If I fly 1000' below home point will RTH still work if connection lost?

[dgd3]

That was a good question. I have the same issue but for only going down 50 or 60 m below RTH.
When the RTH is activated would the phantom follow the same path back up the cliff that it took going down or would it rise straight up from where it was then fly over to home?
What action does the phantom take upon loss of GPS?

 

[dgd3]

What are some of the GPS location apps people are using? Are use iOS so I hope there are some for it.

 

[msinger]

When the RTH is activated would the phantom follow the same path back up the cliff that it took going down or would it rise straight up from where it was then fly over to home?

It'll ascend straight up until it reaches the RTH altitude.

What action does the phantom take upon loss of GPS?

It auto lands at its current location.

 

[skyeboysteve]

Does anyone know if the min flight altitude below takeoff is still around -1,800’ like it was for the P3P?

The reason I ask, is because I once had my P4P follow me down a pass that descended over 3,000 feet. I frequently updated its home point to my current location as I descended, but then it occurred to me what if I hadn’t hacked the max altitude limit; would I have even been able to land at my present location or would it have hovered at -1600’ till reaching critical battery level (which would prove disastrous)? Of course the same question applies to RTH, since updating home point to controller location doesn’t update launch altitude. Does anyone know if there is a negative limit to the P4P or did I get lucky; as the hack I used (I believe) only increased the positive altitude, not the negative.

 

[N017RW]

There is no negative altitude limit in the aircraft.

You may have experienced an app. limitation???

 

[skyeboysteve]

There is no negative altitude limit in the aircraft.

You may have experienced an app. limitation???

Good to know--I just remember reading there was a negative limit on the P3P--though I never tested it myself.

 

[Meta4]

What action does the phantom take upon loss of GPS?

The Phantom does nothing in particular when it loses GPS but without GPS it will be in atti mode.
Without GPS the Phantom loses the ability to hold position, brake and RTH.
It's still quite flyable and will respond to your control input but the flight characteristics will be different.
You can easily experiment to find out what this is like by flicking the flight mode switch to atti.

 

[68charger440]

The Phantom does nothing in particular when it loses GPS but without GPS it will be in atti mode.
Without GPS the Phantom loses the ability to hold position, brake and RTH.
It's still quite flyable and will respond to your control input but the flight characteristics will be different.
You can easily experiment to find out what this is like by flicking the flight mode switch to atti.

I recommend that everyone fly in ATTITUDE mode once they are comfortable in Position and Sport modes. It saved my bacon when I lost sat connections. I was able to fly home in windy conditions that had I not practiced in ATTITUDE mode many times before, I'm pretty sure I would not have been able to get it back home. Maybe some people could have learned on the fly on a windy day the first time, but they had better be quick learners and cool under pressure. The first time I flew in ATTITUDE mode on a windy day gave me a great deal of respect for how hard it can be. When things go right it is exhilarating, but when things go wrong it can be terryfying, and costly.

 

[jimlips]

I want to start my takeoff point at 11,000' altitude at ground level in the Colorado Rocky mountains, then fly roughly 1,000' down a cliff, and then back up taking stills and video along the way. If I have RTH altitude set at 45 meters and I lose contact with the P4 will it climb up the 1000' plus the 45 meter RTH altitude, and then land at the RTH point, or will being so far below ground level confuse it? Also, it might lose GPS when at the bottom.
Thx

There is an app I use on my Android-based smartphone called UAV Forecast that I love. It has saved me several times. It not only shows how many satellites will be in view at any given time, it shows a 24-hour forecast of what the conditions will be like, including predicted wind at 300', cloud obstructions, and the Kp value.

 

[N017RW]

Kp interference in sUAS flight is a myth.

Casts doubt on the efficacy of the app. as a whole.

 

[GadgetGuy]

Isn't the internal aircraft barometer (rather than the less accurate GPS) used for measuring elevation relative to the Home Point, for the preset RTH altitude?

If so, then loss of GPS and loss of signal will not prevent ascension to the selected RTH elevation above the Home Point, as the barometer is completely independent of signal and GPS. Assuming the RTH height is set high enough to restore signal, both signal and GPS should be restored by the ascension, and the lack of either at the time of RTH initiation becomes less important. ATTI drift during the vertical ascension is then the only concern, if the wind blows the aircraft into contact with any structures or hillsides.

 

[jimlips]

Kp interference in sUAS flight is a myth.

Casts doubt on the efficacy of the app. as a whole.

Rather than poo-pooing something, it would be better if you posted some facts. Kp interference in UAS flight is not a myth.

This webpage has a nice explanation about what Kp interference is, and how it can affect UAS flight:

K-Index FAQ

 

[GadgetGuy]

Rather than poo-pooing something, it would be better if you posted some facts. Kp interference in UAS flight is not a myth.

This webpage has a nice explanation about what Kp interference is, and how it can affect UAS flight:

K-Index FAQ

Just because you read it in a blog on the internet doesn't make it true...

 

[Meta4]

Kp interference in UAS flight is not a myth.

The next Phantom to be affected by flying during a high K-index event ... will be the first one.
So far there has been no effect on anyone's drone flying that could be connected to high K-index.
The likely actual impact would be a very small inaccuracy in GPS locations.
But as GPS has variable accuracy anyway, you probably wouldn't even notice it.

 

[Andy9]

I think flying in ATTI mode, more than lack of skills, is an orientation problem if the craft is not visible at that moment. In unknown environments a monitor picture might be misleading.
How is about compass data in GPS lost situation. Is there anything that helps you know which way the bird is heading to?
If you don't have a direct visual contact to the bird the flying back in ATTI mode can be very tricky if not even impossible.
If I am wrong I will be very happy.

 

[dgd3]

I think flying in ATTI mode, more than lack of skills, is an orientation problem if the craft is not visible at that moment. In unknown environments a monitor picture might be misleading.
How is about compass data in GPS lost situation. Is there anything that helps you know which way the bird is heading to?
If you don't have a direct visual contact to the bird the flying back in ATTI mode can be very tricky if not even impossible.
If I am wrong I will be very happy.

How do I get that graphic of the earth with satellite spinning around it? What program are you using for that?

 

[N017RW]

Google ‘GPS satellite orbit’ and you’ll get lots of choices.