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IFR rules, VFR Tools: when the weather's good, IFR pilots have a lot more flexibility than when it's too foggy to drive to the airport. Know what they are and when you can use them.

If you've had your Instrument rating for a few years, filing IFR has probably become second nature for you. Before launching on a cross-country, you naturally pick up the phone to file, even when the weather is CAVU. The idea of not filing an IFR flight plan doesn't really occur to you. Until, that is, you're at mid-point on a published departure procedure, wondering why you're doing all this knob-twisting--and you're probably not even headed toward your destination. Wouldn't it be nice to have the privileges of the Instrument rating and the freedoms of flying VFR? Well, you often can.

When it comes to clearances, you can cut some deals with ATC most of the time. Of course, as with anything involving the FAA, there are a few strings attached. However, your concerns should not be over any shadows of duplicity, but instead, heeding a few words of caution.

PERKS AND QUIRKS

If you're an Instrument-rated pilot, you already know that being able to file IFR adds a great deal of utility to your airplane. You are no longer restrained when the weather is below basic VFR for the airspace you happen to be in. Also, if you ever need help, it's already there. You're guaranteed automatic separation--though only from other IFR aircraft--you get spoon-fed approach vectors and you're led by the hand through today's modernday maze of airspace. Those are the perks.

Some quirks exist, also. Sometimes, you have to sit and wait for a clearance--even idling the engine in the penalty box can quickly get expensive. Circuitous routings, or getting stuck at an altitude with headwinds, turbulence, icing or convective weather also are some of the prices we pay. Still, there are many more good reasons than not to fly in the IFR system. For now, we'll assume visual meteorological conditions (VMC) prevail and that the controller you're talking to isn't distractedly busy. Why VMC? Unless you're a frequent foul-weather flyer by choice, the fact is that most of the time, that's really what we fly in.

Regarding one of these quirks, I'm sure that almost every single Instrument-rated reader has at least once gotten an assigned initial heading that pointed them almost directly away from their destination, rather than toward it. Aside from filing for a direct routing (hah!), you could ask for a different altitude or a heading change (though this kind of request is usually expected when ice, convective weather or some other problem is involved).

DEPARTURE OPTIONS

The first option to consider is when the weather along your route is actually pretty good, but there's a low cloud layer over your departure airport. You don't have to go the whole way IFR, if you don't want to. In this case, the type of IFR clearance you might want to consider is the climb "to VFR on top."

You can start off with that request in the remarks section of your flight plan, and your IFR clearance ends as soon as you report reaching VFR on top. Of course, unless you're in Class B, you can't report reaching VFR on top until you're 1000 feet above the cloud layer comprising the ceiling. You've got to be proactive and be the one who asks for it. If ATC knows where those tops are, they'll tell you. They'll also ask you to report if you haven't reached VFR by the time you reach a particular altitude.

Once you're on top, ATC will re-clear you to maintain VFR-on-top. After that point, if you want to remain VFR-on-top, there are some things to remember. See the sidebar at the top of page 10 for a quick list.

But this doesn't always work. If you're the first one punching through that day, and the tops just aren't where area forecasts said they'd be, then what do you do? You might request an amended clearance to some higher altitude, or you might have to contend with a new route, which you're expected to be able to copy and read back, all while you're still climbing in the soup. Alternately, if they give you a clearance limit, you might have to hold there for awhile until they figure out a new game plan (i.e., route) for you. If there's ice where you were hoping to punch through, that's no help. The upshot with this one is, don't use it unless you're fairly sure you'll leave the clouds behind and below you.

ARRIVALS

As for coming back to earth, two strategies can be useful for avoiding lengthy IFR procedures when you get near your destination. One is fairly safe and benign, while the other one is notoriously tricky. The safer of the two is called, quite simply, a visual approach. Either you or the controller can suggest it. In order to fly the "visual," not surprisingly, the weather must be VMC (local ceilings must be at least 1000 feet and visibility must be three statute miles or more, e.g., "marginal VFR"). See the sidebar below left for more visual approach details.

