"VFR on top" clearance. . .

[SilverFlyer]

. . . and cloud minimums. Flying in Socal I often obtain a VFR on top clearance so that I can fly up through the marine layer and carry on VFR. My question is, before cancelling IFR don't I have to be 1,000 feet above the cloud layer? I'm usually asked to report the tops, but once I do I'm asked if I would like to cancel IFR. If I do isn't this breaking regs?

 

[81Horse]

. . . I'm usually asked to report the tops, but once I do I'm asked if I would like to cancel IFR. If I do isn't this breaking regs?

Probably. So don't do it.

It's not like you have to be spring-loaded to report the tops or cancel. Wait till you reach or climb through a legal altitude, then report what the tops were and cancel IFR. One transmission; simple.

 

[mar]

Two different things

There are two different operations:

1) VFR-on-top

2) VFR over the top.

The first one is an IFR clearance where you must maintain VFR cloud clearances.

The second one is a VFR operation where you must maintain VFR cloud clearances.

You can report the tops when you break out but hang on to your IFR clearance until you're in VFR conditions by advising ATC you're unable VFR at this time and would like to remain IFR.

 

[AC560]

My understanding has always been that if you are filed VFR on top you are still on a IFR plan just operating at VFR altitudes and rules, thus I never understood the point to it was.

Wouldn't it just be simpler to file, climb up, and then cancel when VFR as opposed to being filed VFR on top (why cancel in the first place considering you get direct almost anywhere with a GPS now anyways)?

 

[mar]

Flexibility

My understanding has always been that if you are filed VFR on top you are still on a IFR plan just operating at VFR altitudes and rules, thus I never understood the point to it was.

Wouldn't it just be simpler to file, climb up, and then cancel when VFR as opposed to being filed VFR on top (why cancel in the first place considering you get direct almost anywhere with a GPS now anyways)?

Not every corner of the nation is glowing with radar coverage and saturated with VOR coverage.

Sometimes you want the flexibility of flying VFR with the ability to remain IFR. It's the best of both worlds.

 

[SilverFlyer]

It's not like you have to be spring-loaded to report the tops or cancel. Wait till you reach or climb through a legal altitude, then report what the tops were and cancel IFR. One transmission; simple.

Now why didn't I think of that??? My take has been to report as soon as I break through, but waiting just makes sense. Thanks all for the replies.

 

[MauleSkinner]

Now why didn't I think of that??? My take has been to report as soon as I break through, but waiting just makes sense. Thanks all for the replies.

Remember, controllers are like mechanics (no offense intended to either, btw)...The requirements of Part 91 aren't necessarily what they're thinking about. It's your responsibility as PIC to maintain legality, which obviously you're thinking about by posting this question

Fly safe!

David

 

[AC560]

Not every corner of the nation is glowing with radar coverage and saturated with VOR coverage.

Sometimes you want the flexibility of flying VFR with the ability to remain IFR. It's the best of both worlds.

If you are VFR on top how are you going to navigate with no VOR? Plus I thought once you accept a VFR on top clearance you could no longer fly in IMC conditions so you really aren't IFR persay. I just really don't understand the benefit, seems it would be better to either stay IFR or cancel completely and refile if needed to get down.

 

[groundpointsix]

If you are VFR on top how are you going to navigate with no VOR? Plus I thought once you accept a VFR on top clearance you could no longer fly in IMC conditions so you really aren't IFR persay. I just really don't understand the benefit, seems it would be better to either stay IFR or cancel completely and refile if needed to get down.

How am I going to navigate without a VOR? Well, there's always GPS, NDBs, LORAN, ded reckoning, pilotage (ok, a stretch in this situation), and celestial navigation. I might have forgotten something. The point is there are pleanty of ways to do it.

One reason I might go VFR on top is that there is no airway between A and B that gives me a relatively straight course. Let's assume I'm in an area with reduced radar coverage. ATC is most likely not going to give me a random route in this situation. By going VFR on top, I've relieved them of the responsibility to separate me and I can now go direct by one of the methods I listed above.

Why don't I cancel and just refile? Sure, I could do that, but now I have to call flight service and file a second flight plan or try to work it out with the center controller, which he may or may not have time for. By going VFR on top all I have to tell him is I'm ready to go IFR again and I'm back in the system with one radio call instead of having a conversation or giving a 30 second radio call with all my flight plan information.

 

[A Squared]

My understanding has always been that if you are filed VFR on top you are still on a IFR plan just operating at VFR altitudes and rules, thus I never understood the point to it was.

Wouldn't it just be simpler to file, climb up, and then cancel when VFR as opposed to being filed VFR on top (why cancel in the first place considering you get direct almost anywhere with a GPS now anyways)?

As mar said, it's a matter of flexibility. Most of the time under Part 121, you are required to be IFR, so cancelling is not an option, usually. One example. you are descending to a non-radar destination on a VFR day. Another IFR plane has already departed, headed toward you. ATC will assign altitude restrictions to both plans until passage is assured, usually by DME reports. Now, if you are cleared "vfr on top", you may descend at your discretion, and you are not given altitude restrictions which conflict with your plan for descending into the airport.

