moca & rth settings

pepper

Well-Known Member
one of the drone policies where i work is that we establish the moca (minimum obstacle clearance altitude) on every scene and set the rth (return to home) altitude accordingly. to do this you level out your camera until it's set to 0 degrees. identify the tallest obstacle and fly the drone upwards until the top of the tallest obstacle is midway up the screen (or on the center of the big X across the screen). check the drone's altitude and that's how high the tallest obstacle is. set your rth altitude higher than that obstacle. we tend to go 30' higher, as long as we're still within 400' agl. if we are flying multiple drones we'll set each additional drone(s) higher by 20' increments, even if we don't plan on flying them simultaneously. this way if there is a problem and all of the drones come back at once, they don't crash into each other.
 

AlanLichty

Moderator
Good plan. I fly straight up to what I think should be my clear space and do a 360º scan to make sure I have a clear path and then make sure my RTH is set for that. I rarely ever use RTH to bring my drone back but like to make sure that the RTH settings are correct in case of a controller failure. I do have RTH set for the action to take in case of signal loss.

Can't say that I have ever been flying with others using the same launch area before.
 

pepper

Well-Known Member
Good plan. I fly straight up to what I think should be my clear space and do a 360º scan to make sure I have a clear path and then make sure my RTH is set for that. I rarely ever use RTH to bring my drone back but like to make sure that the RTH settings are correct in case of a controller failure. I do have RTH set for the action to take in case of signal loss.

Can't say that I have ever been flying with others using the same launch area before.
we don't use rth either. our sop states that if we have control of the craft, we do everything manually. but it's good practice to set up the failsafe in case things go catastrophically wrong. this is the one policy i've worked into flying with my personal drone. i don't fly up and do the full moca stuff, but i'll take a look around and guesstimate the height and set the rth accordingly if it's lower than my guess.
 

JimFox

Moderator
Staff member
How interesting! Thanks for letting us into your world with how you operate your drone. I hadn't heard of Moca before and thought you were referring to a type of coffee.... ;)
 

AlanLichty

Moderator
we don't use rth either. our sop states that if we have control of the craft, we do everything manually. but it's good practice to set up the failsafe in case things go catastrophically wrong. this is the one policy i've worked into flying with my personal drone. i don't fly up and do the full moca stuff, but i'll take a look around and guesstimate the height and set the rth accordingly if it's lower than my guess.
I fly around tall trees a lot so I don't take my chances. I actually did the moca bit the first time I flew up from my driveway since I had no idea how tall our neighborhood trees were (125') and just got in the habit of scanning my intended flight area ever since.
 

AlanLichty

Moderator
Beth - out of curiosity do all of your pilots have pt. 107 certification or do you have teams for your operations with a pt. 107 Pilot in Charge that supervises someone else working the controller?
 

pepper

Well-Known Member
Beth - out of curiosity do all of your pilots have pt. 107 certification or do you have teams for your operations with a pt. 107 Pilot in Charge that supervises someone else working the controller?
everyone on a drone team must have a part 107 prior to joining. we designate an rpic who is ultimately responsible for each mission, however anyone from the drone team can fly. we require at a minimum an rpic and a vo for each drone flight. the vo doesn't necessarily have to have their part 107 or be part of a drone team, we've used firemen in a pinch, but they won't be allowed to fly. most of our missions are 1 drone and multiple flights in a limited area. for special events we'll have multiple drone teams from one or more agencies flying at the same time. apart from an rpic, pilots and vo's, we might have a one or two people running tech for larger events. the tech people charge batteries, make sure that the air data video stream is stable, keep an eye on the weather and communicate with other agencies on the radio. sometimes we'll have a cop on the drone team who will be in charge of taking notes in case the footage/pics are used for evidence. for those, we usually just trade cards with the cop so the chain of evidence isn't broken.

to give you an idea of how this all comes together, polar bear plunge is coming up. it's an event where a few hundred people raise money by jumping in the freezing ocean in january. everyone lines up along the beach in a zone that's about 3/4 mi long and goes in to the water at the same time. some get out right away, some stay in until they're forced out. last year my agency ran 3 drone teams of 2-3 men along the beach, 1 drone team on the north and south ends over the water looking towards the people and one drone center over a building looking into the ocean. we used flir cameras on the drones and if anyone was in distress, we'd radio their position out and life guards and the coast guard would respond. the various police agencies had drone teams that flew the side streets in town and made sure nothing shady was going on, and do searches when a missing child was reported. the dept. of natural resources flew the beach north and south of the event zone to make sure nobody was trying to get in the ocean, or causing other problems.
 

AlanLichty

Moderator
Interesting to hear how an event like this plays out - that's a lot of drones in the air at once for event like the polar bear plunge. Is an event like that declared a TFR to keep unauthorized pilots out of the immediate area? Seems like it would be necessary for participant safety and to prevent any interruptions to the efforts of the teams. Are the drones used in such an event equipped with prop guards for OOP or do you just make sure the drones are never directly over people?

You can get away with just the rpic being 107 under FAA rules but your approach would give you a more knowledgable team. Nice place for overkill with the knowledge base.
 

pepper

Well-Known Member
Interesting to hear how an event like this plays out - that's a lot of drones in the air at once for event like the polar bear plunge. Is an event like that declared a TFR to keep unauthorized pilots out of the immediate area? Seems like it would be necessary for participant safety and to prevent any interruptions to the efforts of the teams. Are the drones used in such an event equipped with prop guards for OOP or do you just make sure the drones are never directly over people?

