Distance Measurement and Reference point

What point is being used to determine distance from the dropzone? Is it the landing spot set for the dropzone, or something else? If it’s not the landing spot, how can I tell what it is using? I assume that distance is statute miles, not nautical miles? The reason I ask is that I’m trying to compare what the One is saying to what the pilot is using for the spot. They never seem to agree.

I’ve always used the distance as a guide and more of an estimate. I like to look more at the landmarks to truly know where I am. If jump run is going north but the offset east changes a bit from jump to jump then the dekunu will have different readings. The landmark never moves though.

Pilots are kinda the same. If I tell them 2 miles to the north. I can expect it to be anywhere from 1 to 3 miles depending on the pilot. So again I tend to use landmarks to see if I am in the right vicinity. I never go in expecting the dekunu and the pilot to be in 100% agreement. I like to think of it as a triangle. The pilot will do a straightish line where they give you your requested distance. There is also an offset from the dz and thus landing area. The dekunu distance is then the hypotenuse of that triangle.

To answer your question, I’m pretty sure its statute miles everywhere. Internally, it’s all metric and then gets converted over to imperial for us americans and most american’s don’t know that a mile and nautical mile are slightly different.


@kat00 As far as i’m aware, nautical miles should be in use for aviation in most places as the ICAO designates it (edit - sorry, I just realised what your point actually was :expressionless: my bad)

@robs007 distance on the Dekunu is from whichever landing point you have selected at the dropzone. It is displayed in statute miles (why oh why :expressionless:…but hopefully as more people request it the additional format nautical miles will move up the priority list) I found that the plane gps vs. my dekunu (we used the exact same measuring point) were similar up until 0.6mi/nm away, then they began to separate (in the case of a straight jump run over the top of the landing area, as @kat00 said if there’s horizontal offsets applied then distance will be different)

1 Like