IFR in Class G airpace

[Gary F]

I'm not so sure that's the correct reference for what governs pilot conduct. Especially in uncontrolled airspace where ATC provides no services.

Might as well look at the Illinois statutes to figure out what the law is in Massachusetts.

The FAA controller handbook gives a condensed list of the basic requirements. So what is it you think I am missing? The high Class G areas here are relatively flat with few obstructions, certainly nothing nearly as high as I would fly. A couple of grass strips exist in these areas but no approaches and I do not intend to land. ATC is not involved. What is this IFR boogey man you want me to watch out for? Got an example?

 

[John Collins]

I'm not so sure that's the correct reference for what governs pilot conduct. Especially in uncontrolled airspace where ATC provides no services.

Might as well look at the Illinois statutes to figure out what the law is in Massachusetts.

ATC is not required to provide services in uncontrolled airspace, but they may, if requested by the pilot. They may provide vectors in uncontrolled airspace as an additional service and they may clear an aircraft into or thru uncontrolled airspace. Of course, they have to have radar coverage available at the altitude in question in order to provide vectors. In the future, with ADSB, surveillance capabilities could be expanded to areas that don't have radar coverage, particularly in mountainous regions.

 

[midlifeflyer]

The FAA controller handbook gives a condensed list of the basic requirements. So what is it you think I am missing? The high Class G areas here are relatively flat with few obstructions, certainly nothing nearly as high as I would fly. A couple of grass strips exist in these areas but no approaches and I do not intend to land. ATC is not involved. What is this IFR boogey man you want me to watch out for? Got an example?

What Bogey man are you talking about. I'm not aware of one.

All I'm saying is that if you think the best source of information on the rules that govern pilot operations in uncontrolled airspace is the guide for controllers providing services in controlled airspace, I disagree.

 

[aterpster]

ATC is not required to provide services in uncontrolled airspace, but they may, if requested by the pilot. They may provide vectors in uncontrolled airspace as an additional service and they may clear an aircraft into or thru uncontrolled airspace. Of course, they have to have radar coverage available at the altitude in question in order to provide vectors. In the future, with ADSB, surveillance capabilities could be expanded to areas that don't have radar coverage, particularly in mountainous regions.

The way I understand those provisions they would be associated with an aircraft on an IFR flight plan departing controlled airspace or entering controlled airspace. If Farmer Jones wants to operate solely within one of "those big brown areas" I am uncertain ATC would provide any services.

 

[TangoWhiskey]

It's also impossible in the 1200' AGL Class E areas as your cruising altitude must be a cardinal altitude correct for your direction of flight.

Those cardinal altitudes apply to flights above 3000' AGL... Or is that rule only for VFR cruising altitudes? Off to look it up...

 

[Mike I]

Those cardinal altitudes apply to flights above 3000' AGL.

There's no specification for that only applying above 3000' when IFR.

From 91.159

...each person operating an aircraft under VFR in level cruising flight more than 3,000 feet above the surface shall maintain the appropriate altitude or flight level prescribed below, unless otherwise authorized by ATC:
(a) When operating below 18,000 feet MSL and—
(1) On a magnetic course of zero degrees through 179 degrees, any odd thousand foot MSL altitude +500 feet (such as 3,500, 5,500, or 7,500); or

From 91.179(b) pertaining to Instrument Flight:

(b) In uncontrolled airspace. Except while in a holding pattern of 2 minutes or less or while turning, each person operating an aircraft under IFR in level cruising flight in uncontrolled airspace shall maintain an appropriate altitude as follows:
(1) When operating below 18,000 feet MSL and—

(i) On a magnetic course of zero degrees through 179 degrees, any odd thousand foot MSL altitude (such as 3,000, 5,000, or 7,000); or

(ii) On a magnetic course of 180 degrees through 359 degrees, any even thousand foot MSL altitude (such as 2,000, 4,000, or 6,000).

