/G & Clearance Void Questions

[GarmAspen]

Hello again. I posted in the summer about upgrading my plane with an Aspen PFD and a Garmin GTN (650). Well, I gone off and done it! I got my plane back a month ago and I absolutely love the new found capability. The biggest challenge was learning how to operate the equipment.

My first question; flying a /A plane the majority of my IFR flying career, the /G capability has opened up some questions on what you can and cannot file. For years I would create a flight plan with low altitude airways and file this. It was not uncommon that in radar coverage I would get off airway routing to the next VOR. What can I expect to get for routing in both radar and non-radar coverage areas? Can I file direct and bypass the airways? Is it smart to do so considering I only have 1 WAAS GPS?

My second question pertains to clearances. I recently moved to a non-controlled airport after being based at a towered field. I have flown out of non-controlled fields before and have received Clearance Void times. However, for the first time I received an actual release time which too me a bit by surprise. Can someone walk me through the types of clearance restrictions I may receive at a non-tower airport? I have read section 5-2-6 of the AIM, but am confused when I may get a "Hold for Release" over a "Release Time" if I am picking up my clearance by phone.

Thanks for the help!

 

[Brad Z]

Hello again. I posted in the summer about upgrading my plane with an Aspen PFD and a Garmin GTN (650). Well, I gone off and done it! I got my plane back a month ago and I absolutely love the new found capability. The biggest challenge was learning how to operate the equipment.

My first question; flying a /A plane the majority of my IFR flying career, the /G capability has opened up some questions on what you can and cannot file. For years I would create a flight plan with low altitude airways and file this. It was not uncommon that in radar coverage I would get off airway routing to the next VOR. What can I expect to get for routing in both radar and non-radar coverage areas? Can I file direct and bypass the airways? Is it smart to do so considering I only have 1 WAAS GPS?

My second question pertains to clearances. I recently moved to a non-controlled airport after being based at a towered field. I have flown out of non-controlled fields before and have received Clearance Void times. However, for the first time I received an actual release time which too me a bit by surprise. Can someone walk me through the types of clearance restrictions I may receive at a non-tower airport? I have read section 5-2-6 of the AIM, but am confused when I may get a "Hold for Release" over a "Release Time" if I am picking up my clearance by phone.

Thanks for the help!

Question #1: File what you want. No harm in filing direct if that's how you want to go. In the Northeast, you won't get it though.

Question #2:

Hold For Release: means you don't have a release. You'll get that if you're calling ATC just to pick up your clearance routing. You might wait until you're out at the runway holdshort area to call back for your clearance. Alternatively you could tell them at the time you pick up your clearance that you'll be ready to go in 10 minutes, or whatever.

A release consists of three times:

A release time- don't take off before it.
A Void time- don't take off after it.
A notification time- if you are not able to take off, please call before this time.

The release will also include any ATC instructions and altitude restrictions, such as "enter controlled airspace heading 180 climb and maintain 2000"

It's pretty simple really. At a non-towered field, ATC needs to make a hole in the sky for you, but they can't leave the hole in the controlled airspace open forever.

 

[poadeleted20]

My first question; flying a /A plane the majority of my IFR flying career, the /G capability has opened up some questions on what you can and cannot file. For years I would create a flight plan with low altitude airways and file this. It was not uncommon that in radar coverage I would get off airway routing to the next VOR. What can I expect to get for routing in both radar and non-radar coverage areas?

It's more an issue of traffic density than availability of radar coverage. In the Northeast Corridor, even with radar coverage, you're still going to get the TEC routes even with GPS because that's the only way they can keep you out of the arrival/departure corridors of all the big airline airports. OTOH, out in South Dakota, GPS direct routes are no problem at all. So, file direct if you wish, but be prepared for the preferred/TEC routes, especially in high density areas.

Is it smart to do so considering I only have 1 WAAS GPS?

Not an issue -- if the GPS dies, you can get a new on-airways clearance pretty fast.

My second question pertains to clearances. I recently moved to a non-controlled airport after being based at a towered field. I have flown out of non-controlled fields before and have received Clearance Void times. However, for the first time I received an actual release time which too me a bit by surprise. Can someone walk me through the types of clearance restrictions I may receive at a non-tower airport? I have read section 5-2-6 of the AIM, but am confused when I may get a "Hold for Release" over a "Release Time" if I am picking up my clearance by phone.

