Flying under IMC

Hi,
i'm asking myself to make an Instrument Rating or not.
There are some questions to IFR-Pilots :

... when flying under a flight plan (IFR) can i fly routes at my choice ?
e.g. take-off under IMC, enroute 10 min under IFR (clouds), 30 min VFR on
top, descending to my destination under IMC (through cloúds), landing
at destination under VMC (below the lower layer of clouds)

... when reaching IMC after 30 min. VMC ("round trip under VFR") do i have
to file a flight plan (IFR) or am i able to fly only by reference to the
instruments through an e.g. 300 ft Layer of clouds and after that, when
reaching "On Top" fly again under VFR ?

Peter

"Peter Bauer" wrote in message
om...
Hi,
i'm asking myself to make an Instrument Rating or not.
There are some questions to IFR-Pilots :

[scenarios about flying in VMC under VFR between IFR segments snipped]

You can switch back and forth between IFR and VFR if you want but you may it
inconvenient, since every time you want to go back to IFR, you need to
obtain the necessary clearance from ATC (assuming not in Class G
airspace...in controlled airspace, you must have an ATC clearance and an IFR
flight plan in order to fly in IMC, even briefly). There is a way to file a
mixed IFR/VFR flight plan, but I've never heard of that being used when you
need IFR at both the departure and arrival ends of the flight.

Typically, if you're flying under IFR, find yourself in VMC and want to take
advantage of that to operate under the flexibility of VFR, you'd get a "VFR
on top" clearance. That's an IFR clearance, and you would still be
operating under IFR, but you usually would get the flexibility of choosing
your routing and altitude as if you were VFR (and in fact would have to fly
the +500' VFR cruising altitudes rather than the even thousands IFR cruising
altitudes).

For example, taking your first scenario, done this way, you'd take off in
IMC, arrive at VMC above the clouds, get a "VFR on top" clearance, fly in
VMC using VFR altitudes and procedures for 30 minutes, and then descend back
to your destination through IMC for the landing, possibly flying a full
instrument approach.

Your flight plan would be for the entire flight, you'd be flying under IFR
for the entire flight, but the time during which you were flying with a "VFR
on top" clearance, you'd be able to get most of the advantage you'd get had
you cancelled IFR and flown VFR for that period.

Something to keep in mind that some new instrument pilots forget: "VFR on
top" does not require that there be IMC below you. It can be used any time
you can maintain VMC. If you're cruising along IFR, but there's not a cloud
for 100 miles and ATC starts vectoring you around or slowing you down or
gives you a hold, often you can use the "VFR on top" clearance to resolve
whatever issue ATC had, and allow yourself to proceed directly to whereever
you were headed.

Basically, when IFR procedures become inconvenient and VMC prevails, "VFR on
top" allows you to practically fly VFR without giving up your IFR clearance.

Pete

Peter Duniho wrote:

the "VFR on top" clearance to resolve
whatever issue ATC had, and allow yourself to proceed directly to
whereever you were headed.

Is that likely to work? ATC may, after all, deny the "on top" clearance.

- Andrew

On 28 Jun 2004 12:11:27 -0700, (Peter Bauer)
wrote:

Hi,
i'm asking myself to make an Instrument Rating or not.
There are some questions to IFR-Pilots :

.. when flying under a flight plan (IFR) can i fly routes at my choice ?

You have to submit a route when you file the IFR plan. In flight, you
can request changes to the route but it is nowhere the flexibility of
VFR.

e.g. take-off under IMC, enroute 10 min under IFR (clouds), 30 min VFR on
top, descending to my destination under IMC (through cloúds), landing
at destination under VMC (below the lower layer of clouds)

This is very common and typically would be accomplished entirely on an
IFR flightplan. The exception would be if VMC conditions exist below
the cloud layer at the destination, which would allow a visual
approach, or cancel IFR and complete the flight as VFR.

.. when reaching IMC after 30 min. VMC ("round trip under VFR") do i have
to file a flight plan (IFR) or am i able to fly only by reference to the
instruments through an e.g. 300 ft Layer of clouds and after that, when
reaching "On Top" fly again under VFR ?

In the States, in class G airspace, you can fly IFR without a
clearance. Fortunately, class G is the exception, and pretty much
everywhere else, a clearance is required to fly IFR.

