What could cause a P4P to overfly the RTH point?

[Ripper7620]

RTH, in combination with Autoland, acts differently. RTH by default is set speed of roughly 20mph, and with OA turned on, will not exceed 30mph at full throttle. As soon as Autoland kicks in, OA gets turned off, and your full throttle speed becomes close to 40mph. I usually am already in Autoland when landing at less than 10% remaining battery, and, unless I reduce the throttle, I will overshoot my Home Point, too! Be safe, and learn how these festures work together. It isn't always as you would expect.

I always back off the throttle as it approaches the RTH point, and it automatically reduces the throttle as it approaches the RTH point. When it starts to autoland, I just let it do it's thing.

 

[GadgetGuy]

I always back off the throttle as it approaches the RTH point, and it automatically reduces the throttle as it approaches the RTH point. When it starts to autoland, I just let it do it's thing.

Maybe I am incorrectly projecting my scenarios onto yours. My aircraft usually enters Autoland at 10% remaining when I am anywhere from a half a mile to a mile away. I can't just let it do its thing. I still have have to safely navigate it back to me under all the above described Autoland parameters.

 

[Ripper7620]

Maybe I am incorrectly projecting my scenarios onto yours. My aircraft usually enters Autoland at 10% remaining when I am anywhere from a half a mile to a mile away. I can't just let it do its thing. I still have have to safely navigate it back to me under all the above described Autoland parameters.

I was under the impression that once the battery got that low, and started an autoland procedure, that the pilot no longer had enough control over the AC to get it back to the original launching point. I would love to hear how you guide it back on 10% battery, because that's certainly above my pay grade at this point. Thank you in advance.

 

[msinger]

I was under the impression that once the battery got that low, and started an autoland procedure, that the pilot no longer had enough control over the AC to get it back to the original launching point.

If the battery reaches the critically low level and the Phantom starts to auto land, you can:

1) Let go of the remote controller sticks and let the Phantom land at its current location.

2) Steer the Phantom to a safer landing spot while it's descending to land.

3) Hold the throttle in the full up position (to prevent the Phantom from descending) and steer it to a safer landing spot. Once you're at a safe location, let go of the throttle stick so the Phantom can finish landing. Keep in mind that the battery will eventually shut off mid-flight if you keep the Phantom in the air too long.

 

[Ripper7620]

If the battery reaches the critically low level and the Phantom starts to auto land, you can:

1) Let go of the remote controller sticks and let the Phantom land at its current location.

2) Steer the Phantom to a safer landing spot while it's descending to land.

3) Hold the throttle in the full up position (to prevent the Phantom from descending) and steer it to a safer landing spot. Once you're at a safe location, let go of the throttle stick so the Phantom can finish landing. Keep in mind that the battery will eventually shut off mid-flight if you keep the Phantom in the air too long.

Thank you very much, knowing that could have prevented my crash, along with the other mistakes I made.

 

[GadgetGuy]

If the battery reaches the critically low level and the Phantom starts to auto land, you can:

1) Let go of the remote controller sticks and let the Phantom land at its current location.

2) Steer the Phantom to a safer landing spot while it's descending to land.

3) Hold the throttle in the full up position (to prevent the Phantom from descending) and steer it to a safer landing spot. Once you're at a safe location, let go of the throttle stick so the Phantom can finish landing. Keep in mind that the battery will eventually shut off mid-flight if you keep the Phantom in the air too long.

You can also CANCEL Autoland (never tried, but have seen the option!) and you can still ASCEND during Autoland with full left up throttle. It is a much reduced ascension rate, but it is not just a mere hover! Try it! Best to first get to the elevation you need to clear all obstacles during the last 10% while flying back, or above it, as I have found that the reported elevation is often higher than actual (failure to let barometer stabilize completely before takeoff to conserve battery), and I want to land it on a straight glide path, from which I can actually see it above my eye level from a distance, but not overshoot and not be up too high where it takes too long to get down, before reaching 0%. My goal is 5-9% remaining, which leaves a margin of error. OA will be turned off automatically during Autoland, so no obstacle avoidance, and forward speed will exceed 30mph in full throttle, so back off the throttle to maintain 30mph, and then glide her in! 0% will not cause the battery to shutoff until one cell reaches 2.99V. At 0%, all four cells are still above 3.5 volts on a healthy battery!

 

[Ripper7620]

You can also CANCEL Autoland (never tried, but have seen the option!) and you can still ASCEND during Autoland with full left up throttle. It is a much reduced ascension rate, but it is not just a mere hover! Try it! Best to first get to the elevation you need to clear all obstacles during the last 10% while flying back, or above it, as I have found that the reported elevation is often higher than actual (failure to let barometer stabilize completely before takeoff to conserve battery), and I want to land it on a straight glide path, from which I can actually see it above my eye level from a distance, but not overshoot and not be up too high where it takes too long to get down, before reaching 0%. My goal is 5-9% remaining, which leaves a margin of error. OA will be turned off automatically during Autoland, so no obstacle avoidance, and forward speed will exceed 30mph in full throttle, so back off the throttle to maintain 30mph, and then glide her in! 0% will not cause the battery to shutoff until one cell reaches 2.99V. At 0%, all four cells are still above 3.5 volts on a healthy battery! View attachment 100490

Thank you very much for the information, but I need some skills before can tackle all that. However, I have noticed that I have to push the envelope in order to improve at any kind of meaningful rate.

 

[GadgetGuy]

Thank you very much for the information, but I need some skills before can tackle all that. However, I have noticed that I have to push the envelope in order to improve at any kind of meaningful rate.

Not for the faint of heart, but critical to know there is still full control, when everyone thinks that there is none, once Autoland starts. All long distance flyers eventually learn this the hard way, me included! No more panic. Just get her down within reach and grab a skid!

 

[TrevorTron]

Not for the faint of heart, but critical to know there is still full control, when everyone thinks that there is none, once Autoland starts. All long distance flyers eventually learn this the hard way, me included! No more panic. Just get her down within reach and grab a skid!

This is indeed very helpful info, I did not know about the 0% vs 2.99V = really empty!
Panic does set in and can cause rash decisions. I have a fight with a friend's P3 Pro recently. He's asked me to sort a bad tilted horizon issue. Having set the pot straight again, it had to go for a test fly of course but unbeknown to me he'd set battery 'critical' to 30%. I was bringing her in when auto-land kicked in and she was trying to land just off the edge of the balcony where I was standing. It was quite a fight just to keep her airborne, stable and 'catchable'. A situation where three hands (2 on the controls & one to catch since she wouldn't hover) would have been useful. Happily all ended well with bird, all props & fingers intact.