VFR on top

[Nick Kliewer]

In my understanding, the pilot is responsible for VFR separation from clouds
while operating "VFR on top." To what extent (and what would be the best way
to go about) to deviate heading to avoid clouds?

[John R. Copeland]

"Nick Kliewer" > wrote in message =
...
> In my understanding, the pilot is responsible for VFR separation from =
clouds
> while operating "VFR on top." To what extent (and what would be the =
best way
> to go about) to deviate heading to avoid clouds?

I wouldn't rely much upon deviation to avoid clouds during VFR-on-top.
I'd either climb higher to remain above the clouds, or else revert to =
ordinary IFR.

That said, however, if a solitary deviation of a few degrees were all =
I'd need,
I think I'd simply inform ATC of my need for some specific deviation,
in exactly the same way I'd handle a request for deviation
around an embedded thunderstorm showing on my radar.
For example, "Nxxxx requests deviation ten degrees left for weather."

[Steven P. McNicoll]

"Greg Farris" > wrote in message
...
>
> I can almost hear the center controller's hair being pulled out!
> You may be VFR, responsible for visual separation, but the IFR traffic
> near you is not. Suddenly you want ten degrees left! Maybe in wide-open
> places with little traffic - try asking something like that to Boston
> center.
>

Oh, but the IFR traffic near him IS just as responsible for visual
separation as he
is. It's the Center controller that has no separation responsibility in
this case.


§ 91.113 Right-of-way rules: Except water operations.

(b) General. When weather conditions permit, regardless of whether an
operation is conducted under instrument flight rules or visual flight rules,
vigilance shall be maintained by each person operating an aircraft so as to
see and avoid other aircraft. When a rule of this section gives another
aircraft the right-of-way, the pilot shall give way to that aircraft and may
not pass over, under, or ahead of it unless well clear.


>
> VFR on top is a wierd one.
> One gets the feeling controllers don't understand why pilots request this.
> Not sure I do either - unless, once again, you're out west somewhere,
> where it might give you some extra freedom.
>

It keeps you in the IFR system, whether that gives you "extra freedom" or
not is debatable. ATC's not gonna move you for traffic, but you may have to
move for clouds.

[Steven P. McNicoll]

"Peter" > wrote in message
...
>
> VFR on top is nevertheless a great favourite (favorite) of FAA IR
> examiners :)
>

Because few applicants have a thorough understanding of it.

[Dan Luke]

"Steven P. McNicoll" wrote:

>>
>> VFR on top is nevertheless a great favourite (favorite) of FAA IR
>> examiners :)
>>
>
> Because few applicants have a thorough understanding of it.

And few controllers. I've quit using it because it just isn't worth the
confusion.

--
Dan
C-172RG at BFM

[Greg Farris]

In article >,
says...
>
>
>
>"Steven P. McNicoll" wrote:
>
>>>
>>> VFR on top is nevertheless a great favourite (favorite) of FAA IR
>>> examiners :)
>>>
>>
>> Because few applicants have a thorough understanding of it.
>
>And few controllers. I've quit using it because it just isn't worth the
>confusion.
>
>--
>Dan
>C-172RG at BFM
>


The confusion is because the center controllers can't picture the 172 "on
top"!

Sorry - couldn't resist. :-)

[Dave Butler]

Greg Farris wrote:
> In article >,
> says...
>
>
>>I think I'd simply inform ATC of my need for some specific deviation,
>>in exactly the same way I'd handle a request for deviation
>>around an embedded thunderstorm showing on my radar.
>>For example, "Nxxxx requests deviation ten degrees left for weather."
>>
>
>
> I can almost hear the center controller's hair being pulled out!
> You may be VFR, responsible for visual separation, but the IFR traffic near
> you is not. Suddenly you want ten degrees left! Maybe in wide-open places with
> little traffic - try asking something like that to Boston center.

Really? I'm certainly surprised that would be a problem for Boston Center. I
don't fly in that airspace very often, but where I fly (NC and environs) those
kinds of deviations are pretty common. I don't know about VFR on top, but I mean
on an IFR plan.

[Dave Butler]

Dan Luke wrote:
> "Steven P. McNicoll" wrote:
>
>
>>>VFR on top is nevertheless a great favourite (favorite) of FAA IR
>>>examiners :)
>>>
>>
>>Because few applicants have a thorough understanding of it.
>
>
> And few controllers. I've quit using it because it just isn't worth the
> confusion.

