When the tower says "contact when 2 miles out", does that mean nautical miles? In other words, when talking aviation, are the units always nautical miles?
When the tower says "contact when 2 miles out", does that mean nautical miles? In other words, when talking aviation, are the units always nautical miles?
Some planes have air speed indicators in statute MPH. That scale makes it seem like they go faster.
It makes no difference to the controller when you make a call like that. They're just looking for you in the approximate area.
Not much bugs a controller more than using a precise number off your GPS, such as saying you're 2.43 miles out, or 153.4 miles from some VOR.
Well, if you are on the ground weather is expressed in farenhite and statue miles. once airborne its Celsius and nautical miles. Air space is measured off in NM, but cloud clearance is statute miles. They do this just to mess you up.
NM's have a relationship to latitude. Those black lines on a chart that run north and south have "tic" marks spaced in nautical miles and are a handy scale. Don't try it with the lines running E & W. They are distorted by the way they converge near the poles. They also do this to mess you up.
Bob
I have always thought this to be useless info. Being how many miles out one is. One day I announced so many miles out. By the time I reached the airfield someone had taken it. When I spoke with this someone they said they waited and waited and could not see me. I announced around 4-5 miles out. I now state how many miles out and how many mins I believe to be away. I am speaking of course at non-towered fields. Now I say 5 miles out and over 5 mins away. It sure looks closer when in the air then it does when on the ground.
My point if you are flying a bird that flies 100, a few miles out and you are on top of the airport. But if you fly something with a ground speed of 30-50 mph, and you are 5 mins out at 5 miles. Five mins seems like forever when sitting and waiting on the ground.
Now if you announce 2 mins out at these slow speeds you can be seen from the ground at the airport you intend to land. Kinda defeats the purpose of announcing when in the pattern already. So to say 5 miles out, those on the ground they believe you to be a min or two out, not 5 mins out.
IMHO miles out is useless info unless already in the air in the pattern. Then it is now useful info. But not to those on the ground looking up and waiting.
On the occasion when I find myself sharing the skies around our airfield I usually amend my location call with an estimated time as well, as I'm in the putt-putt crowd.
"Ten miles and ten minutes out from the south" may not be technically correct, but it lets the other guy know to look for something going slow.
The opinions and statements of this poster are largely based on facts and portray a possible version of the actual events.
Thanks everyone - just trying to learn the distances from the local airport appropriately.