If you report VFR, ATC likely will trust you, in part since it's your neck. Either having the airport or preceding traffic in sight will suffice. Warning: In this situation, fudging can prove non-habit forming. What I mean is that if you get lost in the haze and you don't say so, you're asking for trouble. Be aware here that traffic separation (as well as arrival sequencing to the destination runway) is now your job on this type of approach.

The bad boy of these two "sorta IFR" approaches is the contact approach, also detailed at left. This one you have to ask for, and you can only get it where there is already a published approach. This clearance makes the most sense for traveling between nearby airports or for pilots intimately familiar with the surrounding area.

Again, it's up to you to keep ATC informed on what you can (or can't) see. If in your judgment (or theirs) completing the approach is in doubt, you should accept an alternate clearance. Poor weather, unfamiliar terrain and one mile visibility don't make a safe mix.

How safe these two approaches actually are for allowing reasonable shortcuts to formal and sometimes lengthy approach procedures, as well as how beneficial it might be to take the easy way up through clouds to VFR on top, all depends on how well you adhere to their limitations. In general, if you're a compulsive law abider, stay figuratively "on top" of the weather, and maintain your instrument skills, then these procedures represent an operational advantage, allowing you to save a bit of time as well as money.

STUFF TO WATCH FOR

Of course, there's no free lunch. You can be happily droning along on your "sort of" IFR clearance when, all of a sudden, things take a turn for the worse.

For the folks who usually fly in clear blue skies, clouds represent an approach/ avoidance conflict. When I learned to fly, along with the aesthetic satisfaction of communing with clouds and the growing understanding of what they could tell me, I also realized what they could do to me. This is especially relevant for VFR pilots who take the (still quite legal) opportunity to fly above them.

Being able to experience that ethereal realm between air that we cannot see, and the enchanting beauty of moving sculpture that can take the form of smoothly undulating stratus sheets, or the three-dimensional Rorschach topiary of cumulus canyons and cathedrals, is a truly miraculous gift. But so much for my joyously exultant paean to clouds.

Especially if we're Instrument rated, why might we want to fly VFR above them in the first place? Aside from the initial rapture of surmounting what were formerly your limits to upward vision, you're probably also going to have: a) better visibility, b) better weather, c) a smoother ride and d) more advance notice of challenging weather ahead. You're also likely to have less traffic. The higher you go, the more options you have in the event of a power failure, and of course, when you're literally on top in the daytime, it is quite bright and sunny up there. But unless you have an Instrument rating, you'd better also have a guaranteed cloudless climb to, and cloud-free descent from your cruising altitude, beginning at your departure point and continuing to your destination.

The sidebars on page 11 and above cover some of the things you should look for in your pre-flight briefing and while en route. When VFR-on-top, keeping the "big" weather picture in mind is more important than ever before.

With that in mind, here are some additional things to think about and look for to improve the safety of your VFR-on-top operations:

* After a cold front passes, except where high terrain is a factor (even in the Appalachians) with building high pressure, when you fly over a layer of scattered clouds, you're likely to have a smooth ride. (Go underneath though, and it's likely to be rough as a cob.)

* The eastern side of a high often has descending air, good visibility, scattered clouds, little convection and low tops. On the back side, though, you're more likely to find moisture, rain or possibly thunderstorms (although not usually in the early morning).

* With a low scattered layer situation, such as is typical of Florida, visual avoidance of rain showers is practical and relatively safe (except with a frontal passage or worse, such as a tropical depression).

* In the southwest, particularly in the high desert country, it's usually easy to get above low clouds. Turbulence can be nasty though, especially near the Rockies.

ONE MORE THING

All that is nice to know, isn't it? But, what can you do if, despite your better judgment and prudence, you wind up being stuck up there and can't get down, even if you have an Instrument rating?

Obviously, if convective activity isn't a factor and terrain isn't either, and the cloud bases are high enough, an emergency descent could be done in some relative degree of safety, provided your instrument skills are up to it--and you have an Instrument rating in the first place. Of course, there's always the time-honored "180," followed by a diversion to an airport with good VMC.

Then there's the "find a hole" method. If it's big enough, high enough and you know the terrain is flat enough, sure. But the implications of the phrase "sucker hole" are just as valid (if not more so) on the way down as they are for the trip up. And in case you thought I would forget, before you try any of the above, call ATC first. Don't hesitate for a second to declare an emergency.

