Anonymous
Anonymous asked in Cars & TransportationAircraft · 10 years ago

Private pilot exam practice question, VFR visibility mins?

This question is bugging me, I'm acing the practice tests but I still disagree with this one:

"The minimum flight visibility required for VFR flights above 10,000 feet MSL and more than 1,200 feet AGL in controlled airspace is"

choices are like 1, 3, and 5 SM. Answer is 5.

The explanation wasn't really helpful. Here's what I figured: The AGL number doesn't matter in controlled airspace, it only comes into play in class G airspace. If you're above 10,000 MSL in a class E, then the minimum visibility is 5 SM. In a class B, C, or D, though, it doesn't matter what altitude MSL you're at, in class B it's 3 miles and clear of clouds, in class C and D it's 3 miles and 500 below, 1000 above, 2000 horizontal. Always 3 miles.

So I figure welp you can have a class B, C, or D airport that meets the > 10,000 MSL requirement, and be more than 1200 feet above the ground but in its airspace, so since 3 is less than 5, the minimum visibility is 3!

Update:

Yes, E is controlled, and greater than 10,000 MSL in class E has a minimum visibility of 5 miles. The question does not ask that though, it asks for minimum visibility in controlled airspace. Class B, C, and D airports have no rules against being built at high elevations, you could have, for example, a class C airport at 9500 feet MSL, with its airspace going up to like 13500 MSL. So you could be in class C and therefore have the 3 mile limit yet be above 10k MSL and 1200 AGL.

Update 2:

Thanks Joel, I think you understand where I'm coming from the most.

However, you're still saying to go with the situation it is giving me. It's not giving me a clearly defined situation, you're admitting that yourself. The question wants you to assume they mean class E because they bring up the 10,000 feet MSL, but the 10,000 feet MSL doesn't necessarily make it a class E, as you yourself pointed out.

Relevance
• Anonymous
10 years ago

You're just supposed to memorize the answers for those tests. No one can honestly differentiate between 3 and 5 miles visibility, so it doesn't really matter.

• 10 years ago

When they say the "minimum visibility", they don't mean the minimum that could apply under any circumstances. They mean the minimum that applies for just the circumstances given.

You could have a class B, C, or D airport. And in that case, the minimum might be 3 miles. But this is the minimum the minimum could be. That's not what the question asks. The question asks what the minimum *is*, not what the lowest the minimum could be is.

"So you could be in class C and therefore have the 3 mile limit yet be above 10k MSL and 1200 AGL."

Sure, you *could*. But the question doesn't ask what the minimum *could* be under any conceivable circumstances you might imagine that are consistent with those in the question. It asks what the minimum *is* under only the circumstances *given* in the question.

• John R
Lv 7
10 years ago

First, the AGL DOES matter for class E - Class E starts at ether 1200 AGL or 700 AGL in a transition area. It's only outside of class E that the AGL rule does NOT matter.

No where in the question does it mention class B, C, or D airspace, which would represent a minuscule amount of the airspace above 10,000 ft.

• John
Lv 7
10 years ago

According to FAR 91.155, it specifically says 5 mi for this case. Remember that E is controlled airspace as well.