Do you ever fly over 400 ft in US?

[old man mavic]

Thanks for that quick reply....
(i'm new to this, but loving it)
the Mavic 2 smart controller seems to maintain height data relative to the launch point.
is there a feature that gives elevation with respect to the drone as it travels?

not once out of bottom sensor range

 

[gnirtS]

So what about the Barometric sensor on board? It measures altitude based on air pressure similar to commercial aircraft. It’s not 100% accurate and in the commercial world the pressure at the runway altitude is taken as a reference. Not used for landing though - there are cases where aircraft have crashed when the altitude of the runway has not been correctly set.

Then there is the altitude calculated by the GPS.

Barometer just measures pressure. Crudely this is just altitude. When calibrated height above sea level (QNH) or far less commonly, aerodrome level (QFE). Or standard pressure settings in higher class controlled airspace.

Altitudes ATC and flight planning wise are always given above calibrated mean sea level unless states (and its very rare to do anything else in normal operations).

It tells you nothing about the immediate height under the aircraft at all - it cant. But it doesn't have to. Its not important.

In pretty much all manned aviation QNH/Barometric is used on the approach, calibrated to mean sea level. Including for pretty much every standard and instrument approach procedure. Its also used in the flight levels and everything else. Baro altitude IS the gold standard. So yes it is used for landing, almost all the time.

Circuit heights, glideslope checks,decision heights and everything else are generally ALL given as barometric above sea level so it is "used for landing". GPS is pretty much never used (and GPS isnt a mandatory requirement even for aircraft, a barometric altimeter is).

Because actual height over the ground directly beneath you is something you very very rarely need to know.

You don't land a plane based solely on the altitude readout. You land it by looking out of the window and/or following instruments and charts. You also have a declared minimum altitude where if you cant see the runway visually you go around.
Yes mis-calibrations are possible but that-s why every part of a flight has checklists and crosschecks to significantly reduce the error.

The Mavic calibrates its barometer at the takeoff spot. So it basically sets QFE. So it tells you the barometric height above takeoff point which is not the same as ground. The VPS alone can tell you height above ground and they only work at 20-30ft or so.

As for GPS altitude, forget it. Its inaccurate and thats before you dial in the various datum, geoid corrections and so on. Simple arent going to get a GPS anywhere near accurate in altitude in a cheap consumer drone to make it worth switching from the barometer....and obviously it needs a good GPS signal to even work at all.

 

[gnirtS]

Biggest problem is knowing the altitude at the launch point. GPS should be able to give you this combined with the barometric sensor. Are we saying sea level is not taken into account?

GPS altitude is in the image EXIF data. But like most GPS altitude, its inaccurate. Also which sea level? You have altitude above geoid, height above mean sea level, different datums WGS84 straight vs EGM96 or other gravity models.
All of those will produce different results.
The Earth is not a perfect sphere. Its got bumpy and lumpy bits and so on. There are various models for converting those, all are going to be a bit different.

Example where i am here, Bog standard non converted WGS84 style GPS altitude here, at the mid tide line sea level gives me an altitude of -88ft. Converted to EGM86 i get my locally corrected altitude which is accurate to maybe 5m or so. But because the other isnt round that correction changes everywhere.

This is BEFORE you add the GPS error on which at *best* is 1.5x horizontal, sometimes far worse, especially without differential corrections.

So basically theres no easy way of doing it and its not that useful.

Far more useful is barometric height above takeoff point which is a calibrated reference at the time of taking off, does not rely on satellites, different co-ordinate systems and so on.

The mavic does record absolute and relative altitudes via GPS in the metadata. But in a flight i dont need GPS data, it doesnt tell me exact height above anything useful and is often less accurate than the barometer for take-off height readings.

 

[SkyeHigh]

Thanks gnirtS. So just out of curiosity if you were to land in Death Valley for example, would the charts show -282ft barometric pressure equivalent for the runway?

 

[sar104]

Thanks gnirtS. So just out of curiosity if you were to land in Death Valley for example, would the charts show -282ft barometric pressure equivalent for the runway?

 

[SkyeHigh]

View attachment 102572

Thank you kind Sir!

 

[jnnyr]

Not to be the drone Police but if I see a video that looks to be over 400 feet I am going to start reporting them. It is because of these people, there are so many rules and regulations that are hurting our hobby and because of the time and effort I put in to be legal I just don’t feel like my fun should be ruined by them.

Oh, and who exactly are you going to report them to? The altitude police?

 

[sar104]

Oh, and who exactly are you going to report them to? The altitude police?

Presumably the local FSDO - they would be the appropriate authority.

 

[Florida Drone Supply]

While you could get some great shots going over 400ft. I would not risk it. For the same reasons as mentioned above, FAA regulations, low flying helicopters, and depending on high you go losing sight of your aircraft.