Yeah, no kidding. Just this weekend I overheard someone on the radio request VFR
on top, and the controller responded with "IFR cancellation received"... Funny
thing is, that seemed to be just fine with the pilot, so I don't think either of
them knew what they were saying.

DGB

[[email protected]]

Peter > wrote:
: Here in the UK, a pilot with an IMC or Instrument Rating flying above
: an overcast layer can call himself "VFR". There just isn't any point
: that I can think of because he can legally call himself "IFR" and get
: a better service from ATC.

Ah, but the main advantage (AIUI) is that the IFR clearance "VFR on top" gives
you the flexibility of chosing your own routing while still staying in the system. In
congested airspace, it's often unlikely they'll give you a routing at IFR altitudes
due to conflicting traffic. With VFR on top they're more likely to let you through
without a big diversion.

: One problem might be if on an IFR flight plan (mandatory in Class A,
: or if crossing national boundaries) and then one has to be IFR as per
: the clearance.

: The U.S. rules confuse the hell out of me, especially if the question
: is on separation from cloud on a VFR on top clearance, at night, in
: class C... I suppose one has to memorise it only once per life and,
: out of the USA, one never needs to use any of it anyway.

No joke... What an unnecessary PITA. Its only real value seems to be filler
for exam questions.

-Cory

--

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

[Steven P. McNicoll]

> wrote in message
...
>
> Ah, but the main advantage (AIUI) is that the IFR clearance "VFR on top"
> gives
> you the flexibility of chosing your own routing while still staying in the
> system. In
> congested airspace, it's often unlikely they'll give you a routing at IFR
> altitudes
> due to conflicting traffic. With VFR on top they're more likely to let
> you through
> without a big diversion.
>

Clearance to maintain VFR-on-Top does not alter the assigned route. Given
that separation is no longer an issue it may be easier to obtain desired
routing, but it's still an IFR operation. If you're going to a destination
where IFR arrivals require some specified route you're still going to need
that route.

[Steven P. McNicoll]

"Peter" > wrote in message
...
>
> Why would this be?
>
> Forgive me for looking at this from the Euro POV, but it is true that
> if outside CAS one can fly anywhere one likes if VFR, whereas if IFR
> one is supposed to fly on ATS routes (published airways).
>
> However, there are countries (e.g. Greece) where *all* traffic (incl.
> VFR) is supposed to be on airway routes, and one can also get DCT
> clearances when IFR.
>
> Moreover, I can be flying VFR in CAS (say Class C) and be talking to
> some IFR (approach or departure) ATC unit, and they will be watching
> me (with a Mode C squawk) and in effect separating me and other
> traffic, occassionally giving me vectors. This is VFR, but it makes
> perfect sense.
>
> So I can't see why ATC would allow more routing leeway if VFR than if
> IFR. Does the minimum separation change?
>

Yes, aircraft operating VFR-on-top are treated as VFR aircraft for
separation purposes.

[[email protected]]

Steven P. McNicoll > wrote:
: Clearance to maintain VFR-on-Top does not alter the assigned route. Given
: that separation is no longer an issue it may be easier to obtain desired
: routing, but it's still an IFR operation. If you're going to a destination
: where IFR arrivals require some specified route you're still going to need
: that route.

That's what I meant, not necessarily what I said... :)

-Cory


--

************************************************** ***********************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
************************************************** ***********************

[Steven P. McNicoll]

"Peter" > wrote in message
...
>
> Separation between each other, or separation between IFR traffic and
> VFR traffic?
>

In all cases, as far as separation goes, aircraft operating VFR-on-top are
treated as VFR aircraft.

In Class D and E airspace VFR aircraft are provided no separation, nor are
aircraft operating VFR-on-top.

In Class C airspace VFR aircraft are separated from IFR aircraft, and
VFR-on-top aircraft are separated from IFR aircraft. Neither is separated
from other VFR or VFR-on-top aircraft.

In Class B airspace all aircraft are separated.

