What do those negative numbers in the segmented box mean?

[RobertE]

I flew into Scottsdale, AZ this past weekend and had to stay out of Luke AFB airspace while remaining below Phoenix Bravo.  Not a problem except for the confusion I suffered due to some of the indications on the Phoenix Terminal Area chart.  I you examine it you'll see a few areas - Class D, pretty much - in which a segmented box has a negative number inside of it (say, -30 or -40). 

 

So what are those negatives indicating?

 

Thanks.

 

 

[midlifeflyer]

You talking about the Class D altitudes like the -40 in the segmented box in the Scottsdale Class D? It means that the Class D airspace starts at the surface and goes up to but does not include (that's what the minus part means)  4000'

 

I you have the chart, it's in the legend.

 

Always kind of wondered about that, like I'd be able to maintain 3999.5'

[Ragsf15e]

I checked it out on skyvector. Look on the legend, it says "minus values indicate surface up to but not including the value."

Looks like exciting airspace. When i go vfr places like that, I will usually be on flight following and ask for permission to enter the class B even if there's a way to get to the destination without. That at least gets you legal even if you stay out of it. Controllers really have been good with it.

[Mooneymite]

That's the number of points you lose if you get shot down by friendly fire.....

[RobertE]

Thanks, gentlemen.  Now that I'm reliant on Foreflight I don't know where to look for those chart legends.  Actually, I suppose I ought to figure that out tonight.

[midlifeflyer]

Thanks, gentlemen.  Now that I'm reliant on Foreflight I don't know where to look for those chart legends.  Actually, I suppose I ought to figure that out tonight.

 

Check Foreflight "Documents"

[smccray]

I flew into Scottsdale, AZ this past weekend and had to stay out of Luke AFB airspace while remaining below Phoenix Bravo.  Not a problem except for the confusion I suffered due to some of the indications on the Phoenix Terminal Area chart.  I you examine it you'll see a few areas - Class D, pretty much - in which a segmented box has a negative number inside of it (say, -30 or -40). 

 

So what are those negatives indicating?

 

Thanks.

 

I looked at that chart last year when I flew to Phoenix.  I decided to go IFR just for that reason.  ATC took me straight over Sky Harbor headed north into a right base for RW 7R.  I made an IFR departure essentially on the same course.