 

[jnnyr]

Presumably the local FSDO - they would be the appropriate authority.

Don't bother. I got a first hand lesson there is absolutely nothing they can do. I contacted the FAA regional office responsible for NYC air traffic violations and they said unless they literally caught someone in the act there's nothing they can do. This [Language removed by ADMIN] had video's of himself flying over the hudson river. Maybe the most restricted and congested airspace in the country outside of Washington DC.

 

[sar104]

Don't bother. I got a first hand lesson there is absolutely nothing they can do. I contacted the FAA regional office responsible for NYC air traffic violations and they said unless they literally caught someone in the act there's nothing they can do. This [Language removed by ADMIN] had video's of himself flying over the hudson river. Maybe the most restricted and congested airspace in the country outside of Washington DC.

Another example of random FAA responses unfortunately. The FAA has demonstrably taken action over sUAS violations that were either self-reported by posting videos etc., or reported by third parties.

 

[Motorcycle Rider]

Remember that you are only seeing the drones height above your initial take off point. Living in a hilly area, if i took off from my yard, climbed straight up to 200' indicated, and flew around, I would run into things such as trees before long, and at other times be at 600' agl. So it would be very easy to be over 400' agl, despite the altitude readout on my controller only saying 200'. Have I broken the 400' agl rule, almost guaranteed that I have, but the display in my hands has not ever read over 400. It has also been telling me 350' as the drone barely missed tree tops. So for some of us, the displayed altitude means nothing.

 

[Brockrock]

FAA Part 107 here, and I rarely go to 400’ and never over. I am also a commercial fixed wing pilot, and during my early days of building flight time, one of the many things I did was take photographers and tourists on scenic flights around the coastal areas of New England. Generally, the minimum safe / legal altitude for such flights was 500’, but in almost all cases, especially with news and other commercial photographers, they always requested that I get lower, and their ideal would have been +/- 200’. There were cases, such as flying along the storm battered bluffs on the southern coast of Block Island, RI where I could safely and legally fly at these lower altitudes, but this was vary rare.

As such, I do find it curious that so many folks insist on ascending to these higher altitudes, regardless of the legalities associated with where they are..

 

[SkyeHigh]

FAA Part 107 here, and I rarely go to 400’ and never over. I am also a commercial fixed wing pilot, and during my early days of building flight time, one of the many things I did was take photographers and tourists on scenic flights around the coastal areas of New England. Generally, the minimum safe / legal altitude for such flights was 500’, but in almost all cases, especially with news and other commercial photographers, they always requested that I get lower, and their ideal would have been +/- 200’. There were cases, such as flying along the storm battered bluffs on the southern coast of Block Island, RI where I could safely and legally fly at these lower altitudes, but this was vary rare.

As such, I do find it curious that so many folks insist on ascending to these higher altitudes, regardless of the legalities associated with where they are..

They simply don’t care about anyone else. They’re arrogant and believe rules don’t apply to them. We have institutions for people like that.

 

[1bad]

Not to be the drone Police but if I see a video that looks to be over 400 feet I am going to start reporting them. It is because of these people, there are so many rules and regulations that are hurting our hobby and because of the time and effort I put in to be legal I just don’t feel like my fun should be ruined by them.

This makes you a tool as you are not seeking to understand if they are legally flying or not. Your just making statements full of assumptions and to think that you could cause someone grief in life because of a situation you have made assumptions on and that you know nothing about. That is border line crazy, and I would also be willing to bet you would not make that person aware of the report, or tell them in person that you are doing so.

You talk about YOUR fun, yet you would blindly impact others fun or business based in unproven truths......hmmmmmmm.

 

[cav01c14]

1642 ft is the highest it will physically let you go.

 

[Motorcycle Rider]

This thread is interesting, we have some guy on a power trip, and thinking that he can tell by a video how high agl a drone is. Then wants to report people, based on his obviously poor judgment skills.

Some who say they have never flown over 400' agl, maybe did, but refuse to acknowledge it. Those low areas people fly over, greatly increase their agl altitude, who gives a crap what they see on their remote screen. And some who are honest, and say yes they have. I know that I have, yet my remote said that I was only at 6' as I flew over the edge of a hill.

 

[Motorcycle Rider]

1642 ft is the highest it will physically let you go.

All models, or just some?

 

[ChipDjipro]

My buddy just told me his mavic 1 does not let him go over 400 feet now. He had no problem in the past.

 

[Motorcycle Rider]

I was hoping in the future to fly mine up into the mountains and over glaciers etc. So if they only go 1600 feet above their take off spot, that will be disappointing. I was just about to order a Zoom 2 and smart controller, but might have to try a different brand, if all dji products have this restriction.