-Nathan

You can switch back and forth between IFR and VFR if you want but you may it
inconvenient, since every time you want to go back to IFR, you need to
obtain the necessary clearance from ATC (assuming not in Class G
airspace...in controlled airspace, you must have an ATC clearance and an IFR
flight plan in order to fly in IMC, even briefly). There is a way to file a
mixed IFR/VFR flight plan, but I've never heard of that being used when you
need IFR at both the departure and arrival ends of the flight.


But what ...when descending under VMC into Class G Airspace and then
coming into IMC "wheather" (e.g. fog,..) then i can fly IFR without a
clearance ???
If a second pilot does the same "plan" .... very dangerous, isn't it ?
Nobody knows from each other flying in fog...


Typically, if you're flying under IFR, find yourself in VMC and want to take
advantage of that to operate under the flexibility of VFR, you'd get a "VFR
on top" clearance. That's an IFR clearance, and you would still be
operating under IFR, but you usually would get the flexibility of choosing
your routing and altitude as if you were VFR (and in fact would have to fly
the +500' VFR cruising altitudes rather than the even thousands IFR cruising
altitudes).

i can really fly VFR under an IFR-Flight Plan ??
But probably with the same "squawk" as under IFR ?
...and then after getting "tired" flying VFR ..changing back to the
initial IFR Flight Plan ? (what is when too far away under VFR flying
from the "filed" Plan ???
Does ATC give me then another "Plan", an "abbreviated" Flight Plan ?



For example, taking your first scenario, done this way, you'd take off in
IMC, arrive at VMC above the clouds, get a "VFR on top" clearance, fly in
VMC using VFR altitudes and procedures for 30 minutes, and then descend back
to your destination through IMC for the landing, possibly flying a full
instrument approach.

Your flight plan would be for the entire flight, you'd be flying under IFR
for the entire flight, but the time during which you were flying with a "VFR
on top" clearance, you'd be able to get most of the advantage you'd get had
you cancelled IFR and flown VFR for that period.

Something to keep in mind that some new instrument pilots forget: "VFR on
top" does not require that there be IMC below you. It can be used any time
you can maintain VMC. If you're cruising along IFR, but there's not a cloud
for 100 miles and ATC starts vectoring you around or slowing you down or
gives you a hold, often you can use the "VFR on top" clearance to resolve
whatever issue ATC had, and allow yourself to proceed directly to whereever
you were headed.


Well, i haven't known about this......because i'm only an PP-ASEL
without
IFR-Privileges. But the described possibilitites makes it very
interesting getting an IFR-Pilot ;-)



Basically, when IFR procedures become inconvenient and VMC prevails, "VFR on
top" allows you to practically fly VFR without giving up your IFR clearance.

Pete


Thanks to you...Pete


Peter

You can switch back and forth between IFR and VFR if you want but you may it
inconvenient, since every time you want to go back to IFR, you need to
obtain the necessary clearance from ATC (assuming not in Class G
airspace...in controlled airspace, you must have an ATC clearance and an IFR
flight plan in order to fly in IMC, even briefly). There is a way to file a
mixed IFR/VFR flight plan, but I've never heard of that being used when you
need IFR at both the departure and arrival ends of the flight.


But what ...when descending under VMC into Class G Airspace and then
coming into IMC "wheather" (e.g. fog,..) then i can fly IFR without a
clearance ???
If a second pilot does the same "plan" .... very dangerous, isn't it ?
Nobody knows from each other flying in fog...


Typically, if you're flying under IFR, find yourself in VMC and want to take
advantage of that to operate under the flexibility of VFR, you'd get a "VFR
on top" clearance. That's an IFR clearance, and you would still be
operating under IFR, but you usually would get the flexibility of choosing
your routing and altitude as if you were VFR (and in fact would have to fly
the +500' VFR cruising altitudes rather than the even thousands IFR cruising
altitudes).

i can really fly VFR under an IFR-Flight Plan ??
But probably with the same "squawk" as under IFR ?
...and then after getting "tired" flying VFR ..changing back to the
initial IFR Flight Plan ? (what is when too far away under VFR flying
from the "filed" Plan ???
Does ATC give me then another "Plan", an "abbreviated" Flight Plan ?



