Height Limit of 30 feet and 98 feet in Center City Philadelphia

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I am a pilot with a 107 license.

Yesterday I was flying an assignment in Center City Philadelphia.
This is in an area of the city that is not part of LANCC.
At some points the height of my Phantom 4 Pro was limited to 30 feet.
Other times it was allowed to go to 98 feet.
It was very arbitrary when these limits were imposed.

I have the DJI Go 4 app set to a height limit of 400 feet.

I tried the Litchi app and on the first flight it allowed the drone to fly up to 98 feet.
A subsequent Litchi flight limited the height to 30 feet.

Does anyone have advice on how to make sure I can at least fly 98 feet high if not higher?
 
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Meta4

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Yesterday I was flying an assignment in Center City Philadelphia.
At some points the height of my Phantom 4 Pro was limited to 30 feet.
Other times it was allowed to go to 98 feet.

Does anyone have advice on how to make sure I can at least fly 98 feet high if not higher?
The heights you mention make me wonder if you might have had poor GPS reception.
Were you in an urban canyon environment with a significant part of the sky blocked by tall buildings?

This section of the manual might be a clue for you:
Height is restricted to 26 feet (8 meters) when the GPS signal is weak and Vision Positioning is activated.
Height is restricted to 98 feet (30 meters) when the GPS signal is weak and Vision Positioning is inactivated.
Your flight data would confirm if this was the reason for the height limits.

If you have insufficient sats for P-GPS mode, disable your VPS sensors and you'll be able to fly to 98 ft.
Otherwise, ensure you have good GPS reception and you can fly higher.
 
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I am a pilot with a 107 license.

Yesterday I was flying an assignment in Center City Philadelphia.
This is in an area of the city that is not part of LANCC.
At some points the height of my Phantom 4 Pro was limited to 30 feet.
Other times it was allowed to go to 98 feet.
It was very arbitrary when these limits were imposed.

I have the DJI Go 4 app set to a height limit of 400 feet.

I tried the Litchi app and on the first flight it allowed the drone to fly up to 98 feet.
A subsequent Litchi flight limited the height to 30 feet.

Does anyone have advice on how to make sure I can at least fly 98 feet high if not higher?
I fly in Center City all the time and have never run into any such limitations. Basically all of Center City is outside of the PHL Class B due to a carve-out up to 1500 feet. This is not new and I have never had any issues with DJI Go 4. The last time I flew in the area was just about two weeks ago with no issues with either altitude or distance.

As @Meta4 mentioned above, this seems to be more an issue with your craft and GPS coverage, due to the very specific numbers you mentioned. Also if it were due to airspace restrictions in the Go4 app, then the messages would have been very clear as to why those restrictions were there.

If you have your flight logs, they should confirm all of this.
 
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The heights you mention make me wonder if you might have had poor GPS reception.
Were you in an urban canyon environment with a significant part of the sky blocked by tall buildings?

This section of the manual might be a clue for you:
Height is restricted to 26 feet (8 meters) when the GPS signal is weak and Vision Positioning is activated.
Height is restricted to 98 feet (30 meters) when the GPS signal is weak and Vision Positioning is inactivated.
Your flight data would confirm if this was the reason for the height limits.

If you have insufficient sats for P-GPS mode, disable your VPS sensors and you'll be able to fly to 98 ft.
Otherwise, ensure you have good GPS reception and you can fly higher.
This makes sense. I was flying in a canyon environment, where the GPS signal was weak. I'll try turning off the visual sensors to gain more height.
 
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When I have been in that position in real canyons, I flew up to a point without GPS, till I had good GPS. I then turned the GPS on. It was about 150 feet when I got good GPS, just above the tree tops. I understand that may not work for you, but in some situations where you need a higher altitude it can help.
 
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I've had a similar situation a couple of times. One was because I turned on the drone in the bed of a truck. Even though I picked it up and moved it to take off, it limited me to 100 ft. Even turning it off and back on didn't fix it. It wouldn't let me fly higher or further than 100 ft. I think I had to recalibrate the compass to fix the problem.

The second occurrence was in downtown Los Angeles. And yes, downtowns suck for flying. So much interference, GPS blockage and who knows what kind of metal under the street? More than once I was limited in height to something like 50 ft and no amount of powering off and on or recalibrating helped me (in that spot).

The only time I've had a flyaway (which quickly resulted in a crash) was in a downtown environment because the drone didn't like what was under the sidewalk. At first there was compass error and then it went away. I took off, flew up 30 feet and then the drone went straight into a building on its own.

I've read that other professional companies fly in Atti mode in downtown environments to avoid such problems. They also have one or more VOs since the margin for error in those canyons is very small.
 

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