Another advantage is that under Part 121 (but interestingly, not under part 91 or 135) you may descend below the MEA on a "VFR on Top" clearence. AN example of where this is useful is coming into Anchorage eastbound on V319, the MEA is 12,000 until 50 west of ANC, even though the mountains are *well* behind you. (WEstbound you may cross 50 west of ANC at 8100 headed *toward* the mountains, but easbound away from the mountains, they keep you at 12K, go figure) Anyway, it's very difficult to lose 12,000 ft in 50 nm in hte DC-6 and still observe all your limitations and proper engine management, especially with a tailwind. However, if you're VFR on Top, you can start your descent from 12K much earlier, and make it easier on the engines.

 

[mar]

Let me think...

If you are VFR on top how are you going to navigate with no VOR? Plus I thought once you accept a VFR on top clearance you could no longer fly in IMC conditions so you really aren't IFR persay. I just really don't understand the benefit, seems it would be better to either stay IFR or cancel completely and refile if needed to get down.

...ok, ok, I can see you're gonna make me work for this one. I was just hoping you'd take my word for it, but let me think of an example...

Let's say you're in a training situation and you want to do some airwork. The airport is IFR, so you file a flight plan from airport XYZ to ABC VOR, when you contact departure you explain you're in VMC and would like to manuever in a block of airspace and then return for the ILS at airport XYZ.

Since the primary purpose of ATC is to separate IFR aircraft from other IFR aircraft, you get *some* separation service (probably not in the "block" but at least that airspace is set aside and he knows about you) and then when you're ready to return all it takes is a call to report the latest ATIS and a request for the ILS. You already have a squawk, he already has a flight data strip, radar contact is already established. All you need is a vector.

In an enroute scenario, your airway might actually be defined by an NDB. Don't laugh. They're out there.

Or maybe there's icing at your assigned altitude and you want to climb out of it but you don't want to cancel your flight plan because you know you'll need it later on....

There are just dozens of scenarios that you can run into. It's worth knowing about it.

Good luck.

 

[A Squared]

Plus I thought once you accept a VFR on top clearance you could no longer fly in IMC conditions so you really aren't IFR persay.

If you're on a VFR on top clearence, you'd better believe that you are IFR, You are flying by Instrument Flight Rules (that's what IFR means, IFR isn't a weather condition) The only difference is, you can pick your own altitude, you fly at VFR altitudes and you must comply with VFR cloud clearences, other than that, *all* of the instrument flight rules are in effect and you are obligated to comply with them.

 

[Amish RakeFight]

AS I understand it, even though you're VFR-On-Top complying with IFR and VFR rules, ATC no longer provides the same traffic separation.

 

[A Squared]

AS I understand it, even though you're VFR-On-Top complying with IFR and VFR rules, ATC no longer provides the same traffic separation.

Correct. For purposes of traffic seperation see and avoid applies

 

[81Horse]

SilverFlyer, it seemed like the scenario you were asking about was something like: "Cleared to ABC, report reaching VFR conditions on top ... if not on top at/by xx00, maintain xx00 and advise ..."

In other words, a clearance designed to be cancelled as soon as you reach VFR conditions. So of course, the controllers are just waiting on you to break out and cancel.

And the others here are quite correct -- VFR-on-top is an IFR clearance, with instructions to maintain VFR conditions in lieu of a hard altitude.

 

[727gm]

You may also want to stay out of the clouds UNDER an overcast that the normal enroute clearance would put you in, if you are flying an aircraft without anti/de-icing equipment. Nothing about VFR-on-top says you have to be ABOVE the clouds. VFR-on top allows you to stay IFR, without trying to work out a new clearance while enroute.

 

[C-141/C-5]

WHY DON"T YOU JUST FILE A RADIAL DME OF A VORTAC?? You stay on an IFR flight plan and make your own straight line point. If you have an IFR rated GPS then i would just file direct.

VFR on top makes no sense to me. You don't have another set of eyes helping you clear and isn't VFR flying using pilotage and dead reckoning??? Kind of hard to do when you can't see the ground.

 

[81Horse]

VFR on top makes no sense to me.

VFR-on-top takes the place of a hard altitude -- what's the mystery? You retain your IFR clearance and routing, while maintaining a VFR altitude (and VMC). It can be a handy way to bypass or work around other IFR traffic -- which is no doubt the reason it came into being to start with.

 

[727gm]

WHY DON"T YOU JUST FILE A RADIAL DME OF A VORTAC??

Many light aircraft do not have DME installed(or GPS for that matter).

VFR-on-Top is an IFR clearance. No need to see the ground, and no need for dead reckoning, radio navigation is normally used.

 

[mar]

So don't use it.

VFR on top makes no sense to me.

I thought Asquared gave a good example of when it comes in handy.

Nobody is forcing you to request this service.

Just because you don't have a use for it doesn't make it senseless.