Q: Flying BENEATH Class B/C/D Airspace

The regs say you must communicate, have permission, a clearance, have a
transponder, etc to fly in any Class B/C/D Airspace.
The airspace is generally defined by the airport reference point
altitude and location on the field. For example the definitions state
"from the surface to..."
What requirements are there for flying BELOW the airport surface?
I know several airports with the requisite airspace that are located
above surrounding terrain where it would be possible to fly below the
airport surface.
What say the group?

What requirements are there for flying BELOW the airport surface?

A propeller strong enough to dig through the asphalt?



"john smith" wrote in message
...
The regs say you must communicate, have permission, a clearance, have a
transponder, etc to fly in any Class B/C/D Airspace.
The airspace is generally defined by the airport reference point
altitude and location on the field. For example the definitions state
"from the surface to..."
What requirements are there for flying BELOW the airport surface?
I know several airports with the requisite airspace that are located
above surrounding terrain where it would be possible to fly below the
airport surface.
What say the group?

"john smith" wrote in message
...
The regs say you must communicate, have permission, a clearance, have a
transponder, etc to fly in any Class B/C/D Airspace.
What requirements are there for flying BELOW the airport surface?
What say the group?

To fly BELOW the airport surface is never recommended. Cumulo granite could
ruin your day

I fly out of an airport that is near a Class C with a bottom of 1400....just
stay below that and there's not a problem. Further down the road is a
conglomeration of airspace, but if I stay above 1100, but below 1800.....you
get the picture. This technique is probably more trouble than would be
worth to plan if you were just passing through, but for the local folks it
works well.

Later,

Stephen
Foley, Alabama

On Mon, 27 Jun 2005 18:27:47 -0500, "Hotel 179"
wrote:

To fly BELOW the airport surface is never recommended. Cumulo granite could
ruin your day

Lebanon NH airport is located on a ridge or butte. It would indeed be
possible to fly below the RUNWAY surface, but of course that's not
what the Class D requirement suggests. It extends from the surface of
the ground at any point to 2,500 feet (whatever) above that surface.
So I reckon that in the case of Lebanon, the top of the Class D tuna
can would be rippled: higher where the airport itself is situatated.


-- all the best, Dan Ford

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Cub Driver wrote:

On Mon, 27 Jun 2005 18:27:47 -0500, "Hotel 179"
wrote:

To fly BELOW the airport surface is never recommended. Cumulo granite could
ruin your day

Lebanon NH airport is located on a ridge or butte. It would indeed be
possible to fly below the RUNWAY surface,
Or at least below the altitude of the runway surface.g

You can also fly below the altitude of the Leadville runway surface.
The only question is how close a proximity you are to said runway.
--
Alex -- Replace "nospam" with "mail" to reply by email. Checked infrequently.

"Cub Driver" wrote in message
...
[...]
So I reckon that in the case of Lebanon, the top of the Class D tuna
can would be rippled: higher where the airport itself is situatated.

The airspace is not "rippled". The maximum elevation is generally 2500 feet
above the *airport*, even as the airspace itself extends to the surface,
wherever that surface may lie.

On Tue, 28 Jun 2005 11:24:21 -0700, "Peter Duniho"
wrote:

The airspace is not "rippled". The maximum elevation is generally 2500 feet
above the *airport*, even as the airspace itself extends to the surface,
wherever that surface may lie.

Point taken.

I will remember that, the next time I am coasting over the Delta
airspace.


-- all the best, Dan Ford

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We have just the situation you describe at Seattle-Tacoma Airport...it sits
on high ground adjacent to Puget Sound. On the sectional, just west of the
"all the way to the ground" portion of the Class B, there is a blue square
with "-30" in it, and the legend says "Minus ceiling value indicates surface
up to but not including that value." The surface it refers to is the water.
Ergo, the Class B goes all the way to the water, and you can't fly past SEA
at 500 feet above the water without a Class B clearance.

Paine Field's Class D does not have a similar graphic, but its airspace
extends over Puget Sound and I'm guessing that the same reasoning applies.
Note that AIM 3-2-5 says that Class D "generally extends from the surface to
2500 feet above airport elevation," thus making a distinction between the
surface and field elevation.

Bob Gardner

"john smith" wrote in message
...
The regs say you must communicate, have permission, a clearance, have a
transponder, etc to fly in any Class B/C/D Airspace.
The airspace is generally defined by the airport reference point altitude
and location on the field. For example the definitions state "from the
surface to..."
What requirements are there for flying BELOW the airport surface?
I know several airports with the requisite airspace that are located above
surrounding terrain where it would be possible to fly below the airport
surface.
What say the group?

On Mon, 27 Jun 2005 16:51:59 -0700, "Bob Gardner"
wrote:

Note that AIM 3-2-5 says that Class D "generally extends from the surface to
2500 feet above airport elevation," thus making a distinction between the
surface and field elevation.

Ah! Okay, scratch my presumption that the roof of the Delta airspace
might be rippled



-- all the best, Dan Ford

email (put Cubdriver in subject line)

Warbird's Forum: www.warbirdforum.com
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the blog: www.danford.net
In Search of Lost Time: www.readingproust.com

Assuming you mean 'below the airspace'

Well, for one... there's the mode C veil. 30 miles from the primary
airport located in class bravo, mode C transponders are required and
must be transmitting altitude data.