 

[milkman dan]

So if you are on a course of 350 at 060, you arent worried about somebody being on a course of 190 at 060 also? You're pretty much head on with a minimum 200kt closure rate. Even in 1sm visibility, thats really not enough time to perform an evasive maneuver.
What about the guy who got a departure clearance from his grass strip through your altitude?

 

[John Collins]

The way I understand those provisions they would be associated with an aircraft on an IFR flight plan departing controlled airspace or entering controlled airspace. If Farmer Jones wants to operate solely within one of "those big brown areas" I am uncertain ATC would provide any services.

From 7110.65U (emphasis is mine):

4−4−5. CLASS G AIRSPACE
Include routes through Class G airspace only when requested by the pilot.
NOTE−
1. Flight plans filed for random RNAV routes through Class G airspace are considered a request by the pilot.

I have used this several years back to obtain a direct clearance which transited thru a large size high (up to 14500 MSL) Class G area on a flight between FMN (Four Corners, NM) and 1L9 (Parowan, UT).

From 7110.65U (emphasis is mine) :

5−6−1. APPLICATION
Vector aircraft:
a. In controlled airspace for separation, safety, noise abatement, operational advantage, confidence maneuver, or when a pilot requests. Allow aircraft operating on an RNAV route to remain on their own navigation to the extent possible.
b. In Class G airspace only upon pilot request and as an additional service.

If I recall, at our altitude, we were in radar coverage for much of the flight in the class G, but did not request or receive any vectors.

From the Pilot/Controller Glossary (emphasis is mine):

CRUISE− Used in an ATC clearance to authorize a pilot to conduct flight at any altitude from the minimum IFR altitude up to and including the
altitude specified in the clearance. The pilot may level off at any intermediate altitude within this block of airspace. Climb/descent within the block is to be made at the discretion of the pilot. However, once the
pilot starts descent and verbally reports leaving an altitude in the block, he/she may not return to that altitude without additional ATC clearance. Further, it is approval for the pilot to proceed to and make an approach at destination airport and can be used in conjunction with:
a. An airport clearance limit at locations with a standard/special instrument approach procedure. The CFRs require that if an instrument letdown to an
airport is necessary, the pilot shall make the letdown in accordance with a standard/special instrument approach procedure for that airport, or
b. An airport clearance limit at locations that are within/below/outside controlled airspace and without a standard/special instrument approach procedure. Such a clearance is NOT AUTHORIZATION for the pilot to descend under IFR conditions below the applicable minimum IFR altitude nor does it imply that ATC is exercising control over aircraft in Class G airspace; however, it provides a means for the aircraft to proceed to destination airport, descend, and land in accordance with applicable CFRs governing VFR flight operations. Also, this provides search and rescue protection until such time as the IFR flight plan is closed.

I interpret this to mean that I can file for an airport in class G and get it as the clearance limit and descend to the minimum IFR altitude, but would have to be VFR to continue the descent to my destination. Note that Parowan does not have any approaches and is under class G up to 1200 AGL.

 

[Gary F]

So if you are on a course of 350 at 060, you arent worried about somebody being on a course of 190 at 060 also? You're pretty much head on with a minimum 200kt closure rate. Even in 1sm visibility, thats really not enough time to perform an evasive maneuver.
What about the guy who got a departure clearance from his grass strip through your altitude?

I'm not, at least in the Class G airspace around here. The traffic density is so very low anywhere in the U.P. it is highly improbable for two aircraft to occupy the same space at the same time especially in the more remote areas.

 

[aterpster]

I interpret this to mean that I can file for an airport in class G and get it as the clearance limit and descend to the minimum IFR altitude, but would have to be VFR to continue the descent to my destination. Note that Parowan does not have any approaches and is under class G up to 1200 AGL.

Absolutely.

 

[pericynthion]

Unfortunately the minimum IFR altitude at Parowan is inconveniently high - a practical alternative might be to shoot an approach into nearby CDC, and then fly the other sort of IFR (I Follow Roads) along the interstate to Parowan.

