Why VFR on top?

[woodchucker]

Just curious here, why go this route? Looking at an FAA source, this would be an IFR flight requesting VFR on top. Why would a pilot bother with this? Why not just stay IFR?

 

[SoonerAviator]

No IR here, but possibly to eliminate being told what route/altitude to fly? I'm sure it's not usually a problem but if you could save time/fuel by going direct, then why not go VFR on top? It's not like you wouldn't be able to pick up IFR later on if needed.

 

[Witmo]

No IR here, but possibly to eliminate being told what route/altitude to fly? I'm sure it's not usually a problem but if you could save time/fuel by going direct, then why not go VFR on top? It's not like you wouldn't be able to pick up IFR later on if needed.

You're still going to fly the route you are cleared for, but it's less tiring to fly looking out of the cockpit than scanning the guages. You're still on an IFR flight plan so no worries getting through the cloud deck.

 

[roncachamp]

No IR here, but possibly to eliminate being told what route/altitude to fly? I'm sure it's not usually a problem but if you could save time/fuel by going direct, then why not go VFR on top? It's not like you wouldn't be able to pick up IFR later on if needed.

A VFR-on-Top clearance does not affect your route. You can operate in VMC at any appropriate VFR altitude not below the minimum IFR altitude or within Class A airspace but you're still tied to your route. VFR-on-Top may simplify route requests but a change in route is a separate issue.

 

[roncachamp]

Just curious here, why go this route? Looking at an FAA source, this would be an IFR flight requesting VFR on top. Why would a pilot bother with this? Why not just stay IFR?

The only real advantage I see is NAVAID service volume limitations do not apply to routes when the aircraft is cleared VFR-on-Top.

 

[RyanB]

If it's a good shot at VFR on top, it would allow you to climb to a higher altitude for better winds than you may not have had before.

 

[dukeblue219]

You're still going to fly the route you are cleared for, but it's less tiring to fly looking out of the cockpit than scanning the guages. You're still on an IFR flight plan so no worries getting through the cloud deck.

Not sure I see the difference -- in either case you're in good VMC and can keep your eyes outside more. You still need to maintain altitude and course and still need to keep up with the radio work.

I agree, I've never understood why I would specifically ask for VFR on top.

 

[roncachamp]

You're still going to fly the route you are cleared for, but it's less tiring to fly looking out of the cockpit than scanning the guages. You're still on an IFR flight plan so no worries getting through the cloud deck.

I fail to see how operating VFR-on-Top keeps you off the gauges. VFR-on-Top requires an appropriate VFR altitude and compliance with VFR cloud clearance. If you comply with those requirements there should be an IFR altitude 500' below you that is at least 500' above the clouds.

 

[peerlesscowboy]

Just curious here, why go this route? Looking at an FAA source, this would be an IFR flight requesting VFR on top. Why would a pilot bother with this? Why not just stay IFR?

VFR on Top relieves ATC of the nessesity of providing IFR separation which can be to your operational advantage in some circumstances.

 

[acrophile]

NAVAID service volume limitations do not apply to routes when the aircraft is cleared VFR-on-Top.

Thanks, I wasn't aware of that. Is that something I missed in the FARs or AIM, or is it only noted in publications for controllers?

 

[steingar]

I fail to see how operating VFR-on-Top keeps you off the gauges. VFR-on-Top requires an appropriate VFR altitude and compliance with VFR cloud clearance. If you comply with those requirements there should be an IFR altitude 500' below you that is at least 500' above the clouds.

If you're at 8k feet and the cloud deck is at 3K feet it really isn't a big worry.

 

[roncachamp]

Thanks, I wasn't aware of that. Is that something I missed in the FARs or AIM, or is it only noted in publications for controllers?

I don't think you'll find it mentioned in the FARs or AIM, Order JO 7110.65 Air Traffic Control has this:

4−1−4. VFR-ON-TOP

Use a route not meeting service volume limitations only if an aircraft requests to operate “VFR-on-top” on this route.

 

[bobmrg]

This comes up so often that there ought to be a sticky about it. OTP is a valuable tool, and there are many on this forum who have used it to operational advantage. If you don't like it (or don't understand it), remove it from your aviation lexicon.