And remember those four Cs: Climb, Communicate, Confess and Comply. If you're not Instrument-rated, and make it back down, start work on the rating (after you've finished kissing the ground).

DON'T ABUSE THE PRIVILEGE

It's quite legal to fly VFR on top--that is, in the U.S. And it can be quite safe. But every story has two sides, and the story most every other country has is, don't do it; it's illegal for a VFR pilot in most other places around the world.

Yeah, VFR on top is perfectly okay--maybe. As long as you have a good grounding in weather basics, a healthy skepticism about weather forecasts and you always have contingency plans.

VFR-ON-TOP

"ATC authorization for an IFR aircraft to operate in VFR conditions at any appropriate VFR altitude."--FAA Instrument Flying Handbook

VFR OVER-THE-TOP

"A VFR operation in which an aircraft operates in VFR conditions on top of an undercast."--FAA Instrument Flying Handbook

A VFR Or IFR Clearance?

The FAA's Instrument Flying Handbook, FAA-H-8083-15, is a great reference to learn what you can do (but perhaps not how to do it). What does it say about two frequently confusing operations?

VFR-ON-TOP

"A pilot on an IFR flight plan, operating in VFR conditions, may request to climb/descend in VFR conditions. When operating in VFR conditions with an ATC authorization to "maintain VFR-On-Top/maintain VFR conditions" pilots on IFR flight plans must:

1. Fly at the appropriate VFR altitude as prescribed in part 91.

2. Comply with the VFR visibility and distance-from-cloud criteria in part 91.

3. Comply with IFR rules applicable to this flight (e.g., minimum IFR altitudes, position reporting, radio communications, course to be flown, adherence to ATC clearance, etc.). VFR-On-Top is not permitted in certain areas, such as Class A airspace."

VFR OVER-THE-TOP

"VFR Over-The-Top is strictly a VFR operation in which the pilot maintains VFR cloud clearance requirements while operating on top of an undercast layer.

This situation might occur when the departure airport and the destination airport are reporting clear conditions, but a low overcast layer is present in between. The pilot could conduct a VFR departure, fly over the top of the undercast in VFR conditions, then complete a VFR descent and landing at the destination.

VFR cloud clearance requirements would be maintained at all times, and an IFR clearance would not be required for any part of the flight."--J.B.

Two Sets Of Rules ...

When operating IFR on a VFR-on-top clearance, you need to comply with two sets of rules. Thankfully, they're not really all that contradictory.

ATTITUDES

You can change altitude whenever you want, but you must first inform the controller--just as when VFR and receiving flight following. Also, you're expected to choose from among only VFR cruising altitudes (i.e., your IFR altitude plus 500 feet) based on your magnetic course. Of course, you must fly no lower than the published MEA or MOCA.

ROUTING

You must adhere to the assigned route, except that you also must remain clear of restricted areas. You still have to remain on-frequency and communicating with ATC, and you are ultimately responsible to see and avoid all other traffi c.

WEATHER

Note that you can be "on top" even if there's another layer of clouds above you, such as when you're between layers, or even when all the clouds are above you. You'll have to maintain appropriate distances from clouds--in Class B, it's only "clear of clouds." Also, you must tell ATC if you can no longer remain in VFR conditions. So, yes, you have freedoms, but the price you pay is that you must adhere to two sets of rules.

... And Two Different Approaches

VISUAL APPROACH

A visual approach is an ATC authorization for an aircraft on an IFR flight plan to proceed visually to the airport; it is not an IAP. Also, there is no missed approach segment. A vector for a visual approach may be initiated by ATC if the reported ceiling at the airport of intended landing is at least 500 feet above the MVA/MIA and the visibility is 3 statute miles or greater.

Pilots must remain clear of the clouds at all times while conducting a visual approach.

CONTACT APPROACH

Pilots can request a contact approach: it cannot be initiated by ATC. This procedure may be used as long as the airport has a published or special instrument approach procedure, the reported ground visibility is at least 1 statute mile and the flight can remain clear of clouds. The contact approach allows pilots to retain an IFR clearance and provides separation from IFR and SVFR traffi c. Obstruction clearances and VFR traffi c avoidance becomes the pilot's responsibility.

