able to See & Avoid just in case. Don't be "That Guy".
  • D) When flying long distances you need to have a firm grasp on the wind both at lower levels and up where you're flying. Always TRY to depart with a head wind so hopefully you return with a tail wind.
  • E) Good move lowering the aircraft on RTH to possibly get better winds if it's going into a HEAD wind.

Thanks for sharing this story and hopefully many of us can learn from it going forward.

Allen
 
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That should not have happened. If you command a RTH before the craft decides to do it in it's own, then there should be enough power left to make it home. Other than saying something we already know, I have no further explanation. Once I was out over 12K feet and it executed a RTH with 58% remaining. Took nearly ten minutes to get back with about 10 or 12% left. Nerves were relieved.
You are correct. It shouldn't have happened. But I don't think it was a battery problem. Again...it was my fault for not paying attention. I knew I was pretty far out for the battery level. I was pushing it. Out here on the desert there are no trees or buildings to run into. Big bushes maybe! Just millions of places to land if necessary. I've done this before and I've landed it when I didn't think I was going to make it back. With my GPS tracking device I can go right out and retrieve it. The difference this time was that I did not hear or see the Low Battery warning, or the Critical Battery warning. I had set the controller down on my Quad and was just day-dreaming in the warm sun. It was my fault, not the battery. The whole point of my post was to tell pilots not to get complacent, or just assume everything is working according to plan. Watch that telemetry! If I would have notices the altitude decreasing I could have taken control and most likely forced it to stay up and landed where I wanted it to. To bad they don't have a "Whoop-Whoop- Pull-up" program in these things.
 
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That should not have happened. If you command a RTH before the craft decides to do it in it's own, then there should be enough power left to make it home. Other than saying something we already know, I have no further explanation. Once I was out over 12K feet and it executed a RTH with 58% remaining. Took nearly ten minutes to get back with about 10 or 12% left. Nerves were relieved.
No. If the AIRCRAFT decides to initiate RTH, THEN there should be enough battery power. If the operator initiates RTH, the bird is going to do what it was told, regardless.
 
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Well, he said it was over the desert, not at some busy heavy traffic area. I don't like flying out of VLOS but sometimes you can not avoid this because the POI is more than 1km away and if you want to take picture or video it is the must. No obstacles between, flat land or over the water I can not see any problems. And if you fly not higher than 50m. Airplanes and other manned stuff should not fly so low. The rules are for them too I believe.

Besides I'm interested is the RTH the lowest battery consumption mode or it can be done better by manual? Because RTH is relatively slow and the most of the power drone uses for staying in the air not for going here and there.


It sounds to me that you believe if you cannot fly a mission you want to fly because of the rules you think it's OK to break them. I don't think that's the way it works. It seems to me that many people think it's OK to break the law when the law doesn't suit them. I rather believe that if you cannot fly a mission without breaking the law it's a mission that should not be flown. People who break the law jeopardize all of us because it's an invitation for the authorities to create even more restrictive legislation. Am I wrong?
 
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JeffreyS

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No. If the AIRCRAFT decides to initiate RTH, THEN there should be enough battery power. If the operator initiates RTH, the bird is going to do what it was told, regardless.
No. If the aircraft makes the choice it is because there is just enough juice to get home. If the operator initiates the RTH (anytime before the aircraft might do it), there will be more than enough juice to get home. The exception would be if the operator overruled the low battery warning and then tried RTH some time after that.
 
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No. If the aircraft makes the choice it is because there is just enough juice to get home. If the operator initiates the RTH (anytime before the aircraft might do it), there will be more than enough juice to get home. The exception would be if the operator overruled the low battery warning and then tried RTH some time after that.
OK. LOL
 
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We all know this. But...the most important consideration when the RTH is initiated is the wind. The drone calculates the power needed to get back home in still air. If you are a considerable distance downwind you may not make it back. But if you are up wind you will most likely get home with power to spare. Many a drone has been lost due to not taking into account the wind speed and direction. Think Mavic Mini!
 
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We all know this. But...the most important consideration when the RTH is initiated is the wind. The drone calculates the power needed to get back home in still air. If you are a considerable distance downwind you may not make it back. But if you are up wind you will most likely get home with power to spare. Many a drone has been lost due to not taking into account the wind speed and direction. Think Mavic Mini!
Absolutelly agree. The wind is one of the most important factors for safe flying.
 

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