DJI P4P - High Altitude Operations

[RNCotton]

Looking for advice and tips from some of the more experienced pilots who have flown high altitude flights. Anything I should know? Any advice? Anything specific I should tell the FAA in my waiver request?

I'm a member of a local model rocket club and surprisingly enough, the FAA grants us a 6,500 foot AGL airspace waiver for a few hours the 2nd Saturday of every month, right here in the middle of Memphis. They literally divert FedEx traffic so we can fly. We do have to call the tower and give them a 10 minute heads up for any high power flights (basically, if it's going to break 3,000 feet, they give us a 20 minute window starting when we call.

We thought it would be cool to get some aerial video above some of these launches. We never like to push much more than 3,000 feet on a launch just because it makes our recovery area smaller. Even our black powder launches are in the 1,000 - 1,500 range, so obviously over the 400 foot drone restriction. So I'm wanting to basically piggyback a drone altitude waiver with our launch altitude waiver. Seems it would be a no-brainer for approval.

So, any advice for the FAA application for safety issues I should address?

Any advice for flying at 4,000 feet? Is it still considered line of sight? I mean, it's there, in my line of sight, but can you really *see* a P4P at 4K feet?


Thanks y'all ...

 

[Meta4]

Any advice for flying at 4,000 feet? Is it still considered line of sight? I mean, it's there, in my line of sight, but can you really *see* a P4P at 4K feet?

You are confusing Line-of-Sight with Visual Line-of-Sight VLOS.
They aren't the same thing.

 

[RNCotton]

You are confusing Line-of-Sight with Visual Line-of-Sight VLOS.
They aren't the same thing.

So the FAA says I have to be able to keep eyes on the aircraft, and at 4,000 feet horizontal I can't see it, so that's a violation. But at 4,000 feet vertical, I still can't see it, but that's OK?

 

[Meta4]

So the FAA says I have to be able to keep eyes on the aircraft, and at 4,000 feet horizontal I can't see it, so that's a violation. But at 4,000 feet vertical, I still can't see it, but that's OK?

Where do you get the idea it's OK?
If you have to keep it in visual range, you have to keep it in visual range regardless of direction.

 

[RNCotton]

Where do you get the idea it's OK?
If you have to keep it in visual range, you have to keep it in visual range regardless of direction.

That's exactly what I was saying.

Thus my questions on what I need to put in place to accomplish the goal of shooting video of some of our launches.

 

[BigAl07]

In essence you'll be asking for a VLOS waiver and a Max Altitude waiver in the same breath. While it "should" be an easy thing to get since you are already in "Cleared" airspace during the rocket launch nothing is ever as it should be when working with a Govt agency. Our logic and theirs aren't exactly the same.

This should be interesting. . . .

 

[R.Perry]

So what altitude are you going to be asking for, the 4000 ft max? By the way, don't shoot your drone down.

 

[LUIS MARTINEZ]

So what altitude are you going to be asking for, the 4000 ft max? By the way, don't shoot your drone down.

" By the way, don't shoot your drone down..." But it'll make for a cool video!!!

 

[The Editor]

The permission may not be as straightforward as some may think.
The reason being a rocket goes up.....then goes "Phut, phut, wheeeze" when it runs out of fuel and then starts it crash course to Terra Firma (usually slowed by an arresting device such as a parachute).
Other than winds aloft, not much else exciting happens.
A UAV at 4,000 ft agl on the other hand could develop a fault which sees it fly horizontally at full speed at that altitude which means it could easily stray outside of its waiver airspace.

There are other factors to consider such as relative humidity at altitude with the differing air pressure above and below the prop surface which can cause iceing to occur. It does not have to be below freezing for ice to form on props.

 

[RNCotton]

In essence you'll be asking for a VLOS waiver and a Max Altitude waiver in the same breath. While it "should" be an easy thing to get since you are already in "Cleared" airspace during the rocket launch nothing is ever as it should be when working with a Govt agency. Our logic and theirs aren't exactly the same.

This should be interesting. . . .

I've got a phone call scheduled with local FSDO this morning to discuss what I need to address for safety concerns. I'm hoping it will be a simple matter of just adding it as a rider to the launch waiver. But, they'll probably make me do the whole portal thing.

 

[BigAl07]

I do have one question for @RNCotton : How are you going to get your AC over the 1620' hard altitude limit? I fully realize there are "hackish" ways etc or you could use a non-DJI product but the title of the thread is DJI-P4P.... so I'm curious to know how you'll bypass the DJI Firmware limit.

 

[RNCotton]

I do have one question for @RNCotton : How are you going to get your AC over the 1620' hard altitude limit? I fully realize there are "hackish" ways etc or you could use a non-DJI product but the title of the thread is DJI-P4P.... so I'm curious to know how you'll bypass the DJI Firmware limit.

According to the specs, ceiling is 6,000 meters, that's 19,600 feet and some change. Did they change that?


Talked to FSDO, altitude isn't the issue and since we already have 6,500' it wouldn't be a problem to request a 3,000 foot altitude for the video flights. The problem is beyond visual line of sight. Realistically, the max altitude you can see one of these is what ... 1,000 feet? So that's the problem. And it's a catch-22. I could add some lighting and go fly to see how high I can reasonably keep eyes on the aircraft, but I can't exceed 400' without a waiver, and I can't get a waiver if I can't tell them how high I can see the aircraft. And if I do it anyway, then tell the FAA "Yeah, I tested it to 2,500 feet in daylight" ... I'm sure they would say, "Oh you did, eh?"

Maybe we can get some leeway to test lighting and visual observation at altitudes over 400' as part of our PILOT program.

 

[Moosewax]

According to the specs, ceiling is 6,000 meters, that's 19,600 feet and some change. Did they change that?