You can get away with just the rpic being 107 under FAA rules but your approach would give you a more knowledgable team. Nice place for overkill with the knowledge base.
when my state first started investigating drone use for public safety we had a board of people from every interested agency (state and town levels) to investigate the possibilities. they're the ones who talked to the state insurance section, as well as faa input and some other things and decided everyone needed to be part 107 certified. they do teach that only the rpic needs to be certified in the fire school part 107 classes, but also make it clear that we will not be on any drone team without certification.

some events, like large music festivals, have tfrs in place with a standing waiver for event support. we try not to fly over people, if we have to then we go over them as quick as possible. we have waivers to do that without the standard safety precautions in emergency situations. if all else fails, just submit your screw up to nasa and you're in the clear. we always intend to work within the faa's rules, but we get a little more leniency since we're dealing with public safety. not all of our missions are planned special events, some are incidents that we can't do any preplanning or get waivers for.
 

pepper

Well-Known Member
Very cool - sounds like an interesting place to work :)
we don't have a full time drone section setup in the state yet, each agency has full time employees who flying drones outside of working hours or assigned to drones for a specific event. i'd jump on a full time drone team if we did have one. i work in the 24/7 ops center, we usually get first dibs to fly big incidents since the first responder pilots are being used as first responders. we'd normally setup shop in a command post anyway.
 

AlanLichty

Moderator
Still sounds like your state has gone a long ways down the road towards setting up a full time unit. I retired from working IT for Clark County Washington in 2015 and there wasn't any sort of framework in place that something like this would have fit under. At the time the City of Vancouver and Clark County had a shared network infrastructure that included the City PD, Vancouver Fire, County Sheriff Dept. and the 911 call center along with the rest of City/County government offices so the potential was there although I understand they broke a lot of the shared infrastructure up after I left. Playing with drones under that umbrella would have been fun but there's no way they would have unchained me from network and systems administration duties anyway 🤣 I did find the 24/7 on-call lifestyle of the first responders a bit constraining in the long run.
 

pepper

Well-Known Member
we don't have any IT agency personnel involved in drones. we should though, we've done cell tower & cell tower equipment inspections for them before. no 911 operators either, but plenty of cops. yes, the 24/7 job life is draining at times.

we have a lot of problems with our IT section. they treat us like the rest of the state. 911, operations centers, emergency management and police should be on a separate network with separate servers with different update and redundancy rules. not to mention different firewall rules and blocked site filters. i have to get an ipad from outside the state network because the state's bloatware...err..much needed security software blocks airdata and keeps me from sending live video back to cp or the ops room.
 

AlanLichty

Moderator
You are reminding me of why I am glad I am retired - I hated doing network security stuff. Your IT folks could set up a portal to allow you to dump files in but I can see where they might hesitate on the live feeds. We were using Verizon for most of the remote first responder communications to the 911 center but no one was trying to do live video feeds.

My home network and computing systems are the only ones I have to care about now :)

Flying my drone as a camera is strictly for fun although I do fly as pt. 107.
 

pepper

Well-Known Member
now you have to take it one step further. we use portable cameras hooked up to cdmas to send live feeds at a special event back to a command center, or even to multiple command centers (the on scene joint ops center and the actual ops/command centers for each agency). problem is, once that special event fills up with people, your chances of getting a signal through is nil. so now there's a special first responders mobile network that we use instead of verizon, which is supposed to guarantee first dibs on the cell network. doesn't always happen, but it's a better bet than verizon. but even that gets killed if one of the federal alphabet agencies comes in and blocks cell traffic in the area. i'm glad i don't work in IT. it's just a major headache now.
 

AlanLichty

Moderator
The need for ever more bandwidth isn't going to level off soon. IT departments got clobbered when the police started using body cameras all day and all came back with terabytes of video to dump into the network at the end of their shift. Lather rinse and repeat for the next shift.

It was bad enough keeping up with everything back when I left. After 37 years I decided I had done enough and it was my turn to actually use my computers for something besides work :)
 

pepper

Well-Known Member
i hear that. there's too much tech out there now and most of it is discarded the minute something newer and shinier comes available. and every bit of it needs bandwidth, fiber installation and maintenance. and that's if you can get the parts for it after the first few years.
 

AlanLichty

Moderator
The one given is that for every New Shiny Thing (NST) that comes along and catches management attention some poor schmuck (like I was) has to learn everything about the NST and make it work just in time for it to be replaced by a newer NST. Retirement was an incredible relief from that lifestyle.
 

pepper

Well-Known Member
unfortunately, our new shiny things don't stay new and shiny very long. they're quickly replaced by the newer and shinier.

on an unrelated note, one of our mavic 3s fell out of the sky two days ago. the pilot said it started drifting uncontrollably before dropping out of the sky. they sent some poor red shirt with waders on into the swamp up to his chest to retrieve it. despite being mostly submerged it still seems to work, except for the camera. we'll see what dji says. i don't know if he had installed the latest firmware update or not.
 

AlanLichty

Moderator
There has been a flurry of updates for both the M3 as well as the controllers and app software. They all need to be in sync as far as versions go. Out of curiosity do you have an upgrade policy in place for keeping all of your drones/controllers in sync for firmware and app versions?

The newest feature is waypoints for the M3 and you might be able to take advantage of that with your operations. I haven't decided what I will do with that quite yet. I did fly a bit today with the new versions and everything seemed stable but I didn't try out using waypoints yet.
 
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