Question about a multiple battery flight

[Forby]

I'm flying a very large tract of land of about 1 mile long and 1/3 mile wide. I may not get permission to center myself on the site. There is a highway along one side, so I thought I might start at one end and walk the long end as I fly while having a safety car following. I know I need three batteries and I am concerned that if I start to land downstream of my starting point and the battery goes too low, will the drone attempt to return to it's original starting point while I'm landing it.

I'm not sure how the algorithm work. I'm using PIX4D and Phantom 4.

Any ideas? I can short cycle the flights and land at 30%, but I may not have enough total battery time if I do that.

 

[jkerrins]

How about setting RTH to current location? Sounds like quite a bit of risk mitigation to work out. Good luck.

 

[Forby]

Will DJI RTH overide Pix4D return to launch point?

 

[PhilZ]

I can’t answer your question directly, but perhaps you could try that under a closely flown test map? Another possibility is to set up the map so it flies in the 1/3 mile direction, so you get a more efficient flight pattern. If it takes 20% battery to fly the 1 mile leg, you pretty much have to bring it home around 40% because you can’t start another leg unless you will land close.
I have flown many maps with DroneDeploy and can say you will need more batteries than you think. Tuesday I flew a 122 acre parcel where the farthest distance was 3400’ away. An Inspire 2 has about the same flight time as a Phantom 4. We used seven sets of batteries on a high overlap map.

 

[licensed pilot]

I'm flying a very large tract of land of about 1 mile long and 1/3 mile wide. I may not get permission to center myself on the site. There is a highway along one side, so I thought I might start at one end and walk the long end as I fly while having a safety car following. I know I need three batteries and I am concerned that if I start to land downstream of my starting point and the battery goes too low, will the drone attempt to return to it's original starting point while I'm landing it.

I'm not sure how the algorithm work. I'm using PIX4D and Phantom 4.

Any ideas? I can short cycle the flights and land at 30%, but I may not have enough total battery time if I do that.

Why are you restricted as to your launch point?

 

[Forby]

I can’t answer your question directly, but perhaps you could try that under a closely flown test map? Another possibility is to set up the map so it flies in the 1/3 mile direction, so you get a more efficient flight pattern. If it takes 20% battery to fly the 1 mile leg, you pretty much have to bring it home around 40% because you can’t start another leg unless you will land close.
I have flown many maps with DroneDeploy and can say you will need more batteries than you think. Tuesday I flew a 122 acre parcel where the farthest distance was 3400’ away. An Inspire 2 has about the same flight time as a Phantom 4. We used seven sets of batteries on a high overlap map.

I'm flying the most efficient route. My concern is the wasted time flying out to the starting point and back to change batteries. I was hoping to make things more efficient by walking the long leg as the drone flies.......

 

[Forby]

Why are you restricted as to your launch point?

We are fling an industrial area being developed by a private concern. They own the roads in the park. We are flying for an authority that imposes a fee for stormwater runoff. The fee is per year and is over 200K! THEY DON'T WANT US THERE!!!!!!!!

I'd love to be at the center point of the property, but walking the long dimension should keep me no more that 2000 feet from the drone at anytime. I just worry that if I get to 25% battery and try to land at my feet, that the drone will start to head to it's original launch point.

 

[Donnie Frank]

I'm flying a very large tract of land of about 1 mile long and 1/3 mile wide. I may not get permission to center myself on the site.

Your swath of land is roughly 200 acres. To answer this question even remotely intelligently, I need more information:

* Single Grid or Double Grid?
* Overlap? I assume 75/75, yes?
* AGL and/or GSD??? Most clients are good with 1"/pixel GSD, but some want as much as .6"/Pixel.
* Connectionless flight???
* Terrain aware???

Assuming 1" GSD, single grid (based on your three battery assessment) and 75/75 overlap (industry standard), and a Phantom 4 (P4P is the best drone for mapping)...

Like you, I generally try to get as close to the center of the job as possible. But most times that is not possible. The good news is that, almost regardless of your launch point, you shouldn't be more than a mile from your drone at any given time. In the mapping game, this is child's play. My drone often flies out 2 or 3 miles, often maintaining 100% connection throughout the mission. But for corridor type missions, I have been known to fly 8 or 9 miles out, which requires a connectionless mission...but I digress...

I am unfamiliar with Pix4D, but have used other mapping programs, like GS Pro. If you're not flying Terrain Aware, GS Pro is a great program. I would consider using that one for simple grid missions. That said...

There is a highway along one side, so I thought I might start at one end and walk the long end as I fly while having a safety car following.

This is a very bad plan for many reasons.