Talked to FSDO, altitude isn't the issue and since we already have 6,500' it wouldn't be a problem to request a 3,000 foot altitude for the video flights. The problem is beyond visual line of sight. Realistically, the max altitude you can see one of these is what ... 1,000 feet? So that's the problem. And it's a catch-22. I could add some lighting and go fly to see how high I can reasonably keep eyes on the aircraft, but I can't exceed 400' without a waiver, and I can't get a waiver if I can't tell them how high I can see the aircraft. And if I do it anyway, then tell the FAA "Yeah, I tested it to 2,500 feet in daylight" ... I'm sure they would say, "Oh you did, eh?"

Maybe we can get some leeway to test lighting and visual observation at altitudes over 400' as part of our PILOT program.

What BigAl means unless you are hacking your DJI you are limited to 500 meters (1600ft or so) above your takeoff/home point (AGL). That's the DJI software limiting you.

You can launch at 5000ft AMSL no problem and then only go up to 1600ish ft AGL relative to your takeoff/home point.

 

[BigAl07]

According to the specs, ceiling is 6,000 meters, that's 19,600 feet and some change. Did they change that?


Talked to FSDO, altitude isn't the issue and since we already have 6,500' it wouldn't be a problem to request a 3,000 foot altitude for the video flights. The problem is beyond visual line of sight. Realistically, the max altitude you can see one of these is what ... 1,000 feet? So that's the problem. And it's a catch-22. I could add some lighting and go fly to see how high I can reasonably keep eyes on the aircraft, but I can't exceed 400' without a waiver, and I can't get a waiver if I can't tell them how high I can see the aircraft. And if I do it anyway, then tell the FAA "Yeah, I tested it to 2,500 feet in daylight" ... I'm sure they would say, "Oh you did, eh?"

Maybe we can get some leeway to test lighting and visual observation at altitudes over 400' as part of our PILOT program.

@Moosewax nailed it.

The "Service Ceiling" of the aircraft is 19,600 which only means if you take off from the top of a 19,000 foot mountain top the aircraft will hit a hard ceiling of 19,600 well before you hit the software limit of 1,620+/-' from take off point.

The DJI Software limit is at 1,620' if you change the setting in the app to 500 meters ( I think default is 120m or 400'). I believe the only way around this limit is hacking the firmware and I'm not sure how that would fair long-term with regards to warranty, SOP with dept etc.

 

[BigAl07]

According to the specs, ceiling is 6,000 meters, that's 19,600 feet and some change. Did they change that?


Talked to FSDO, altitude isn't the issue and since we already have 6,500' it wouldn't be a problem to request a 3,000 foot altitude for the video flights. The problem is beyond visual line of sight. Realistically, the max altitude you can see one of these is what ... 1,000 feet? So that's the problem. And it's a catch-22. I could add some lighting and go fly to see how high I can reasonably keep eyes on the aircraft, but I can't exceed 400' without a waiver, and I can't get a waiver if I can't tell them how high I can see the aircraft. And if I do it anyway, then tell the FAA "Yeah, I tested it to 2,500 feet in daylight" ... I'm sure they would say, "Oh you did, eh?"

Maybe we can get some leeway to test lighting and visual observation at altitudes over 400' as part of our PILOT program.

You can "Estimate" (add some fudge factor) your VLOS distance horizontally and just use that as your vertical distance. Of course as you climb higher in the atmosphere you'll most likely get diminshed visibility so keep that in mind.

 

[R.Perry]

I have another question. First of all this sounds like a really cool idea. Lets say big brother give you an ok for 4000 ft, and DJI knowing you have the clearance removes their limits.
How long is it going to take your P4 to climb to 4000 feet, then shoot the launch, and return and land? You don't have a real atmospheric issue until you get over 5000 feet but you will lose a little lift especially if it is a warm or hot day. So your drone is going to be using a little more power to maintain the altitude than it normally would.

I flew my P4P at 9000 feet and it really struggled in that thin air, now I realize you aren't coming anywhere near that but density altitude may play a small factor.

 

[BigAl07]

I flew my P4P at 9000 feet and it really struggled in that thin air, now I realize you aren't coming anywhere near that but density altitude may play a small factor.

Ah the ole infamous Density Altitude . . . Live by it or die by it LOL.

I made the mistake of "Assuming" it was ok and took off "heavy & slow" on a hot smoldering day. I honestly thought the plane was dragging an anchor or something. I got lucky and didn't push it to the breaking point but after that day I always... ALWAYS confirmed the DA.

 

[RNCotton]

@Moosewax nailed it. The DJI Software limit is at 1,620' .

Ahh, gotcha. I wasn't aware of that "feature." It's kind of like, what's the top speed of my car? I dunno. I've never had a reason to go that fast. Same thing with the aircraft, I've never had a reason to go above 400'. Thanks for that info.

 

[The Editor]

Any professional operator should know the working limits and ceiling of operation for their aircraft. In fact, it forms part of a commercial UAV ops manual!
I guess there is 'professional' and Professional.

 

[RNCotton]

How long is it going to take your P4 to climb to 4000 feet, then shoot the launch, and return and land?

I've never measured it, but according to DJI specs, climb rate is 1,000 feet in a little under a minute. Powered decent rate is about 800 feet in a little under a minute. So when I was putting all this together to see if it was even feasible to do it, I was allowing 4 minutes to climb, and allowing 5 for decent. For our high-power flights, we give a 10 minute heads-up call to ATC and they give us a 20 minute launch window starting at that point. So 5 minutes before launch, put the P4P in the air and get positioned. I figure that gives me 10 solid minutes to hang out, then another 5 to return. 20 minutes total flight time, which is the same as our launch window. I think it's doable, especially if they are able to launch on the first hit without me having to loiter around for 10 minutes.