 

[weilke]

So if you are on a course of 350 at 060, you arent worried about somebody being on a course of 190 at 060 also? You're pretty much head on with a minimum 200kt closure rate. Even in 1sm visibility, thats really not enough time to perform an evasive maneuver.
What about the guy who got a departure clearance from his grass strip through your altitude?

The reason those 'big brown areas' exist is that practically nobody lives there. The odds of another aircraft being in the same wedge of high class G are slim to none, the odds of another fool poking around in the clouds in the same wedge of high class G are unmeasurable.

 

[aterpster]

The reason those 'big brown areas' exist is that practically nobody lives there. The odds of another aircraft being in the same wedge of high class G are slim to none, the odds of another fool poking around in the clouds in the same wedge of high class G are unmeasurable.

That was never the basis for Class G airspace. It was the lack of IFR airports, not people per se, although there is an indirect relationship.

In a different era there were three stratums of airspace, high, intermediate, and low. Only the low filled out in the east and the population centers of the west coast.

Then, they went to high and low and someone at the Puzzle Palace decided all airspace 14,500 and above, up to the base of Class A, should be known as the Continental Control Area, which extended upwards to the base of Positive Controlled Airspace (Now Class A), which had a floor of 24,000.

Then, circa 1965 the floor of PCA was lowered to 18,000 rendering the Continental Control Area mostly useless. Why didn't they just lower PCA to 14,500? "No way" the Puzzle Palace gurus decided. 18,000 feet was predicated on the high mountains in the Rockies and the west coast.

In the past 15, or so years, the advent of GPS-based RNAV has made possible instrument approach procedures at airports that previously had no IAPs. No IAPs means VFR airport. But, when one or more IAPs is established beneath the remnants of the Continental Control Area the Class E airspace must be lowered to 1,200, agl (controlled airspace extensions), to contain all segments of the IAP, except closer to the airport it must be lowered to 700, agl (transition areas). Where commuter airline service is provided, then a Class E Surface Area is often established closer to the airport; provided it has communications with ATC to the surface (FSS works for this) and weather reporting service.

Thus, the brown areas are slowly growing smaller. But, the FAA won't extend control area extensions any further than is (in their narrow view) necessary, so now we have many chunks of meaningless little brown areas.

The big brown areas around KBCE and U55 (Utah) disappeared two years ago when those two airports became IFR airports.

The brown areas around Dillon, Montana will shrink because that IFR airport is getting two new RNAV IAPs. The same for Eureka, Nevada, which is in about as people-less area as you get in the lower 48.

Roundup, Montana, presently a VFR airport, is getting two RNAV IAPs this summer, both with TAAs. TAAs require a lot of Class E airspace. The Roundup area has only small "artifact" chunks of the former Continental Control Area, but it has a lot of that "nether-nor" airspace, some with bases of 10,000, and some at 6,700 (both well above 1,200, agl).

A lot of people in the business feel that all remaining Class E airspace that is higher than 1,200, agl, should be brought down to 1,200. But, the gurus at the Puzzle Palace apparently feel that would cause too much controversy in the rule-making that would be required.

But, when they whittle away at it piecemeal, often the NPRMs receive no comments at all.

 

[Gary F]

What Bogey man are you talking about. I'm not aware of one.

All I'm saying is that if you think the best source of information on the rules that govern pilot operations in uncontrolled airspace is the guide for controllers providing services in controlled airspace, I disagree.

Several here have suggested that it is easy to violate regs when flying under IFR in high Class G. I don't really think so. I am IFR current and the airplane meets all regs as far as I know. I fly IFR in IMC on occasion so I am familiar with at least the fundamentals. I think that I can buzz around cumulus clouds at an appropriate IFR altitude over 3,000 ft with minimal hassle by not involving ATC but I like the block altitude sector clearance that Steven and Captain have suggested. What regs do you think I am likely to violate by doing this? I think we have established that it is legal. I also have a Zaon PCAS which should help alert me to the presence of any traffic in the vicinity which is extremely unlikely.

 

[pericynthion]

It's legal. Go drill some holes in those clouds.