[KP]

"Peter" > wrote in message
...
>
> wrote
>
>> Ah, but the main advantage (AIUI) is that the IFR clearance "VFR on top"
>> gives
>>you the flexibility of chosing your own routing while still staying in the
>>system. In
>>congested airspace, it's often unlikely they'll give you a routing at IFR
>>altitudes
>>due to conflicting traffic. With VFR on top they're more likely to let
>>you through
>>without a big diversion.
>
> Why would this be?
>
> Forgive me for looking at this from the Euro POV, but it is true that
> if outside CAS one can fly anywhere one likes if VFR, whereas if IFR
> one is supposed to fly on ATS routes (published airways).
>
> However, there are countries (e.g. Greece) where *all* traffic (incl.
> VFR) is supposed to be on airway routes, and one can also get DCT
> clearances when IFR.
>
> Moreover, I can be flying VFR in CAS (say Class C) and be talking to
> some IFR (approach or departure) ATC unit, and they will be watching
> me (with a Mode C squawk) and in effect separating me and other
> traffic, occassionally giving me vectors. This is VFR, but it makes
> perfect sense.
>
> So I can't see why ATC would allow more routing leeway if VFR than if
> IFR. Does the minimum separation change?

Yes, you are looking at it from a euro-POV and I think that's the
disconnect.

In US Class D & E VFR are not separated from IFR.

In the US virtually all airspace is some class of controlled airspace; not
just airways and terminal areas. There is some Class G (just enough to
prompt some gotcha test questions or usenet replies) but for most
discussions it's N/A.

Within all that controlled airspace only one controller provides ATC Service
within any one particular chunk of airspace.

Since there is (virtually) no uncontrolled airspace and only one controller
is responsible for the controlled airspace (and thus should have his Big
Picture) there are no provisions (or really any need) for the ATSORA (RIS
and FIS but especially RAS) that you find in the UK.

When an aircraft in probably 90% of US airspace is VFR or in this discussion
VFR-On-Top, ATC is not responsible for separation.

The two main reasons for IFR re-routes or request denials are separation and
traffic flow/sequencing into the terminal area. Since VFR-On-Top
eliminates separation as a reason and sequencing only matters in the
terminal area the result is more flexibility when it comes to routing.

[Newps]

KP wrote:

> In the US virtually all airspace is some class of controlled airspace; not
> just airways and terminal areas. There is some Class G (just enough to
> prompt some gotcha test questions or usenet replies) but for most
> discussions it's N/A.

You must be east of the Mississippi. Look west. We have a lot of
uncontrolled airspace out here.

[Ron Rosenfeld]

On Tue, 11 Oct 2005 14:39:40 +0200, Greg Farris > wrote:

>I can almost hear the center controller's hair being pulled out!
>You may be VFR, responsible for visual separation, but the IFR traffic near
>you is not. Suddenly you want ten degrees left! Maybe in wide-open places with
>little traffic - try asking something like that to Boston center.

Much of my flying is in Boston Center airspace. I've never been denied a
deviation because of weather.


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

[KP]

"Newps" > wrote in message
...
>
>
> KP wrote:
>
>> In the US virtually all airspace is some class of controlled airspace;
>> not just airways and terminal areas. There is some Class G (just enough
>> to prompt some gotcha test questions or usenet replies) but for most
>> discussions it's N/A.
>
> You must be east of the Mississippi. Look west. We have a lot of
> uncontrolled airspace out here.

I am west.

Everything is relative and should be taken in context.

Compared to europe, and the UK in particular, where controlled airspace
consists of airways, fairly small, congested control zones, and that's about
it, the percentage of Class G in the Western US is insignificant.
Especially when compared to the amount of traffic (IFR and VFR) each
contain.

The civil controllers over there are pretty much hog-tied by a lack of
airspace to put IFR airplanes (which must remain in controlled airspace).
When I left in '92 timed approaches from holding patterns were SOP at
Heathrow. Just about everybody's on an airway; no off-airways directs and
not much in the way of re-routes available (they're all full).

If that's your context the idea that being VFR-On-Top could have any effect
on an aircraft's routing probably wouldn't register. There's no place else
to go regardless of whether you're at a hard altitude or OTP.

Outside of controlled airspace everybody's technically uncontrolled under
see-and-avoid. Whether they're in clear-and-severe or completely Popeye.
There are various types of air traffic services available from military
radar facilities. It's pretty much a free-for-all with multiple facilities
working aircraft in the same airspace. A coordination nightmare where you
must separate aircraft on your freq by 5NM or 5000 Mode C from any
unidentified or uncoordinated radar target.

