Any problems with compass around big ships?

[Andy9]

Have you ever had some compass issues close around big ships. A lot of metal should interfere with compass.

 

[dirkclod]

@Meta4 can tell you all about it as thats what I see he takes the most of and does so very good .

 

[msinger]

Have you ever had some compass issues close around big ships. A lot of metal should interfere with compass.

You'd have to be flying within several feet of those ships for them to affect the compass.

 

[Meta4]

Have you ever had some compass issues close around big ships. A lot of metal should interfere with compass.

If you are wanting to fly close enough to photograph small details on a ship, you might wake up the compass.
But if you are far enough away to photograph the whole ship rather than small parts of it, the compass won't give you any problems.

 

[horsepowerphoto]

I was going to land on the helipad of a passing ship (I had permission) but I was afraid that if I did land, the compass may screw up and prevent me from taking off again LOL

 

[Meta4]

I was going to land on the helipad of a passing ship (I had permission) but I was afraid that if I did land, the compass may screw up and prevent me from taking off again LOL

If the deck was steel that would have probably caused problems.

 

[Andy9]

I would switch to ATTI before landing.

 

[horsepowerphoto]

Ah crap... Good idea... Never even thought of it...

 

[Andy9]

Yes. But there is a big BUT. If no wind and the ship not moving, then is OK.
Otherwise you can have troubles as the drone won't hold the position. It will drift with the wind and this needs a lot of practice. You can try practicing in more coveniant place.
The same is if the ship is moving. And holding position is then of no use as the drone must move at the same speed and direction as the ship. It is very tricky buisnes. Suppose that that's why is not allowed to use a drone on ships.

 

[JMFinch]

After experiencing sudden repositioning when flying near a Wind tower DJI told me flying within 10 meters of that much metal can cause a crash.

You'd have to be flying within several feet of those ships for them to affect the compass.

 

[Meta4]

After experiencing sudden repositioning when flying near a Wind tower DJI told me flying within 10 meters of that much metal can cause a crash.

Did DJI investigate your flight data to confirm the cause of the incident or were they just guessing and making a general maybe comment?
Can you give any details of the "sudden repositioning" you encountered?
Was your drone at 10 metres or quite a bit closer than 10 metres.

 

[JMFinch]

I fly legally and the wind farm manager was present so i did not exceed 400' to center my Point of Interest (POI) over the wind tower
I was 10 feet from the edge of the tower climbing high enough to set the POI. Even though the right stick was still centered, my phantom quickly started flying toward the tower until i snapped it back with the right stick. I landed and tried it again with the very same results. I was successful about 15' from the tower. DJI support firmly said i need to stay back 10 metres though he offered no explanation. I once read on this forum that reflected GPS signals can cause a drone to fly to where it thinks its hold position is.

 

[Meta4]

I fly legally and the wind farm manager was present so i did not exceed 400' to center my Point of Interest (POI) over the wind tower
I was 10 feet from the edge of the tower climbing high enough to set the POI. Even though the right stick was still centered, my phantom quickly started flying toward the tower until i snapped it back with the right stick. I landed and tried it again with the very same results. I was successful about 15' from the tower. DJI support firmly said i need to stay back 10 metres though he offered no explanation. I once read on this forum that reflected GPS signals can cause a drone to fly to where it thinks its hold position is.

It sounds like the DJI support person was simply guessing and did not look into the specific incident.

Was this the first time you tried doing this sort of flight or have you done this successfully before?
It would be very interesting to look at the recorded flight data and perhaps work out what really happened.

If you want to do that ...
Go to DJI Flight Log Viewer | Phantom Help
Follow the instructions there to upload your flight record from your phone or tablet.
That will give you a detailed report of the flight.
Come back and post a link to the report it gives you.

 

[msinger]

After experiencing sudden repositioning when flying near a Wind tower DJI told me flying within 10 meters of that much metal can cause a crash.

10 meters would certainly keep you safe. However, you'd have to be much closer to the tower than that for it to negatively affect the compass.

If you want to test out that idea, hold your Phantom near the tower while it's powered on and see how close you need to be before the aircraft symbol starts rotating on the DJI GO map.

 

[Brojon]

You'd have to be flying within several feet of those ships for them to affect the compass.

I dunno - I've had my Mavic and Spark go nuts when approaching a building under construction - lots of metal I beams.

 

[Meta4]

I dunno - I've had my Mavic and Spark go nuts when approaching a building under construction - lots of metal I beams.

Lots of steel has no effect unless you are flying quite close to it.

 

[Brojon]

That's still pretty far away. How about closer in?
Mind you I'm mostly in agreement since avionics and nav systems would be at risk if it was a big deal.

 

[Meta4]

That's still pretty far away. How about closer in?

There's about 50000 tons of steel there but no compass issues at that distance.
You'd have to get closer than 20 feet to see any problems.

 

[solentlife]

There's about 50000 tons of steel there but no compass issues at that distance.
You'd have to get closer than 20 feet to see any problems.

mmmmm She's actually only about 12,800 MT Summer DWT ... giving her only a fraction of your 50KT in actual light displacement. (GRT and NRT are not actual weights but volumes)

 

[Meta4]

mmmmm She's actually only about 12,800 MT Summer DWT ... giving her only a fraction of your 50KT in actual light displacement. (GRT and NRT are not actual weights but volumes)

I made a very rough estimate because I was unable to find the displacement anywhere.
But deadweight is not the weight of the ship either.
You might benefit from this reference: Deadweight tonnage - Wikipedia