 

[Captain]

And again, careful you don't tumble those gyros IMC.

 

[weilke]

I think that I can buzz around cumulus clouds at an appropriate IFR altitude over 3,000 ft with minimal hassle by not involving ATC but I like the block altitude sector clearance that Steven and Captain have suggested.

It is my understanding that they can't give you a 'clearance' for anything in the brown boxes. They can give you a transponder code and not route any off-airways traffic through the box, they can also tell you if there is another kid playing in your sandbox, but they can't 'clear' you to do something outside of controllable airspace.
If you are willing to talk to ATC, you might as well do this in controlled airspace. It is done for IFR training all the time.

 

[Gary F]

And again, careful you don't tumble those gyros IMC.

I don't intend to do any unusual attitude flying, mostly cloud surfing close to but not into the clouds. I will be careful.

 

[Gary F]

It is my understanding that they can't give you a 'clearance' for anything in the brown boxes. They can give you a transponder code and not route any off-airways traffic through the box, they can also tell you if there is another kid playing in your sandbox, but they can't 'clear' you to do something outside of controllable airspace.
If you are willing to talk to ATC, you might as well do this in controlled airspace. It is done for IFR training all the time.

If I do the sector block altitude thing it will be in controlled airspace as Steven suggested.

It's not uncommon and it's easy to do where traffic is light. "Cleared to fly northeast of Sawyer VORTAC between three four zero and zero seven zero radials within four zero mile radius, maintain block four thousand through one zero thousand."

 

[Henning]

And again, careful you don't tumble those gyros IMC.

How is that different in IMC on your own than with ATC?

 

[John Collins]

Several here have suggested that it is easy to violate regs when flying under IFR in high Class G. I don't really think so. I am IFR current and the airplane meets all regs as far as I know. I fly IFR in IMC on occasion so I am familiar with at least the fundamentals. I think that I can buzz around cumulus clouds at an appropriate IFR altitude over 3,000 ft with minimal hassle by not involving ATC but I like the block altitude sector clearance that Steven and Captain have suggested. What regs do you think I am likely to violate by doing this? I think we have established that it is legal. I also have a Zaon PCAS which should help alert me to the presence of any traffic in the vicinity which is extremely unlikely.

It should be legal if you follow all the appropriate regulations. However, your Zaon will only help you avoid traffic if you and they are in radar coverage and using their transponder, as it is not an active system.

 

[Gary F]

It should be legal if you follow all the appropriate regulations. However, your Zaon will only help you avoid traffic if you and they are in radar coverage and using their transponder, as it is not an active system.

I am more worried about hitting an eagle as I almost did flying a 152 near Iron Mountain Michigan a few years ago. It's real lonely up here. Visit us and see for yourself.

 

[gismo]

Not legal. You cannot roll your own instrument approach under any circumstances without violating 91.175 and Part 97.

In Class G you can depart on a roll your own departure, climb to a legal IFR altitude and from that point on you must remain at or above the minimum legal IFR altitude at all times until (if) you become VFR or obtain an IFR clearance from ATC to enter controlled airspace.

Seems like there might be some wiggle room in 91.175:

"...when it is necessary to use an instrument approach to a civil airport..."

If the point of intended landing isn't a registered "civil airport" 91.157 wouldn't apply and even if your private strip was listed by the FAA as an airport would the rule apply if you were already (legally) in class G on your own? I think one could argue in that case the use of an approach wasn't "necessary", just "beneficial" (not that I'm about to try this).

 

[Henning]

Seems like there might be some wiggle room in 91.175:

"...when it is necessary to use an instrument approach to a civil airport..."

If the point of intended landing isn't a registered "civil airport" 91.157 wouldn't apply and even if your private strip was listed by the FAA as an airport would the rule apply if you were already (legally) in class G on your own? I think one could argue in that case the use of an approach wasn't "necessary", just "beneficial" (not that I'm about to try this).

I personally think they should just keep handling it the way its done, seems to work, nobody complains and PIC bears all responsibility.

