CFI Pop Quiz #103

[Chris Burgess]

During operations within controlled airspace at altitudes of more than 1,200 feet AGL, but less than 10,000 feet MSL, the minimum horizontal distance from clouds requirement for VFR flight is

A) 1 mile
B) 2,000 feet
C) 1,000 feet

[bartc150]

I'll say A.

[chuter]

I'll go with B.

1000 above, 500 below, 2000 horizontal.

[iconnary]

B as well.

[mark treidel]

During operations within controlled airspace at altitudes of more than 1,200 feet AGL, but less than 10,000 feet MSL, the minimum horizontal distance from clouds requirement for VFR flight is

A) 1 mile
B) 2,000 feet
C) 1,000 feet

FAA 91.155 basic VFR weather minimums
in controlled air space (b, c, d) with flight visibility of 3 statute miles is:
class B, clear of clouds
class C & D is 500' below
1000' above
2000' horizontal
class E is the same under 10,000 and is also controlled A/S.
(edited for correction)
The correct answer is "B".

[GyroRon]

I can't remember. Thank goodness I go for Biannual later this month! My gut says it is A, but I am also thinking it could very well be B.

[ventana7]

Ron
The trick I use to remember them is 5-10-20.

Then remember that a jet will be climbing faster than descending so you only need the 500 below but the 1000 above- that leaves the 2000 for horiz.
The 5-10-20 covers most of the airspace except B,G, G nite and above 10,000'


Chris- these are a real service to the forum members-- keep em comin.

[Chris Burgess]

B is correct. Post #5 said that Class E was uncontrolled, not so. Class E does not require communications but it is controlled airspace. Look in 14 CFR Part 1 for the definition of "Controlled Airspace"

Rob... I liked "3-152's" refering to Cessna 152's. Translated as, 3 miles visibility, 1000 feet above, 500 feet below, and 2000 feet horizontally.

Bonus question: Why 500 below and 1000 above?

[Harry_S.]

Because of ascending and descending traffic?!


Cheers :)

[automan1223]

Well you need 500 below which leaves a 1000' ceiling VFR.
500' is usually the minimum altitude that you should safely operate over sparsely populated areas. Of course you have that catch all minimum altitude that applys to all rotorcraft that says can land safely in the event of a power failure....

A ceiling is anything reported that is OVC Overcast Or BKN Broken.

Jonathan

[Chris Burgess]

Well I'll explain with what I was told by an Examiner. If you have ever noticed, cloud bases are usually pretty well defined. So 500 below is fine. But the tops are usually not so well defined, hard to tell just where the top is. Hence, 1000 feet above. Not really a climb/descent issue at all.

[Jazzenjohn]

Thanks Chris, I agree with Rob. This is good for us, and please keep them coming!

[Harry_S.]

Will throw this out there there to stimulate the grey matter.

Ascending aircraft are *usually* at a VSI of 1000. It could see the traffic at 500 below cloud and avoid. when going thru and exiting cloud it could see the traffic at 1000 above cloud and avoid.

Descending aircraft are *usually* at a VSI of 500. It could see the traffic at 1000 above cloud and avoid. When exiting cloud it could see the traffic at 500 below cloud and avoid.

The S/L traffic above or below could see the ascending or descending traffic in his view and avoid.

Make any sense?!;)


Cheers :)