Bob Gardner

 

[poadeleted20]

The only real advantage I see is NAVAID service volume limitations do not apply to routes when the aircraft is cleared VFR-on-Top.

While FAA Order 7110.65 allows controllers to do that:

4−1−4. VFR-ON-TOP

Use a route not meeting service volume limitations​

only if an aircraft requests to operate “VFR-on-top”​

on this route.

...I foresee a problem for the pilot who makes that request if s/he gets off course while trying to fly beyond the service volume limitations of the navaid being used. Remember -- you, the pilot, are still obligated to stay on the assigned route without the controller's help when flying "own nav" under IFR, both on a regular "hard" altitude clearance and on a VFR-on-top clearance. If it turns out there's a problem with that navaid signal beyond the SSV and it results in you going off course and a problem results, it will be you, the pilot, who has to explain your failure to stay where you were supposed to be even if the controller was operating within the constraints of 7110.65.

 

[Dr. O]

OK, I'll bite.
What is, because I can?





What do I win?

 

[skidoo]

Is it a better way to dodge clouds while temps are below freezing? Say you are crossing the top of an icing overcast, but there are some scattered clouds at your altitude that you want to avoid due to icing potential. Would ATC be more likely to provide requested course deviations with a VFR on top clearance or not? I assume you would still need to request each deviation of course around such clouds?

 

[skidoo]

I don't think you'll find it mentioned in the FARs or AIM, Order JO 7110.65 Air Traffic Control has this:

4−1−4. VFR-ON-TOP

Use a route not meeting service volume limitations only if an aircraft requests to operate “VFR-on-top” on this route.

Hate to ask, but what is a "service volume limitation"?

 

[nosehair]

Mainly, I see it as an opportunity to stay at an altitude that will allow you and/ or your passengers to look outside. Gets terribly boring looking into white cotton.
Easier to avoid the 4-5000 tops of building Cumulus, too.
But your still IFR. If you can't stay a good vfr, then you just have to get a hard altitude.
Your route clearance is still going.

 

[Turningfinal]

Mainly, I see it as an opportunity to stay at an altitude that will allow you and/ or your passengers to look outside. Gets terribly boring looking into white cotton.
Easier to avoid the 4-5000 tops of building Cumulus, too.
But your still IFR. If you can't stay a good vfr, then you just have to get a hard altitude.
Your route clearance is still going.

As roncachamp pointed out, if you're properly complying with cloud clearance requirements (1000' above) while VFR-on-top, there should be an IFR altitude 500' below you that remains clear of clouds also.

 

[roncachamp]

Is it a better way to dodge clouds while temps are below freezing? Say you are crossing the top of an icing overcast, but there are some scattered clouds at your altitude that you want to avoid due to icing potential. Would ATC be more likely to provide requested course deviations with a VFR on top clearance or not? I assume you would still need to request each deviation of course around such clouds?

As ATC has no responsibility for separation while you're operating VFR-on-Top there's little reason to deny the request to deviate. Bear in mind that you must comply with VFR cloud clearance while you're deviating.

 

[roncachamp]

Hate to ask, but what is a "service volume limitation"?

The maximum usable distances of the various types and classes of NAVAIDs for the altitude.

 

[cowman]

I'm not IR either but I'm starting in on studying some of it.

As I understand it you can't fly IFR through an active MOA.... would going VFR on top be a way of getting through that airspace without a major detour?

 

[poadeleted20]

Hate to ask, but what is a "service volume limitation"?

All navaids have a "standard service volume" within which accurate navigation signals are guaranteed unless otherwise published in the A/FD or by NOTAM. You can find these in Section 1 of the AIM for the various types and classes of navaids. For example, here's the SSV for a Terminal class VOR:

Outside that volume, there are no guarantees of reception/accuracy unless they've been specifically flight-checked by the FAA as part of a published route. For example V44 runs 94 miles from MRB to MGW even though those two VOR's have only a 40 mile radius each at V-airway altitudes. However, the FAA has flight-checked the length of that airway all the way and determined that it's possible to fly it safely at the 5000 MSL MEA. They did put a change-over point (COP) 41 miles out from MRB and 53 miles out from MGW which is where you lose the MRB signal at MEA but you can pick up the MGW signal that far out at that altitude.