 

[aterpster]

Seems like there might be some wiggle room in 91.175:

"...when it is necessary to use an instrument approach to a civil airport..."

If the point of intended landing isn't a registered "civil airport" 91.157 wouldn't apply and even if your private strip was listed by the FAA as an airport would the rule apply if you were already (legally) in class G on your own? I think one could argue in that case the use of an approach wasn't "necessary", just "beneficial" (not that I'm about to try this).

Perhaps, but how do you dispose of 91.177?

 

[aterpster]

I personally think they should just keep handling it the way its done, seems to work, nobody complains and PIC bears all responsibility.

Who is "they" in this case?

 

[pericynthion]

Perhaps, but how do you dispose of 91.177?

Sec. 91.177 — Minimum altitudes for IFR operations.

(a) Operation of aircraft at minimum altitudes. Except when necessary for takeoff or landing, ...

?

 

[Henning]

Who is "they" in this case?

ATC in N Tx. It just happens, very rarely BTW, nobody likes using their RYO really, sometimes it's just worth it and it's always nice to have 'in your back pocket' for whatever may come up.

 

[roncachamp]

Those cardinal altitudes apply to flights above 3000' AGL... Or is that rule only for VFR cruising altitudes? Off to look it up...

There in no relief from the hemispheric rule within 3000' of the surface for IFR operations.

 

[Captain]

How is that different in IMC on your own than with ATC?

It's not. I sort of envisioned him wanting to go off on his own to really yank and bank in the soup. I'd feel real bad if he did and tumbled his gyros. Now it sounds like he just want to play by kissing the clouds and leap in and out of 'em.

 

[TangoWhiskey]

From IPH:

OFF ROUTE OBSTRUCTION CLEARANCE ALTITUDE
An off-route obstruction clearance altitude (OROCA) is an off-route altitude that provides obstruction clearance with a 1,000-foot buffer in non-mountainous terrain areas and a 2,000-foot buffer in designated mountainous areas within the U.S. This altitude may not provide signal coverage from ground-based navigational aids, air traffic control radar, or communications coverage. OaROCAs are intended primarily as a pilot tool for emergencies and situational awareness. OROCAs depicted on NACO en route charts do not provide you with an acceptable altitude for terrain and obstruction clearance for the purposes of off-route, random RNAV direct flights in either controlled or uncontrolled airspace. OROCAs are not subject to the same scrutiny as MEAs, MVAs, MOCAs, and other minimum IFR altitudes. Since they do not undergo the same obstruction evaluation, airport airspace analysis procedures, or flight inspection, they cannot provide the same level of confidence as the other minimum IFR altitudes.

Thanks. The highlighted portion is notable.

Wow, no joke!

OROCA is, by acronym, an OFF ROUTE OBSTRUCTION CLEARANCE ALTITUDE... but the fine print says it does NOT provide acceptable obstruction clearance when you're... Wait for it... Off route.

Tell me how the hell that makes any sense?!

Sounds like a great hangar flying or stump-the-applicant question. Still, I don't get it. If what they are implying is that OROCAs are guaranteeing clearance off PUBLISHED routes (outside the 4nm either side course width), then the text should indicate how far beyond the 8nm the OROCA coverage extends.

 

[Henning]

Wow, no joke!

OROCA is, by acronym, an OFF ROUTE OBSTRUCTION CLEARANCE ALTITUDE... but the fine print says it does NOT provide acceptable obstruction clearance when you're... Wait for it... Off route.

Tell me how the hell that makes any sense?!

Sounds like a great hangar flying or stump-the-applicant question. Still, I don't get it. If what they are implying is that OROCAs are guaranteeing clearance off PUBLISHED routes (outside the 4nm either side course width), then the text should indicate how far beyond the 8nm the OROCA coverage extends.

Because it does not survey to a degree of confidence, or have the measured clearances required by a TERPS evaluation of safe clearance. IOW, it may be exact clearance. That would be my thoughts on it.