Class G to 14,500ft

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bigblockz8

Pre-takeoff checklist
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Why does class G extend up to 14,500ft? I asked a few AGI's/IGI's/CFI's but they all say terrain. Why protect terrain? Any other reason(s)?
 
Terrain clearance and radar coverage when off airways.
 
bigblockz8 said:
Thanks! I never would have thought of that
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welcome - it's pretty obvious when flying out west. Airways are protected...after that it's pretty much a free-for-all. I've gotten pop-ups and gone high rather than gone IFR in G. Denver center has been very cooperative to their credit. Can't say enough good things about Denver Center on this one.
 
Before it was Class G, the 14,500 was the floor of the Continential Control Area.
 
BillTIZ said:
Before it was Class G, the 14,500 was the floor of the Continential Control Area.
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...and it has nothing to do with radar coverage, although I think it has something to do with the highest terrain in the Continenatal United States.
 
Mt. Whitney, CA is 14505 MSL. To clear all the terrain, 14500 isn't quite enough....

The sectional shows it at 14491, but the USGS (who actually measures such things) disagrees.
 
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bigblockz8 said:
Why does class G extend up to 14,500ft? I asked a few AGI's/IGI's/CFI's but they all say terrain. Why protect terrain? Any other reason(s)?
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I think you're looking at this from the wrong end. Class G airspace doesn't extend up to 14,500 MSL, Class G is what remains after controlled airspace is established. Class E airspace over the contiguous US is established with a floor of 14,500 MSL, excluding the airspace below 1,500' AGL. We don't establish controlled airspace to protect terrain, we establish it to protect airplanes.
 
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MAKG1 said:
Mt. Whitney, CA is 14505 MSL. To clear all the terrain, 14500 isn't quite enough....

The sectional shows it at 14491, but the USGS (who actually measures such things) disagrees.
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The airspace below 1,500 feet above the surface of the Earth is excluded.
 
Ron Levy said:
...and it has nothing to do with radar coverage, although I think it has something to do with the highest terrain in the Continenatal United States.
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While many say it's due to the highest terrain in the contiguous US I have my doubts. I've never found anything concrete that makes that connection and it doesn't actually clear all of the terrain.

The Continental Control Area was established in 1957 at 24,000 feet. In 1961 the FAA established an intermediate airway system for the altitudes between 14,500 and 24,000 MSL, the Continental Control Area was lowered to 14,500 MSL at that time. In 1964 the intermediate airways were dropped, the division between the low and high airway systems became 18,000 MSL. No change was made to the Continental Control Area.

I think the 14,500 MSL altitude is simply one of the last vestiges of the very brief existence of the intermediate airway system. These system altitudes also appear in VOR service volumes.
 
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