1) This is a very small mission. No need to move your launch point or actively follow the drone.
2) While I also launch from either permitted or public land, I would never launch from a highway. Believe me when I say that the farther you get from the public eye, the better off you'll be. Wear your Dayglo green dork vest to look official.

I know I need three batteries...

Then make sure you have 4 or 5 batteries and/or a charger on hand.

...and I am concerned that if I start to land downstream of my starting point and the battery goes too low, will the drone attempt to return to it's original starting point while I'm landing it.

I don't understand the question. So instead of trying to answer this, I'll just give you a work flow.

Set up your mission so the start point is furthest from you and the end point is closest to you. You want the bird to work towards you, not away from you.

Every mapping app has the ability to "Pause" the mission. This is so you can change your battery. Most apps will ESTIMATE battery usage, but nothing is more efficient than actively monitoring your mission and managing it according to battery needs. If you're flying a single grid mission, the bird is going to fly right by you many times. When you see the battery get to 40%, wait until the bird is at its closest point to you, pause the mission, bring her back (either manually or RTH - I prefer manually), change the battery and relaunch. The bird SHOULD resume at its stopping point. That said....

The only way to predict the behavior of your software is to PRACTICE. Create a small grind mission and practice stopping the mission and changing your battery. The last thing you want is to learn how your software works and/or behaves on the job site.

I'm not sure how the algorithm work.

Practice. Create scenarios. Learn your software.

I'm using PIX4D and Phantom 4.

Does the Phantom 4 have a mechanical shutter? If not, I would consider getting a P4P. The mechanical shutter is all but necessary in the mapping game.

Any ideas? I can short cycle the flights and land at 30%, but I may not have enough total battery time if I do that.

Read above. You better have AT LEAST 50% more battery than you need. Most times everything goes as predicted, but there are times that the software bugs out and you have to relaunch, essentially wasting 10% of your battery or more. You should be prepared for that scenario.

If you're not comfortable allowing your bird to fly a mile out, you can break up the grid mission into 2 or 3 grid missions (being sure that there is 75% overlap between missions). Once you complete a mission, simply relocate and start your next mission.

Here's a screen shot of a mission I did a couple weeks ago roughly the same size as your mission. The swath of land was 1.4 miles from end to end, so we were never more than like .8 miles from the bird.


D

 

[Forby]

Your swath of land is roughly 200 acres. To answer this question even remotely intelligently, I need more information:

To keep this post simple, I'll cover things related to my question......... I'm flying single grid at 400 feet.

My drone often flies out 2 or 3 miles, often maintaining 100% connection throughout the mission. But for corridor type missions, I have been known to fly 8 or 9 miles out, which requires a connectionless mission...but I digress...

How do you stay legal at those ranges? Spotters along the way?

This is a very bad plan for many reasons.

1) This is a very small mission. No need to move your launch point or actively follow the drone.
2) While I also launch from either permitted or public land, I would never launch from a highway. Believe me when I say that the farther you get from the public eye, the better off you'll be. Wear your Dayglo green dork vest to look official.

Any mission where you cannot see your drone is a big mission. Needing to stay legal is important. We always wear vests and light our vehicles..


I don't understand the question. So instead of trying to answer this, I'll just give you a work flow.

Set up your mission so the start point is furthest from you and the end point is closest to you. You want the bird to work towards you, not away from you.
We always do this....


Every mapping app has the ability to "Pause" the mission. This is so you can change your battery. Most apps will ESTIMATE battery usage, but nothing is more efficient than actively monitoring your mission and managing it according to battery needs. If you're flying a single grid mission, the bird is going to fly right by you many times.

Not really true in all cases... To minimize flight time due to the irregular shape of the property we are flying across the shorter dimension.

If you're not comfortable allowing your bird to fly a mile out, you can break up the grid mission into 2 or 3 grid missions (being sure that there is 75% overlap between missions). Once you complete a mission, simply relocate and start your next mission.

Practice has proven that we cannot see the drone much past 2500 feet... I will re-check in software to see if I can get a better flight profile to keep the drone close.

Here's a screen shot of a mission I did a couple weeks ago roughly the same size as your mission. The swath of land was 1.4 miles from end to end, so we were never more than like .8 miles from the bird.

View attachment 27069
D

I'd still like to try to get the original question answered if anyone can?

 

[straitup]

Can you not set the RTH point to return to the controller, i think i have heard of this being done but not sure of which bird it was on, that way as you move along it would return to you.

 

[Donnie Frank]

I know I need three batteries and I am concerned that if I start to land downstream of my starting point and the battery goes too low, will the drone attempt to return to it's original starting point while I'm landing it.

