Never fly without GPS satellites?

[MrRobville]

Just something that I was wondering. Say if I were at some extremely remote area where the Air is unable to connect to a sufficient amount of available GPS satellites (not sure if such area exists, but still) would takeoff always be out of the question?
I read in quite a few fly away topics that if you start flying without proper GPS locking that the drone can go haywire once it does connect midflight. Since you cannot force atti mode, I'm wondering if there's ever a case where it is safe to fly the drone without proper GPS, or if it's always a matter of "No GPS = No flight. Ever."

 

[Lake_Flyer]

No GPS is not a problem if you master Atti flying AND you're sure that GPS reception remains zero. If GPS mode kicks in and out randomly it will definitely become a challenge, also for experienced pilots.

If you're taking off without enough satellites you're asking for trouble. Only take off without GPS if you're sure it will remain in Atti during the whole flight.

 

[Lake_Flyer]

The lack of an Atti switch on MavicPro (and Air) is my biggest and only frustration about the mavic.

 

[msinger]

I read in quite a few fly away topics that if you start flying without proper GPS locking that the drone can go haywire once it does connect midflight.

I doubt it would go haywire. It should actually be more stable once it starts using GPS data to hold its position. Keep in mind the home point will be marked at its current location if it does require a good GPS connection mid-flight.

 

[Tinmania]

I read in quite a few fly away topics that if you start flying without proper GPS locking that the drone can go haywire once it does connect midflight.

In at least one case it was not just taking off without a good GPS lock: It was taking off with incorrect compass heading and inadequate GPS lock, compounded by lost signal. GPS kicked in but compass was still way off so when the FC tried to move the AC it moved it an incorrect heading, FC then tried even harder to fight what it presumably thought was wind and the AC flew far off in the wrong direction.

But that was a virtual smorgasbord of pilot error and compass error, and not really GPS. So if you deliberately choose to take off without GPS locked I would for danged sure make sure the actual orientation of the AC matches Go 4 or the RC. I would say it’s a good practice to check that even with a GPS lock.

All that said I wouldn’t normally fly without GPS and home point set.



Mike

 

[Travisimo]

DJI strongly recommends a pilot to land if the aircraft enters ATTI mode, and they also recommend avoiding flying in areas with weak GPS. That said, it's not necessary "unsafe" if you are educated on how to fly in these circumstances. As Mike said, it's absolutely imperative that you check compass heading, but obtaining GPS lock in mid-flight should not theoretically make your aircraft just fly away (it should become more stable, but you'd need to check for home point location and possibly reset it).

The downward vision system should help your aircraft's stability when at low altitudes (the manual states that it's effective up to 8m and anything higher can be affected). Importantly, you should NEVER fly out of line of sight without GPS lock (and even with it) because if you lost transmission, you'd have no way of flying home.

Personally, I would only fly without GPS at a very low altitude very close to me. There are some applications where this would be practical, but I certainly wouldn't just go flying up, up and away!

 

[MrRobville]

I appreciate all of the insight. The heading indicator on the map is a good one to keep in mind during any pre-flight check.
It makes sense to keep the quad close when only flying in atti. After all, there's no way in telling on where or when it doés receive GPS, especially when flying upward. At least it is good to know that as long as the compass is correct, a mid-flight GPS lock isn't that dangerous as I initially thought it to be, aside from the potential risky homepoint that could get set above an obstacle when it does.
So in general, you can fly without GPS, but only in very close proximity, making sure that anything you fly over is suitable as a potential home point in case the drone locks to GPS.

Though, I'm not planning on ever taking off without GPS, it's good to know that it is possible, should I ever find a nice shot in a poor GPS area.