Miles - always nautical?

[kdahlhaus]

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?

[martymayes]

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?

No, not all aviation miles are nautical

[PaulDow]

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.

[Bob Dingley]

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

[champ driver]

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?

Does it really matter that much between statute or nautical, there's not that much difference between the two.

[1600vw]

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.

[Dana]

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.

You're not announcing "5 miles out" for the benefit of those on the ground; you're announcing it so that another guy who may be 5-1/2 miles out knows to look for you.

[Frank Giger]

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.

:)

[kdahlhaus]

Thanks everyone - just trying to learn the distances from the local airport appropriately.

[Mike M]

... By the time I reached the airfield someone had taken it....

Taken the airfield? Where? What do ya s'pose they did with it?

(not what you meant, but tickled my funnybone, thanks :)

[gbrasch]

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

Thanks for a good chuckle!

[FlyingRon]

Radio reports should be done in NM.

Amusingly, while class D are nominally sized at 4.2 NM, this odd number stems from the fact that the old Airport Traffic Areas (which by the way were not controlled airspace nor charted) were 5SM. Even more oddly. Someone botched the conversion. 5 SM is slightly over 4.3 NM

[Frank Giger]

I get a good chuckle out of distances from the airport, as without a time they can be meaningless.

"Talladega traffic, Cardinal XYZ is ten miles west, landing on 22, entering the downwind across the airport, Talledega" is a correct call, but unless one knows what a Cardinal is, the "when" of his arrival is a mystery.

Throw in experimentals and it's hilarity.

"Talledega traffic, Nieuport 2GV is ten miles west, landing on 22, entering the downwind across the airport, Talledega" has often been met with a "Nieuport, what is your location" five minutes later, as someone is wondering if they can safely take off.

The Cardinal would probably say "turning base to final" about that time. Me, I'm still five miles out. Or maybe seven, putt putting along at 55 mph.

The whole purpose of calling out location and intentions to the traffic is to aid in "seek and avoid," so it's a good idea to know approximate time one will travel ten miles.

Plus, when one is in the air it's an approximation. If one calls at ten miles, by the time it's heard and understood one is closer than that.

[rwanttaja]

Throw in experimentals and it's hilarity.

"Talledega traffic, Nieuport 2GV is ten miles west, landing on 22, entering the downwind across the airport, Talledega" has often been met with a "Nieuport, what is your location" five minutes later, as someone is wondering if they can safely take off.

"Auburn Traffic, Fly Baby 848 entering downwind behind the 172, Auburn."

(Apparent Student in the 172) "Fly Baby, do I need to do a 360 so you can get by me?"

Told him I'd just throttle back a bit.


Plus, when one is in the air it's an approximation. If one calls at ten miles, by the time it's heard and understood one is closer than that.
Another bit of fun 'n games is the term, "over", as in "above." I say I'm over a landmark when said landmark disappears beneath the leading edge. Others seem to use it when the landmark is over the horizon.

Ron Wanttaja

[Frank Giger]

Another bit of fun 'n games is the term, "over", as in "above." I say I'm over a landmark when said landmark disappears beneath the leading edge. Others seem to use it when the landmark is over the horizon.

You just described more than one of my relationships with women back in my youth.

[Arrius]

What if you are landing to a country that is using the metric system? Do they communicate in miles or nautical miles as well? I am asking out of curiosity.

[martymayes]

What if you are landing to a country that is using the metric system? Do they communicate in miles or nautical miles as well? I am asking out of curiosity.

ICAO uses nautical miles as the standard. I'm pretty sure the other 190 member countries use ICAO standards?

[Arrius]

ICAO uses nautical miles as the standard. I'm pretty sure the other 190 member countries use ICAO standards?

Indeed, just checked the data archive of ICAO, they do use miles. Thanks for clarifying.

[FlyingRon]

We used to have a controller at CHO who used to argue with pilots about the distance they were from the airport. She was a hoot.

African or European?