It depends on a couple things.

1) Does your software have dynamic home point capabilities?
2) Does your smart device have GPS capabilities?

The software I use DOES have "Dynamic Home Point" and the iPad I use DOES have built in GPS. So I can dynamically change location while the bird is flying. My new location becomes the new home point. That said...

If I'm following the bird from a vehicle (which I sometimes do for LIDAR missions), I disable RTH anyway. If I have LOS throughout the entire length of any given flight, RTH becomes completely useless, and can even become dangerous or a hindrance in some situations. So I just disable it.

D

 

[Donnie Frank]

How do you stay legal at those ranges?

Legal? I think you mean "compliant." We're always legal. We're not always compliant. I can't map a 15 mile corridor if I have to have "eyes on" the entire time. Keep in mind we're not mapping roads. We're mapping power routes that go through hills, forest, rough terrain, etc. Setting up spotters along the way would be cost prohibitive and in some cases, impossible. These corridor missions are always devoid of traffic, buildings and/or warm bodies. So if the drone does go down, nobody gets hurt. My rule of thumb is pretty simple. Don't endanger people, animals or property. That's been my RC Helicopter mantra since the 80's.

D

 

[Forby]

Legal? I think you mean "compliant." We're always legal. We're not always compliant. I can't map a 15 mile corridor if I have to have "eyes on" the entire time. Keep in mind we're not mapping roads. We're mapping power routes that go through hills, forest, rough terrain, etc. Setting up spotters along the way would be cost prohibitive and in some cases, impossible. These corridor missions are always devoid of traffic, buildings and/or warm bodies. So if the drone does go down, nobody gets hurt. My rule of thumb is pretty simple. Don't endanger people, animals or property. That's been my RC Helicopter mantra since the 80's.

D

Huh...... I'm actually quite shocked by this.

I'm not sure the FAA would agree with your "rule of thumb". Granted, you can break the law all day long and if no one is there to see it............

God willing, your bird won't go rogue at that distance and crash into power line causing a massive wild fire that destroys thousands of acres, hundreds of homes and maybe even takes a few lives. Maybe you'll just put 50,000 people in the dark for a few days.

Honestly, the thing that surprises me most is that you have the audacity to put this in writing on a public forum. I thank you for your opinions on my topic, but I will not violate an FAA Part 107 rule.

The word "willful disregard" come to mind. Many other forums that I frequent would issue a significant time out for endorsing the breaking of laws like this.

 

[Donnie Frank]

Huh...... I'm actually quite shocked by this.

Pray tell...how would you map a 15 mile corridor through rough terrain?

I'm not sure the FAA would agree with your "rule of thumb".

You mean the guys who believe drone operators must understand METARs and cloud patterns @ 20,000 feet. You mean the guys who issue "certificates" to anyone who can pass a test, but has never touched a drone in their life???? LOL...okay...noted.

Granted, you can break the law all day long and if no one is there to see it............

I'm sure the FAA has much bigger fish to fry than worrying about a drone flying out in the middle of nowhere.

God willing, your bird won't go rogue at that distance and crash into power line causing a massive wild fire that destroys thousands of acres, hundreds of homes and maybe even takes a few lives. Maybe you'll just put 50,000 people in the dark for a few days.

I literally just spit coffee out my nose. Now THAT's some funny stuff right there. Clearly you know NOTHING about electricity, the power grid or the potential damage a NON-CONDUCTIVE 3 lb. drone can do to power lines. It's ignorance like this this drives the false sightings and sensationalized drone stories in main stream media. That said...

Read my post again. We're mapping for FUTURE power lines.

Honestly, the thing that surprises me most is that you have the audacity to put this in writing on a public forum.

I have nothing to hide. The FAA is welcome to audit any of my job sites. I never put people or property in danger. My partner and I even had a couple FSDO officers show up on one of our sites last year. We had a lovely conversation. Turns out the FAA and the FSDO officers are WAAAAAAAAAAAAAAY nicer and have MUCH more common sense than the FAA compliance trolls you see in the forums. Thank God for that, eh?

Speaking of "audacity"....

I'm shocked you publicly announce to the world that you haven't a clue how your drone, software or RTH work. But yeah...you go fly in public...and launch from the freeway, Mr. Safety.

I thank you for your opinions on my topic, but I will not violate an FAA Part 107 rule.

Dollars to doughnuts I could audit your missions and find compliance issues. The fact that you haven't a clue how your software works...now THAT is dangerous. But yeah...you be a good boy and "obey the rules." Just keep your ignorance of your drone, your firmware and your software clear of my job site...thank you very much.