Controllers are normally not permitted to let you fly outside the SSV's (other than on published routes like V44) under IFR when using the navaids for navigation (as opposed to radar vectors or approved area navigation systems). The section cited allows them to clear you on direct navaid-to-navaid routes beyond the SSV (or other limitations from the A/FD or NOTAMs) under VFR-on-top if you request it.

My point in response to Steven's noting of that point is that you'd better be darn careful about making that request, because if you drift off course due to signal problems outside the SSV (or beyond those published limits), it's going to be entirely on your head, not the controller's, since you were entirely responsible for your own navigation. And while Steven made a point about separation from other aircraft, that's not the only thing from which you must remain separated, e.g., special use airspace or terrain. Now, one would expect that terrain would not be an issue if you remained in VMC in daylight, but you might not see terrain out there at night, and other than the flashing light system in the DC area, SUA's don't have big yellow "DO NOT CROSS" police tape up in the sky.

 

[Clark1961]

I'm not IR either but I'm starting in on studying some of it.

As I understand it you can't fly IFR through an active MOA.... would going VFR on top be a way of getting through that airspace without a major detour?

You can fly IFR through an active MOA as long as it is coordinated. Yes, VFR would be one way to go through it but do you really wanna be there? A T-38 at 400 knots is just a little difficult to see...

 

[nosehair]

As roncachamp pointed out, if you're properly complying with cloud clearance requirements (1000' above) while VFR-on-top, there should be an IFR altitude 500' below you that remains clear of clouds also.

Are you?,,,is that a "justification" to you for staying at a hard IFR altitude?
First, it may not be available, but mainly, when those building Cumulus start eating into your smooth ride, vfr-on-top, you simply climb to a better altitude. on your own.

 

[poadeleted20]

I'm not IR either but I'm starting in on studying some of it.

As I understand it you can't fly IFR through an active MOA.... would going VFR on top be a way of getting through that airspace without a major detour?

Basically, no. Per the controller's manual section on VFR-on-top and special use airspace:

9-3-3. VFR-ON-TOP

If the aircraft’s route, track, or altitude may cause it​

to enter an active Prohibited/Restricted/Warning​

Area, MOA, or ATCAA:​

a. Inform the pilot to conduct flight “VFR−on−top” at least 500 feet above the upper limit or below the lower limit of the airspace (subject to para 7−3−1, VFR−on−top); or​

PHRASEOLOGY ​

−​

MAINTAIN VFR-ON-TOP AT LEAST 500 FEET​

ABOVE/BELOW (upper/lower limit of airspace) ACROSS​

(name or number of airspace) BETWEEN (fix) AND (fix);​

and if the airspace is an ATCAA,​

(name of ATCAA) IS ATC ASSIGNED AIRSPACE.

REFERENCE​

−​

FAAO JO 7110.65, Para 7-1-1,​

​

​

​

Class A Airspace Restrictions.​

b.​

Clear the aircraft via a routing which provides approved separation from the airspace.​

c.​

Exception: Some Prohibited/Restricted Areas are established for security reasons or to contain hazardous activities not involving aircraft operations. The addition of 500 (or 1,000) feet to the upper/lower limit of these Prohibited/Restricted Areas is not required if the areas have been identified by facility management.​

REFERENCE -​

FAAO JO 7210.3, Para 2−1−17, Prohibited/Restricted

 

[poadeleted20]

You can fly IFR through an active MOA as long as it is coordinated.

Takes more than just "coordination". It requires an LOA/LOP for such transits between the FAA and the using agency, and direct coordination with the using agency for that specific transit. See section 9-3-4 in FAA Order 7110.65. You'd need to ask a controller how often that's possible.

 

[skidoo]

All navaids have a "standard service volume" within which accurate navigation signals are guaranteed unless otherwise published in the A/FD or by NOTAM. You can find these in Section 1 of the AIM for the various types and classes of navaids. For example, here's the SSV for a Terminal class VOR:

Outside that volume, there are no guarantees of reception/accuracy unless they've been specifically flight-checked by the FAA as part of a published route. For example V44 runs 94 miles from MRB to MGW even though those two VOR's have only a 40 mile radius each at V-airway altitudes. However, the FAA has flight-checked the length of that airway all the way and determined that it's possible to fly it safely at the 5000 MSL MEA. They did put a change-over point (COP) 41 miles out from MRB and 53 miles out from MGW which is where you lose the MRB signal at MEA but you can pick up the MGW signal that far out at that altitude.