If you haven't endured it it's a real head shaker :-/

[Dan Luke]

"Dave Butler" wrote:

>>>>VFR on top is nevertheless a great favourite (favorite) of FAA IR
>>>>examiners :)
>>>>
>>>
>>>Because few applicants have a thorough understanding of it.
>>
>>
>> And few controllers. I've quit using it because it just isn't worth
>> the confusion.
>
> Yeah, no kidding. Just this weekend I overheard someone on the radio
> request VFR on top, and the controller responded with "IFR
> cancellation received"...

I've never had that happen, though one controller did ask if that was
what I wanted. The trouble usually came on handoffs, where the next
controller would want to know if I was still on an IFR flightplan, etc.

--
Dan
C172RG at BFM

[Chris]

"KP" <nospam@please> wrote in message
. ..
> "Newps" > wrote in message
> ...
>>
>>
>> KP wrote:
>>
>>> In the US virtually all airspace is some class of controlled airspace;
>>> not just airways and terminal areas. There is some Class G (just enough
>>> to prompt some gotcha test questions or usenet replies) but for most
>>> discussions it's N/A.
>>
>> You must be east of the Mississippi. Look west. We have a lot of
>> uncontrolled airspace out here.
>
> I am west.
>
> Everything is relative and should be taken in context.
>
> Compared to europe, and the UK in particular, where controlled airspace
> consists of airways, fairly small, congested control zones, and that's
> about it, the percentage of Class G in the Western US is insignificant.
> Especially when compared to the amount of traffic (IFR and VFR) each
> contain.
>
> The civil controllers over there are pretty much hog-tied by a lack of
> airspace to put IFR airplanes (which must remain in controlled airspace).
> When I left in '92 timed approaches from holding patterns were SOP at
> Heathrow. Just about everybody's on an airway; no off-airways directs and
> not much in the way of re-routes available (they're all full).
>
> If that's your context the idea that being VFR-On-Top could have any
> effect on an aircraft's routing probably wouldn't register. There's no
> place else to go regardless of whether you're at a hard altitude or OTP.
>
> Outside of controlled airspace everybody's technically uncontrolled under
> see-and-avoid. Whether they're in clear-and-severe or completely Popeye.
> There are various types of air traffic services available from military
> radar facilities. It's pretty much a free-for-all with multiple
> facilities working aircraft in the same airspace. A coordination
> nightmare where you must separate aircraft on your freq by 5NM or 5000
> Mode C from any unidentified or uncoordinated radar target.
>
> If you haven't endured it it's a real head shaker :-/

I would agree its a real belter flying IFR in uncontrolled airspace taking
Radar Advisory Service when a nearby aircraft might be getting a service
from someone else. It become a real relief when you can move into Controlled
airspace usually Class A and have the benefit of London Control looking
after you. But getting into CAS is not easy either even with an IFR flight
plan.

[Chris]

"Peter" > wrote in message
...
>
> "Chris" > wrote
>
>>I would agree its a real belter flying IFR in uncontrolled airspace taking
>>Radar Advisory Service when a nearby aircraft might be getting a service
>>from someone else. It become a real relief when you can move into
>>Controlled
>>airspace usually Class A and have the benefit of London Control looking
>>after you.
>
> Statistically, the risk of a mid-air in IMC is closer to zero then
> most risks we routinely accept in life.
>
>>But getting into CAS is not easy either even with an IFR flight
>>plan.
>
> Could you please expand on this? If you file an IFR flight plan (a
> proper ICAO one) which passes through CAS then you will get ATS radar
> service all the way. The flight plan, if on a route acceptable to
> CFMU, must be accepted. Not exactly as filed but the general route
> won't be refused.

I recently went from White Waltham to Jersey.

Even though I had used DCT in CAS to get to Southampton, all the Radar
controllers instructed me to remain outside controlled airspace. This meant
scrambling along in marginal VFR until I got to north of the Solent area and
climbed to 4000 in Class G in IMC and waited for clearance into the Solent
Area (Class D).

I was kept holding outside outside the Southampton Zone for 20 minutes
before being allowed to enter CAS. In fact when I was passed onto Solent
from Farnborough, I was greeted with the statement " remain outside
controlled airspace until I get back to you which might not be today, we are
busy."