The word "willful disregard" come to mind.

Actually, I was thinking the term "complete ignorance" popped into my head. But yeah...keep your nose buried in that rule book.

Many other forums that I frequent would issue a significant time out for endorsing the breaking of laws like this.

Again, I haven't broken any laws. And I defy you to cite one law I've broken.

Still wanna play????

Good day, sir.

D

 

[Forby]

Pray tell...how would you map a 15 mile corridor through rough terrain?






You mean the guys who believe drone operators must understand METARs and cloud patterns @ 20,000 feet. You mean the guys who issue "certificates" to anyone who can pass a test, but has never touched a drone in their life???? LOL...okay...noted.






I'm sure the FAA has much bigger fish to fry than worrying about a drone flying out in the middle of nowhere.





I literally just spit coffee out my nose. Now THAT's some funny stuff right there. Clearly you know NOTHING about electricity, the power grid or the potential damage a NON-CONDUCTIVE 3 lb. drone can do to power lines. It's ignorance like this this drives the false sightings and sensationalized drone stories in main stream media. That said...

Read my post again. We're mapping for FUTURE power lines.





I have nothing to hide. The FAA is welcome to audit any of my job sites. I never put people or property in danger. My partner and I even had a couple FSDO officers show up on one of our sites last year. We had a lovely conversation. Turns out the FAA and the FSDO officers are WAAAAAAAAAAAAAAY nicer and have MUCH more common sense than the FAA compliance trolls you see in the forums. Thank God for that, eh?

Speaking of "audacity"....

I'm shocked you publicly announce to the world that you haven't a clue how your drone, software or RTH work. But yeah...you go fly in public...and launch from the freeway, Mr. Safety.



Dollars to doughnuts I could audit your missions and find compliance issues. The fact that you haven't a clue how your software works...now THAT is dangerous. But yeah...you be a good boy and "obey the rules." Just keep your ignorance of your drone, your firmware and your software clear of my job site...thank you very much.






Actually, I was thinking the term "complete ignorance" popped into my head. But yeah...keep your nose buried in that rule book.








Again, I haven't broken any laws. And I defy you to cite one law I've broken.

Still wanna play????

Good day, sir.

D

How to do a 15 mile corridor? By the rules... Get a waiver

I agree about the clouds, but they do foretell the weather very well.

The FAA is in over their heads on enforcement.... I grant you this.

OK.. maybe my example of a wildfire was a long shot, but in the litigious society we live in even a negligible chance should be addressed. What about low flying helicopters, ultralights etc? You stand a chance on killing someone with that attitude.

You may not be putting people at risk, but you ARE breaking the 107 rules. I know how my drone works, I know how RTH works. I turned to this site not to be told I should just break the rules, but to get insight BEFORE I fly this mission. Clearly, my missions up till now have been small sites. I get paid handsomely for this work. I planned a a controlled trial flight to test my ideas and was merely seeking legal ideas prior to doing so. I'm normally a test and proceed guy and I don't usually look for internet guidance for this very reason.


You have broken the part 107 rules....... You can loose your privileges for that. I have flown Cessna Aircraft for years and I did not break the rules. i'm not going to start. My suggestion is to get a waiver if you can..... As they say, There are old pilots. there are bold pilots, but there are no old bold pilots...

And please.... don't advise others to break Part 107. The more pilots think of this as aviation and not a flying moneymaking toy, the better off we will all be.


Oh Yeah... I didn't say freeway, I said highway. I saw 5 cars out there today. wide shoulder. I'm doing the right thing and mapping from the road. I can see my drone at all times that way.

 

[Donnie Frank]

How to do a 15 mile corridor? By the rules... Get a waiver

Of course. Who said anything about NOT getting a waiver? We get waivers whenever they are needed. I was responding to your accusation that I was "breaking the rules" by not having spotters every 2500 feet.

I agree about the clouds, but they do foretell the weather very well.

Agreed. But anyone worth their salt doesn't use clouds to predict UAV flight conditions. I personally use Windy.com, and then I poke my head outside to see if it's cloudy. We generally don't fly if its cloudy, let alone looking like rain. We always err to the side of safety.

The FAA is in over their heads on enforcement.... I grant you this.

Glad we agree on something.

OK.. maybe my example of a wildfire was a long shot, but in the litigious society we live in even a negligible chance should be addressed.

