Flight with no GPS

[Sojourner60]

Yesterday I wanted to take some early morning fall photos just for fun. I started my P4 as I was walking to my front yard. I set it down, then started the motors. It took off fine, but then it hit a ceiling of about 50'. I've been flying this p4 for a couple of years and have run into this before. I let it hover for a few moments then it let me go on up to a higher altitude. I finished my flight and landed. When I checked my flight log in the DJI App it had a note beside it that said No GPS. I got to thinking about it and I never heard the "Home Point Updated" that I used to always hear at the beginning of a flight.

I didn't have enough battery to restart and try again.

Just curious if any of you have run into this before? What causes it and what's the fix?

I'll recharge my battery and try again this afternoon.

If you need more info, please ask.

Thanks in advance!
Donald

 

[PatR]

I don’t fly DJI all that often but isn’t 50’ the altitude cap present when the DJI EULA is rejected, or initial drone registration not performed?

 

[Sojourner60]

PatR,
I know that DJI will restrict hight and distance for, I want to say the first flight. I don't remember for sure what you have to do to get beyond those limits. Change settings comes to mind. After I hovered for a few seconds, it let me go ahead and fly higher and farther. But it never said Home Point Updated, or if it did, I missed it.

The question is why didn't my GPS connect. I didn't have any errors on the screen.

Donald

 

[PatR]

There are valid reasons GPS may not connect. An occluded signal is one of them.

GPS is not 100% reliable and can fail or degrade at any time. We have become accustomed to it working but we should always be prepared for when it doesn’t.

 

[R.Perry]

I'm wondering if you started your flight before locking on to GPS, I have noticed with mine sometimes if takes several seconds to lock the GPS location. I have also lost GPS during flights, I associated the loss with interference from high power routers but may very well be wrong. I have also lost GPS and then regained it. Very good reason to always keep your drone in sight.

 

[Imingui]

Got that issue a couple of times., Walt GPS to lock

 

[R Martin]

PatR,
I know that DJI will restrict hight and distance for, I want to say the first flight. I don't remember for sure what you have to do to get beyond those limits. Change settings comes to mind. After I hovered for a few seconds, it let me go ahead and fly higher and farther. But it never said Home Point Updated, or if it did, I missed it.

The question is why didn't my GPS connect. I didn't have any errors on the screen.

Donald

There are a number of reasons why the aircraft failed to lock up the GPS signal. Could have been location, satellite geometry, space weather (yes space weather), multipathing and a score of other factors. Guess that is something you need to add to your checklist...do I have a solid GPS lock and with how many satellites (4 is bare minimum I shouldn't launch anyway in GPS mode, 8 is marginal, 12+ is preferred).
If you do have problems getting a fix prior to launch, then that is the best indication that you are in the wrong spot and you should move (probably RF interference or multipathing errors). Not meaning to be a wet blanket, but there are places even with good satellite coverage and good GPS satellite visibility that GPS just will not work. Technology fails when you need it most.

 

[MedicFL1]

Might sound dumb but i flew my Phantom 4 the other day for battery maintenance reasons and encountered a similar problem. Turns out the App had put itself back into beginner mode. I had to come down and restart to convince myself all was okay.
That said, the Satellites that actually make up our US GPS system are being changed out by new ones with those SpaceX Falcon Heavy Flights off the Space Coast. Backwards compatibility is not supposed to be an issue as new channels are added - we'll see.

 

[R.Perry]

My goodness, how in the world did aviation function without GPS, or aircraft that fly themselves?

 

[BenMcCormick]

If I try to fly my Mavic Air without the phone, just the controller, I can't go further than 50'. I'm guessing its not the GPS, but the phone home to mother ship for permission thats the bottle neck. Otherwise, How would it know to stop at 50'?

 

[R Martin]

My goodness, how in the world did aviation function without GPS, or aircraft that fly themselves?

 

[LUIS MARTINEZ]

My goodness, how in the world did aviation function without GPS, or aircraft that fly themselves?

LOL. Easy. One hand on the stick, one eyeball on the magnetic compass and one finger on the folded sectional on the knee board. I can't believe anyone following an icon on an Ipad can call himself a pilot.

 

[R.Perry]

LOL, that is a great picture, just love it.

 

[Capt Binkley]

My goodness, how in the world did aviation function without GPS, or aircraft that fly themselves?

It's a shame how no one anymore has the enjoyment of dropping altitude and circling the water tower to find out where you are.

 

[R Martin]

It's a shame how no one anymore has the enjoyment of dropping altitude and circling the water tower to find out where you are.

Its a shame anyone had to do that to begin with. I always know where I am at any given point in space and time. I'm right here.