The main differences between the two approaches are the weather minima and who may initiate a request for the approach.

Planning To Stay On Top

While a VFR-on-top clearance can be used to avoid many of the hassles that come with IFR, few pilots actually plan their cross-country flights with it in mind. Instead, it's usually a spur-of-the-moment thing, designed to resolve one operational challenge or another. And that's a pity, because the clearance can be a useful one. On those flights when you know such a clearance is--or may be--in the offing, spend a little extra planning time before takeoff.

GET A BRIEFING

Always get a comprehensive preflight weather briefing. Look for (or listen for mention of) layers in terminal forecasts. If it's 5000 scattered and 10,000 broken all along your route, fine. If it's 3000 scattered, 6000 broken and 9000 overcast, a front is likely to be nearby.

1000-AND-THREE

VFR-only pilots should look for (and must have) surface reports and forecasts giving VFR beneath the lowest cloud layer, which must be no lower than the 1000-foot VFR ceiling minimum (and that's cutting it close).

LOOK FOR LAYERS

Area forecasts also mention cloud layers. If you see SCT-BKN030 OVC050 CLDS LYRD 150 and you know that you'll be ahead of a warm front, and topping that scattered-to-broken layer isn't likely, settle for VFR underneath.

CHECK PIREPS

Pilot reports are great sources for information on cloud bases and tops. I give them whenever I have half a chance. You should, too. Have a look at AOPA's online "SkySpotter" presentation.

GET AND GIVE UPDATES

And then once you're up there, make use of Flight Watch on 122.0 for updates on surface observations, TAF amendments, and of course, any hot pireps. (After a lower broken layer becomes an undercast isn't the time to call Flight Watch for the nearest airports with VFR ceilings and visibility.)

Staying On Top Of Things

Once you climb on top of an undercast and accept a VFR-on-top clearance, you still have to stay VFR while you're there. And you either have to find some VFR through which you can descend for a landing or request an IFR descent clearance.

Meanwhile, while you're up there cruising around, and marveling at the view, things can and do change: Literally and figuratively, you still have to stay on top of the weather. Here's what to watch for.

BUILDUPS

Clouds tend to grow upward when it gets warmer, as the day progresses. For non-turbocharged aircraft and those without on-board oxygen, you could wind up having to deviate around build-ups at higher and higher altitudes. If the clouds catch up to you, blundering into convective weather that can lie within is a distinct possibility.

SOLID LAYERS

When humidity is high, scattered clouds can rapidly coalesce into broken clouds, and then an overcast layer. Add in frontal movement, orographic lifting towards higher terrain, a marine layer, river valley moisture or lowered temperatures in the morning and evening, and your odds of worry-free on-top operations dwindle drastically.

POOR VISIBILITY

Just because you're on top doesn't mean you won't have to deal with other weather phenomena. Haze is a form of obscuration that can easily top 10,000 feet back east, especially near cities and reduce flight visibility to IMC values.

STIFF WINDS

Climbing on top might buy you a tailwind or one hellacious headwind. Once on top, evaluate your groundspeed and compare it to the fuel you have available. If you can't reach your destination, and can't get an IFR clearance for a descent through the clouds, what will you do?

FRONTAL ACTIVITY

Watch out for fronts! As you get anywhere near them (beginning as far as hundreds of miles away), clouds tend to be layered more. Closer in, layers often merge into IMC, which could put you in a squeeze play. Either way, if you're VFR only, you're tagged out.

Going cross-country means you're going to see changes in cloud formations, unless you're cruising through a big fat high pressure area. (However, cumulus clouds and air mass thunderstorms can form within these, too.)

Jeff Pardo is a freelance writer and editor who holds a Commercial certificate for airplanes, helicopters and sailplanes.
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Title Annotation:Instrument Flight rules; visual flight rules tools
Author:Pardo, Jeff
Publication:Aviation Safety
Geographic Code:1USA
Date:Sep 1, 2006
Words:3275
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