But at what point does common sense prevail? Where do you draw the line? I'm very, very, very cognizant of the NAS and respect it completely. If 20' of that 15 mile corridor runs through controlled air space, you can bet your bottom dollar we make sure we have clear LOS during that portion. And I'm sure you're well aware that while we may not have LOS throughout the entire mission, we DO have telemetry. And we CAN spot airplanes and helicopters from many miles out. I can't go into every detail here, but rest assured, we're very safe and have our NAV/COM radios on for an added layer of safety.

What about low flying helicopters, ultralights etc? You stand a chance on killing someone with that attitude.

So sir. Read above. Those long missions fly @ 250' AGL. While I concede the possibility exists (somewhere in the 1:1B range), it's highly unlikely any helicopter will be flying that low. Even so, helicopters are easily spotted and if we suspect a collision course, we can easily pause the drone and even lower it if necessary.

You may not be putting people at risk, but you ARE breaking the 107 rules.

No, we are not.

I know how my drone works, I know how RTH works.

Apparently not. You don't even seem to know what "Dynamic Home Point" is or how it works. Half the people in this forum are unfamiliar with that term and its function. And guess what? DHP is NOT on the 107 test. So much for a f***** test, eh?

I turned to this site not to be told I should just break the rules, but to get insight BEFORE I fly this mission.

Who told you to break the rules??? Get a waiver, man. I just assumed we were all on the same page regarding waivers.

Clearly, my missions up till now have been small sites. I get paid handsomely for this work.

As do I. So I'm not willing to give up that chunk of pie because I have to fly beyond LOS.

I planned a a controlled trial flight to test my ideas and was merely seeking legal ideas prior to doing so. I'm normally a test and proceed guy and I don't usually look for internet guidance for this very reason.

Nobody told you to break the law. I merely suggested how you should manage your mission and then was nice enough to explain Dynamic Home Point to you. At least NOW you know that that option EXISTS. You're welcome.

You have broken the part 107 rules.......

AGAIN, no, I have not.

You can loose your privileges for that. I have flown Cessna Aircraft for years and I did not break the rules.

And there's the canary in the cave. Someone with a pilot's license bought a drone and now their the know-all, get-all drone authority.

Why do you pilots always feel the need to be the FAA police? I can tell you from great experience that the ACTUAL FAA are really nice, really reasonable people. It's you pilots that go WAAAAAY overboard with all the compliance crap for the sake of compliance, even when it makes zero sense. At least the FAA guys CONCEDE that the 107 is still FAR SHORT of insuring ANYTHING. You might wanna take a cue from those guys.

i'm not going to start. My suggestion is to get a waiver if you can.....

Of course.

As they say, There are old pilots. there are bold pilots, but there are no old bold pilots...

I've been flying RC since before you even had your first flight. So if it's "experience" you want to tout, I think I got ya beat. I've been following AMA rules for decades....LONG before the 107. And guess where the FAA got all it's 107 rules??? That's right...the AMA.

And please.... don't advise others to break Part 107.

Okay. And please don't assume that having a 107 means ANYTHING in regard to safety. Any HOUSEWIFE can get that certificate. I'll fill out the paperwork, but will count on my EXPERIENCE to keep the skies safe, thank you very much.

The more pilots think of this as aviation and not a flying moneymaking toy, the better off we will all be.

Touché.

Oh Yeah... I didn't say freeway, I said highway.

Touché.

I saw 5 cars out there today. wide shoulder. I'm doing the right thing and mapping from the road. I can see my drone at all times that way.

We can agree to disagree. Flying from the road causes a lot of rubber-necking. I've experienced it first hand. If YOU can see the drone from the road, so can drivers. And nothing is funner than rubber-necking a drone. What are the odds of someone crashing their car? I'd say 1,000 times MORE than a helicopter running into a drone @ 250' AGL out in the middle of nowhere. But you go ahead and roll the dice. It's your gig.

Good luck.

D

 

[licensed pilot]

 

[Donnie Frank]

View attachment 27086

I find it ironic that you ENTER a thread asking how to get OUT of a thread. It's like phoning someone to tell them you're never going to call them again...LOL....

D

 

[Forby]

It was a simple question really......

Setting RTH to follow controller was a thought, I guess I was wondering how much control the survey software takes at low battery.

With Pix4D, the DJI software is NOT running at all. I'm assuming that the pix4D software gets its low battery warning from the drone. It then displays that warning in Pix4D. If this is true, then setting the RTH to follow the controller is my best option. This way it will at least head towards me as I walk the course.

 

[Donnie Frank]

It was a simple question really......

This way it will at least head towards me as I walk the course.

Only IF:

1) Pix4D supports Dynamic Home Point (some software you must PAY EXTRA for this feature).
2) Your iPad (or RC) has GPS capability.

D