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

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?

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.

On Mon, 27 Jun 2005 23:15:06 GMT, john smith wrote in
::

What requirements are there for flying BELOW the airport surface?

I would think you'd need some digging equipment. :-)

There is also a speed issue when inside the 30 mile radius of the Class
Bravo primary. FAR 91.117 covers that..."No person may operate an aircraft
in the air space underlying a Class B airspace area designated for an
airport or in a VFR corridor designated through such a Class B airspace
area, at an indicated airspeed of more than 200 knots.

Fred


"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

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?

I would say that if you chose to go down that path of picking at cracks in
the definitions, don't be surprised when the crack opens up and sh*ts all
over you. g
--
Jim in NC

"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..."

The airspace isn't defined by reference to the airport altitude. An airspace
that goes down to the surface goes down to the surface at each point in that
airspace; otherwise, it would say e.g. "airport elevation to 2600" rather
than "surface to 2600".

--Gary

My Cherokee 140 won't even do 140 kts (unless I'm out back pushing it
while in a tailwind and descending g)



Fred Choate wrote:
There is also a speed issue when inside the 30 mile radius of the Class
Bravo primary. FAR 91.117 covers that..."No person may operate an aircraft
in the air space underlying a Class B airspace area designated for an
airport or in a VFR corridor designated through such a Class B airspace
area, at an indicated airspeed of more than 200 knots.

Fred