Eventually, I was cleared in the CTA and vectored around Southampton to the
Isle of Wight when I was given my airways clearance (Class A) to Jersey and
transferred to London Control where normality prevailed all the way to
Jersey with a STAR and the ILS to 27.
(the stupid thing is that flying the N reg plane my legal minimums on the
ILS approach are way less than if I was flying a G reg using my IMC rating
privileges.

Anyway, what other flight plan is there to file unless its a proper ICAO
one?

[Tim Auckland]

So, as a Bolton lad now living, working, and flying (for fun) in
Colorado, I'm intrigued to know if things are noticably less congested
north of, say, a Livepool - Hull line; or does flight shrink the
country so much that the traditional north/south divide doesn't exist
in the air?

(I'm spoilt rotten out here; VMC weather 300 days a year, petrol is
still less than $3.00 for a US gallon, about 4 million people living
in the state of Colorado which is bigger than Northern Ireland,
Scotland, Wales and England combined, and good showers!)

Tim.

On Thu, 13 Oct 2005 18:36:00 +0100, "Chris" >
wrote:

>
>"Peter" > wrote in message
...
>>
>> "Chris" > wrote
>>
>>>I would agree its a real belter flying IFR in uncontrolled airspace taking
>>>Radar Advisory Service when a nearby aircraft might be getting a service
>>>from someone else. It become a real relief when you can move into
>>>Controlled
>>>airspace usually Class A and have the benefit of London Control looking
>>>after you.
>>
>> Statistically, the risk of a mid-air in IMC is closer to zero then
>> most risks we routinely accept in life.
>>
>>>But getting into CAS is not easy either even with an IFR flight
>>>plan.
>>
>> Could you please expand on this? If you file an IFR flight plan (a
>> proper ICAO one) which passes through CAS then you will get ATS radar
>> service all the way. The flight plan, if on a route acceptable to
>> CFMU, must be accepted. Not exactly as filed but the general route
>> won't be refused.
>
>I recently went from White Waltham to Jersey.
>
>Even though I had used DCT in CAS to get to Southampton, all the Radar
>controllers instructed me to remain outside controlled airspace. This meant
>scrambling along in marginal VFR until I got to north of the Solent area and
>climbed to 4000 in Class G in IMC and waited for clearance into the Solent
>Area (Class D).
>
>I was kept holding outside outside the Southampton Zone for 20 minutes
>before being allowed to enter CAS. In fact when I was passed onto Solent
>from Farnborough, I was greeted with the statement " remain outside
>controlled airspace until I get back to you which might not be today, we are
>busy."
>
>Eventually, I was cleared in the CTA and vectored around Southampton to the
>Isle of Wight when I was given my airways clearance (Class A) to Jersey and
>transferred to London Control where normality prevailed all the way to
>Jersey with a STAR and the ILS to 27.
>(the stupid thing is that flying the N reg plane my legal minimums on the
>ILS approach are way less than if I was flying a G reg using my IMC rating
>privileges.
>
>Anyway, what other flight plan is there to file unless its a proper ICAO
>one?
>
>

[Chris]

"Peter" > wrote in message
...
>
> "Chris" > wrote
>
>>Even though I had used DCT in CAS to get to Southampton, all the Radar
>>controllers instructed me to remain outside controlled airspace. This
>>meant
>>scrambling along in marginal VFR until I got to north of the Solent area
>>and
>>climbed to 4000 in Class G in IMC and waited for clearance into the Solent
>>Area (Class D).
>>
>>I was kept holding outside outside the Southampton Zone for 20 minutes
>>before being allowed to enter CAS. In fact when I was passed onto Solent
>>from Farnborough, I was greeted with the statement " remain outside
>>controlled airspace until I get back to you which might not be today, we
>>are
>>busy."
>
> I *think* the above happened because in the UK the ATS routes are all
> in Class A, and you were below Class A. You should have got an IFR
> departure right away, into the Class A TMA whose base is at 2500ft
> there. What was your initial FP altitude/level? If it was under 2500ft
> that would explain it. One has to file an FP whose initial requested
> level is straight into Class A.

I did, my FL65 out of WW which is straight into CAS but I was kept out of
it, maybe because its in the climb out from Heathrow. So, my flight plan
went for a burton from the off.

> Maybe you mean something specific to Jersey, but that is in a Class A
> CTR and you cannot go there IFR without the full IR anyway.

Exactly that, and the visibility.