For example, taking your first scenario, done this way, you'd take off in
IMC, arrive at VMC above the clouds, get a "VFR on top" clearance, fly in
VMC using VFR altitudes and procedures for 30 minutes, and then descend back
to your destination through IMC for the landing, possibly flying a full
instrument approach.

Your flight plan would be for the entire flight, you'd be flying under IFR
for the entire flight, but the time during which you were flying with a "VFR
on top" clearance, you'd be able to get most of the advantage you'd get had
you cancelled IFR and flown VFR for that period.

Something to keep in mind that some new instrument pilots forget: "VFR on
top" does not require that there be IMC below you. It can be used any time
you can maintain VMC. If you're cruising along IFR, but there's not a cloud
for 100 miles and ATC starts vectoring you around or slowing you down or
gives you a hold, often you can use the "VFR on top" clearance to resolve
whatever issue ATC had, and allow yourself to proceed directly to whereever
you were headed.


Well, i haven't known about this......because i'm only an PP-ASEL
without
IFR-Privileges. But the described possibilitites makes it very
interesting getting an IFR-Pilot ;-)



Basically, when IFR procedures become inconvenient and VMC prevails, "VFR on
top" allows you to practically fly VFR without giving up your IFR clearance.

Pete


Thanks to you...Pete


Peter

If a second pilot does the same "plan" .... very dangerous, isn't it ?
Nobody knows from each other flying in fog...


Yes. That is the purpose of controlled airspace - to prevent such things by
ensuring that everyone in there under IFR is being separated. Flying IFR in
uncontrolled airspace is not all that prudent, and fortunately not necessary in
most of the US.

Most airports have controlled airspace surrounding them to the ground for the
purpose of instrument approaches.

Jose




--
(for Email, make the obvious changes in my address)

Is that likely to work?

I fly IFR into Ontario, California IFR on my run and do it VFR on top as much
as possible. It cuts down on our run time as we fly a more direct route, and
since we are on a schedule it helps a lot.

ATC may, after all, deny the "on top" clearance.

They can, but unlikely. It frees up the controller to focus on other things.





-John
*You are nothing until you have flown a Douglas, Lockheed, Grumman or North
American*

"Peter Bauer" wrote in message
om...

.. when flying under a flight plan (IFR) can i fly routes at my choice ?
e.g. take-off under IMC, enroute 10 min under IFR (clouds), 30 min VFR
on
top, descending to my destination under IMC (through cloúds),
landing
at destination under VMC (below the lower layer of clouds)

.. when reaching IMC after 30 min. VMC ("round trip under VFR") do i have
to file a flight plan (IFR) or am i able to fly only by reference to
the
instruments through an e.g. 300 ft Layer of clouds and after that,
when
reaching "On Top" fly again under VFR ?

You do not say where you are flying, Peter. Others have answered on the
assumption that you are flying in the US, I'll give you an answer for
Germany.

The airspace system in Germany is not very different to that in the US, but
there are a couple of differences. Controlled airspace generally starts at
2500 ft agl rather than 1200 ft agl. Flying under IFR in class G is
forbidden in Germany. Thus for an IFR flight, if your destination is not an
IFR airport surrounded by controlled (or class F) airspace, you usually need
to be able to cancel IFR by the minimum instrument altitude which is not
below 2500 ft. This makes IFR flights to VFR airports fairly painful.

To fly under IFR you need a clearance. Pop-up IFR clearances (if you find
IMC on a VFR flight like your second scenario) are troublesome. I've had to
dictate an entire flight plan (including the colour of the dinghy cover) to
a FIS controller to get an IFR pop-up, despite having filed a VFR plan with
almost exactly the same info.

"VFR on top" clearances, as Pete described are not used in Germany (in fact
they're not used outside the US). But you will find that practical IFR
clearances tend to include long direct legs, so it's unusual to be in a
situation where a VFR routing will save you a lot over an IFR one.

So where are you based?

Hope that helps

Julian Scarfe

"Andrew Gideon" wrote in message
online.com...
Is that likely to work? ATC may, after all, deny the "on top" clearance.

As Ditch says, ATC has the authority to deny the clearance, of course. But
since it makes their life easier, I don't know why they would. I have never
been denied a request for a "VFR on top" clearance. Granted, I fly VFR much
more often than IFR, but I just can't see why ATC would ever deny a "VFR on
top" clearance.

Pete