Descent below MDA -- what would you do?

"Ron Rosenfeld" wrote in message ...
On Mon, 15 Aug 2005 08:39:15 -0400, Roy Smith wrote:

Ron Rosenfeld wrote:
How does it improve the legal situation to cancel IFR when you are still
IMC? (You mentioned visibility of 2 1/2 miles).

I my original post, I said something like "reports of 2-1/2 to 4, assume
2-1/2". In a followup, I asked people to ignore that assumption and
consider accept the possibility that it might be 3. My apologies if I
confused the issue with this pair of contradictory statements.

I confuse easily these days g.

But assuming you were legal to cancel IFR, and wanted to do so, could you
not contact FSS through one of the relatively close VOR's, and cancel that
way? Or are they, too, out of radio reception range at that altitude? I
note HUO or CMK might be within range.


On 2 1/2 mile final in such conditions I'm not going to be trying to get through to FSS. ATC maybe, since
they're frequency is still on my "flip-flop".

But then again if I'm on 2 1/2 mile final and the visibility is 3 miles (VFR), then I can see the runway, so
yeah, I'm gonna come down and land... Conversely, if I can't see the runway then I am concluding that the
visibility is not 3 miles
--
Cheers,
John Clonts
Temple, Texas
N7NZ

On Tue, 16 Aug 2005 02:11:06 GMT, "John Clonts"
wrote:

On 2 1/2 mile final in such conditions I'm not going to be trying to get through to FSS. ATC maybe, since
they're frequency is still on my "flip-flop".

The OP has already written that he is "long out of radar and radio contact
with ATC." So contacting ATC directly is not an option.

But then again if I'm on 2 1/2 mile final and the visibility is 3 miles (VFR), then I can see the runway, so
yeah, I'm gonna come down and land... Conversely, if I can't see the runway then I am concluding that the
visibility is not 3 miles

As I previously wrote, I would not cancel either and I certainly would not
descend below MDA without having the requisite 91.175 items in view.

But the OP was posing a hypothetical in which he wanted to descend below
MDA; in this hypothetical he was in VMC conditions, but still on an IFR
flight plan.

So far as contacting FSS to cancel IFR when in VMC, it's no big deal (so
long as you have the airport in sight). I frequently try to do that
returning to my home base where there is no radio contact with ATC below
about 4000' (airport at 40' MSL). Of course, my home base rarely has
traffic.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

You're 2 miles from YARNN at the MDA and have good ground
contact ahead and
to both sides. You can also see the ridgeline east of the final approach
course which is represented by the 1850 elevation marker. What
you don't see is the runway, or any of the other things called out in
91.175(c)(3).

Who else besides you knows what you can and can't see? Are you certain
you can't see it?

Once upon a time, you were allowed to descend based on seeing a
landmark that was familiar to you. This reflected the reality of how
people really do thins, so of course it's not legal any longer - but
that doesn't mean it's not done. My home field (EYQ) is pretty hard to
spot, but there is a factory on the downwind-to-base turn for Rwy 9
that sticks out like a sore thumb. It's been years since Wyman-Gordon
actually owned it, but Wyman-Gordon it remains for generations of
student pilots - and when they become instrument students and learn to
shoot the NDB or GPS, it's what they learn to look for. Once you see
that, you know exactly where the runway is. Are you sure you can't see
it? I bet you can just make it out in the haze.

You know from experience that this is a difficult
airport to spot even in good VFR because it blends in with the
surrounding terrain.

Sure it does. But if you know where to look, you can just see it
outlined in the haze.

Continuing your descent
below the MDA, but staying above the VNAV glideslope it technically not
legal, but seems like a "no harm, no foul" kind of violation.

You know, this question has a lot in common with another one being
discussed on r.a.piloting (Illegal charters - google for it - it's the
usual private pilot compensation thing). You know the chance of
getting busted on it is zero. You also know that there are rules
against it - and that these rules are in place for good reasons - but
they could't possibly be in place to keep you from doing this, because
this clearly isn't dangerous.

There are reasons why you're not supposed to descend based on a
landmark that is familiar to you. In general, they are good reasons.
When you pick out a landmark in the fog and mist, coming in on an NDB
approach with no distance and iffy course guidance, it's all too easy
to believe that new dairy barn is actually Farmer Brown's old barn, and
put yourself into the highway (or worse) instead of the runway.

Once again, it boils down to this - is it ever OK to substitute your
own judgment for the rules. It's a yes or no answer. Either you
always drive at or below the speed limit, come to a full stop at every
red light and stop sign before turning right, never fly one pound
overgross, never accept a clearance contrary to the FAR's, etc. - or
you use your best judgment, and sometimes decide that the rule can be
bent.

So ask yourself this - what makes it OK to accept a clearance you know
is improper to avoid being sent to the back of the line, but not OK to
decend here?

Michael

I don't beleive weather reporting is a requirement for Special VFR per
FAR 91.157.

"gman" wrote in message
oups.com...

I don't beleive weather reporting is a requirement for Special VFR per
FAR 91.157.


Special VFR exists only in a surface area, weather reporting is a
requirement for a surface area.

Steven,
Could you point me to correct FAR paragraph? A quick search of the
part 91 FARs on AOPA's website did not turn up anything supporting your
statement.

Thanks

"gman" wrote in message
oups.com...

Steven,
Could you point me to correct FAR paragraph? A quick search of the
part 91 FARs on AOPA's website did not turn up anything supporting your
statement.


Which statement? That Special VFR exists only in a surface area or that
weather reporting is a requirement for a surface area?

For both.

"gman" wrote in message
ups.com...

For both.



FAR 91.155(c) states, " Except as provided in §91.157, no person may operate
an aircraft beneath the ceiling under VFR within the lateral boundaries of
controlled airspace designated to the surface for an airport when the
ceiling is less than 1,000 feet." That refers to a surface area.

From the Pilot/Controller Glossary:

SURFACE AREA- The airspace contained by the lateral boundary of the Class B,
C, D, or E airspace designated for an airport that begins at the surface and
extends upward.


The procedures for establishing surface areas are found in FAA Order 7400.2,
"Procedures for Handling Airspace Matters". There are two requirements that
must be met prior to establishing a surface area:

1.) Communications capability with aircraft must exist down to the runway
surface of the primary airport either directly with ATC or by rapid relay
through another communications facility which is acceptable to ATC, such as
a FSS.

2.) Weather observations must be taken at the primary airport during the
time of designation of the surface area.

"Steven P. McNicoll" wrote:
From the Pilot/Controller Glossary:
SURFACE AREA- The airspace contained by the lateral boundary of the Class B,
C, D, or E airspace designated for an airport that begins at the surface and
extends upward.

I probably should know this, but now that I (re-)read the above, I see that
there's several ways to parse that sentence with respect to B and C
airspace:

1) Only the inner cylinder that touches the surface is the surface area,
i.e. SVFR is not available in the outer rings of B/C airspace.

2) The boundaries of the surface area are exactly the same (vertical and
lateral) as the B/C airspace. This is what I had always assumed.

3) The surface area includes all the airspace from the edge of the
outermost ring projected down to the surface. This would be extremely
illogical, but it is one possible parsing.

Which is correct?

Is there such a thing as B, C, or D airspace in the US which is not
"designated for an airport"?