Controllers are normally not permitted to let you fly outside the SSV's (other than on published routes like V44) under IFR when using the navaids for navigation (as opposed to radar vectors or approved area navigation systems). The section cited allows them to clear you on direct navaid-to-navaid routes beyond the SSV (or other limitations from the A/FD or NOTAMs) under VFR-on-top if you request it.

My point in response to Steven's noting of that point is that you'd better be darn careful about making that request, because if you drift off course due to signal problems outside the SSV (or beyond those published limits), it's going to be entirely on your head, not the controller's, since you were entirely responsible for your own navigation. And while Steven made a point about separation from other aircraft, that's not the only thing from which you must remain separated, e.g., special use airspace or terrain. Now, one would expect that if you remained in VMC in daylight, you might not see terrain out there at night, and other than the flashing light system in the DC area, SUA's don't have big yellow "DO NOT CROSS" police tape up in the sky.

Thanks!

 

[bobmrg]

Hate to ask, but what is a "service volume limitation"?

Hate to point this out, but there were SSV questions in the knowledge test bank when you took your private written...you just didn't get one assigned to you.

Bob Gardner

 

[roncachamp]

As I understand it you can't fly IFR through an active MOA.... would going VFR on top be a way of getting through that airspace without a major detour?

You can fly IFR through an active MOA if procedures have been established with the using agency to route nonparticipating IFR aircraft through it. That includes VFR-on-Top.

 

[Clark1961]

Takes more than just "coordination". It requires an LOA/LOP for such transits between the FAA and the using agency, and direct coordination with the using agency for that specific transit. See section 9-3-4 in FAA Order 7110.65. You'd need to ask a controller how often that's possible.

That fits my definition of coordination. Dunno what yer so up tight about...

 

[brcase]

I haven't done it for a while but I have requested VFR on top with the local Approach Control (Class C) when doing initial instrument training we would get a clearance to climb up though the 1000' thick inversion layer. Once on top would request VFR on top for maneuvering for doing things like Pattern A, Pattern B, Unusual Attitudes, Steep Turns, Etc. It also allowed ATC to keep us closer to he airport after a missed (simulated) approach while vectoring us back for another approach. Apparently since we are VFR, they don't need as much separation from other aircraft as they do when both aircraft are IFR.

Brian

 

[skidoo]

Hate to point this out, but there were SSV questions in the knowledge test bank when you took your private written...you just didn't get one assigned to you.

Bob Gardner

Probably why I hated to ask... It has been more than 40 years since I took such a written. Some things one just doesn't recall...

 

[jordane93]

Turbulence, better winds aloft, etc.

 

[SkyHog]

I have always wondered this too. What benefit aside from SSV do you get by going VFR on Top? Everything pointed out so far is available to IFR anyway and I doubt a 500ft different is going to matter too much for weather (that is, if 4000 is IMC and 4500 is VMC, I doubt youre going to find considerably better winds than you would have at 5000 or 6000ft.

 

[PaulMillner]

Takes more than just "coordination". It requires an LOA/LOP for such transits between the FAA and the using agency, and direct coordination with the using agency for that specific transit. See section 9-3-4 in FAA Order 7110.65. You'd need to ask a controller how often that's possible.

I was pleasantly surprised to get one by requesting it just last week!


Controller said, "Let me check." Came back a minute later, "Cleared direct..."


Paul

 

[winrose46]

When I have used it the destination is VFR and the routing provided on my IFR flight plan is way out of my way so I have just requested VFR and flown my own routing.

 

[roncachamp]

When I have used it the destination is VFR and the routing provided on my IFR flight plan is way out of my way so I have just requested VFR and flown my own routing.

Requested VFR? Do you mean requested VFR-on-Top or did you simply cancel IFR? If VFR-on-Top, did you obtain a revised route from ATC?

 

[coma24]

It allows you to select whichever VFR cruising altitude is best for you, regardless of traffic, as long as it's above the minimum instrument altitude.

 

[bobmrg]

When I have used it the destination is VFR and the routing provided on my IFR flight plan is way out of my way so I have just requested VFR and flown my own routing.

VFR is to VFR-on-top as watermelons are to Toyotas.

Bob Gardner