Flying On the Line

dilpickle · Apr 4, 2017

I have a job that requires me to fly in an area that falls beneath the class C airspace "line". The property is literally right beneath the solid magenta line (SFC/40). I made sure to check the 'width' of the line with Google Earth using coordiantes I pulled from skyvector.com.

Its not inside the circle, its right beneath the line. Does the controlled airspace start at the outside of the circle, beneath the line, or within the circle?

Thanks

Richard R · Apr 4, 2017

If you are that close, I wouldn't depend on using the width of a line to determine if I was inside the airspace. Class C is normally 5 nm from the airport. That should be your metric.

dilpickle · Apr 4, 2017

Yes and I have used google earth to draw various 5nm circles that all fall right on top of/right next to the property I wish to fly. If I draw the circle from what I perceive to be the center of the airport, I'm outside the circle. When I draw the circle from a different spot at the airport, then I'm just inside.

If I go off of aeronautical charts and the solid magenta line, I'm right under the line.

I am a part 107 certified pilot and this will be a flight for commercial purposes.

If I drift even an inch into the Class C airspace, I'm in violation right?

Richard R · Apr 4, 2017

Technically, yes. Wouldn't think it likely that the FAA will notice. One thought. Depending on which firmware/software you have loaded, you might get grounded by the DJI NFZ barriers!

Melt in the Sun · Apr 5, 2017

Controlled airspace is inside the line. Shaded areas are not part of the Class C, in this case.

daveisim · Apr 5, 2017

dilpickle said:
If I draw the circle from what I perceive to be the center of the airport, I'm outside the circle. When I draw the circle from a different spot at the airport, then I'm just inside.

Use the official FAA co-ordinates of the airport. You can find then in the download at Digital - Chart Supplement (d-CS) Note: The former A/FD is replaced with this publication.

Using B4UFLY and/or ArcGIS Explorer (with UAV_107_Airspace) will give you an airspace boundary outline just couple pixels wide no matter how much you zoom in.

Even better, go to the place, note the exact GPS co-ordinates , look up the actual FAA official airport co-ordinates and do a great circle distance between the two.

Richard R · Apr 5, 2017

daveisim said:
Use the official FAA co-ordinates of the airport. You can find then in the download at Digital - Chart Supplement (d-CS) Note: The former A/FD is replaced with this publication.

Using B4UFLY and/or ArcGIS Explorer (with UAV_107_Airspace) will give you an airspace boundary outline just couple pixels wide no matter how much you zoom in.

Even better, go to the place, note the exact GPS co-ordinates , look up the actual FAA official airport co-ordinates and do a great circle distance between the two.

Once yo have the coordinates. you can go to this site to calculate the distance between them Calculate distance and bearing between two Latitude/Longitude points using haversine formula in JavaScript.

BigAl07 · Apr 5, 2017

If it's that close I'd error on the side of caution and cover your assets. Better SAFE than sorry.

daveisim · Apr 6, 2017

Of course if you do a distance calculation, be sure it's in NM (Nautical Miles), not SM (Statute Miles).

BellevueV · Apr 13, 2017

...sounds like it would be easier to contact the airport. - have you done the job yet?

Richard R · Apr 13, 2017

No one in the tower has time to do your navigation for you. If you can't figure it out, back up and give your self what ever your margin of error is.

BellevueV · Apr 13, 2017

well, FWIW - it sounds like he is right on the line - and will mostly likely fly into the airspace - and as a part 107 pilot - which he says he is - he shouldn't have an issue (edited/corrected - following 107.41)
- it's a class C - so not a big airport.

...I don't use B4Ufly - I use AIRMAP