Max altitude for effective flying?

[DKP]

Yesterday I was filming in the Rockies. I launched from approx. 10,000 feet ground altitude (very near tree line) and had very poor thrust response... Basically none.

I made two attempts and called it quits ( with hard landings).

I was using batteries with fresh charges that are less than 3 weeks old and only have 4 recharge cycles on them. The batteries preformed perfectly last week on a job at 2000 ft ground altitude.

I'm assuming the thin air at that Altitude is the issue, but can't find any information about performance expectations at high altitude.

Unfortunately I can't test at lower altitude for a few days.

Thanks

 

[itchybeard]

Were you using the DJI 9450 "thrust boosted" props?

If not then perhaps they would help you to achieve more lift in thin air.

Also, you might want to consider a T-Motor kit. It's more expensive than just changing the props, but they do produce more power, and if used in combination with the 9450 props they would probably solve the problem with room to spare. For more about the T-Motors see here ....

[youtube]http://www.youtube.com/watch?v=r2s3ed-BREw[/youtube]

 

[nhoover]

That's strange. I've launched from 10,000' once and didn't notice any problems like that. I've seen videos of flights at over 11,000'. I am going to Nepal next spring and will be flying from a pass at 17,600' (and of course many lower places first). Not a P2V+ but here's a flight to 13,700' http://www.flytrex.com/mission/quadcopt ... son-45845/

 

[N017RW]

Yea, I've seen a video of a P2 flying at Everest's base camp... 17,700 ft!

It appeared to fly fine...no word on flight time though.

 

[flyNfrank]

Really surprised nobody brought this up yet, but did you calibrate the compass prior to flight?

 

[N017RW]

How would that effect lift/thrust issues?

 

[John Shaw]

Yes, you will see performance drop with altitude and certainly at some altitude it can't sustain flight.
The old pilot saying is "high, hot and humid" - each of those adversely effect performance. So it isn't just altitude. If it is a warm day with high humidity it will be worse than on a cold, dry day. Also the weight of your Phantom makes a big difference, if you have added extra stuff the performance will do down. So be careful when comparing to other examples of performance.

 

[DKP]

Thanks.

I did not calibrate the compass and not sure why that would effect performance.

I don't have anything extra, just a gimbal and gopro.

I'll fly again ground altitude of 5400 on Sunday and compare.
This really is bothersome as we bought the phantom used with 4 batts. The batts had 50+ recharged on them and I found out quickly that the thing would just fall out of the sky at about 50-60% battery on all 4 batts.
That's why I purchased new batts (and replaced the gimble that broke as a result)

It behaved the same way on the high altitude launches (yet preformed perfectly last week with the same batts at a lower altitude)

It's always something

 

[Gautam Pandey]

That's strange. I've launched from 10,000' once and didn't notice any problems like that. I've seen videos of flights at over 11,000'. I am going to Nepal next spring and will be flying from a pass at 17,600' (and of course many lower places first). Not a P2V+ but here's a flight to 13,700' http://www.flytrex.com/mission/quadcopt ... son-45845/

I've had the exact same issue with a Phantom 2 - Stock props with H3 3d Gimbal and Gopro attached, So I should be within payload capacity.. took off at 10,000 ft and then uncontrolled descent and then hard landing. Felt like there want wasn't enough power/thrust. The battery was at 60%.

Went down to 8,900 ft.. same result with a battery at 60% It did perform a little better with a fully charged battery and I could have a controlled landing but didn't feel like good and I called it a day and packed up.

Could you share the specs of the Quad you were flying?

Thanks!!

 

[RoyVa]

Thanks.


This really is bothersome as we bought the phantom used with 4 batts. The batts had 50+ recharged on them and I found out quickly that the thing would just fall out of the sky at about 50-60% battery on all 4 batts.

It's always something

You say your would just drop out of the sky???? When mine get to low on the battery level it just self lands where ever it's at. Has happened to me twice when battery went to low during return flights. I have Ben able to use the find my phantom to drive and walk right up to it. Never had it just fall out of the sky!!!