You can think of the void time as the closing of the window -- either you get through it by then or you stay in the room until it opens again. Likewise, a release time is the opening of that window -- you can't go through until the window opens, and then you have only a limited time until it closes again (void time). Usually, your release window is opened as you receive the release, but sometimes ATC has a reason for giving you a delayed release like that. The key is recognizing that it's a window of opportunity which may not open immediately upon receipt of your release, and you have to wait on the ground until it does.

 

[GarmAspen]

Thanks for the replies. I like your analogy of the windows Ron. Makes it easy to understand.

Are the TEC routes published somewhere? Do the TEC routes have specific altitudes limits? In other words, if I file high enough, will I get different routing?

 

[roncachamp]

My first question; flying a /A plane the majority of my IFR flying career, the /G capability has opened up some questions on what you can and cannot file. For years I would create a flight plan with low altitude airways and file this. It was not uncommon that in radar coverage I would get off airway routing to the next VOR. What can I expect to get for routing in both radar and non-radar coverage areas? Can I file direct and bypass the airways? Is it smart to do so considering I only have 1 WAAS GPS?

In a radar environment you can be cleared direct. In a nonradar environment you will be routed via airways or traditional NAVAIDs. The GPS still gives an advantage in a nonradar environment as the NAVAIDs don't have to be operational, except in ZBW airspace.

My second question pertains to clearances. I recently moved to a non-controlled airport after being based at a towered field. I have flown out of non-controlled fields before and have received Clearance Void times. However, for the first time I received an actual release time which too me a bit by surprise. Can someone walk me through the types of clearance restrictions I may receive at a non-tower airport? I have read section 5-2-6 of the AIM, but am confused when I may get a "Hold for Release" over a "Release Time" if I am picking up my clearance by phone.

You get a hold for release if you can't be immediately released due to other traffic or if you don't intend to depart for a while. Issuing the clearance without one makes it valid upon issuance.

 

[jordane93]

Thanks for the replies. I like your analogy of the windows Ron. Makes it easy to understand.

Are the TEC routes published somewhere? Do the TEC routes have specific altitudes limits? In other words, if I file high enough, will I get different routing?

they can be found in the back of the AFD, all airports do not have TEC routes. they will list the airport, the routing, any limitations (single engine only, turbo prop only, /G only, etc), highest altitude and destination. if your airport isnt listed, look for airports close to you and check out theirrouting because it will be similar to what you get. i fly out of KFRG and havent even bothered to file direct. i use TEC routes and sometimes dont. controllers are accomidating though. snd soemtiems will give you direct to your destination after crossing over your first few fixes in the tec route

 

[poadeleted20]

Are the TEC routes published somewhere?

Yes -- Northeast A/FD for the ones covering Maine to Virginia. For the SoCal TEC routes, I think they're in the California A/FD, as well as the LA Center web site. Not sure where to find the Bay Area TEC routes for NorCal.

Do the TEC routes have specific altitudes limits?

Yes, they do -- the top of the TRACON airspace, generally about 8000 MSL in the Northeast TEC system.

In other words, if I file high enough, will I get different routing?

Yes. Above the top of the Northeast TEC system (8000 or so), you'll get the regular low-altitude preferred routes in the A/FD (which all show their altitude ranges as 090-170 or something close to that).

 

[bobmrg]

Thanks for the replies. I like your analogy of the windows Ron. Makes it easy to understand.

Are the TEC routes published somewhere? Do the TEC routes have specific altitudes limits? In other words, if I file high enough, will I get different routing?

AIM 4-1-19 answers the altitude question. TEC routes used to be in the back of the A/FD, but I can't find them now. Anyway, there are/were far more city pairs than were listed...as long as you stay within TRACON airspace you can get TEC any two airports. Try putting TEC in the remarks section of your flight plan.

Bob Gardner

 

[poadeleted20]

AIM 4-1-19 answers the altitude question. TEC routes used to be in the back of the A/FD, but I can't find them now.

In the Northeast A/FD, check the ToC for "Routes/Waypoints". If you get your A/FD on ForeFlight, you'll need to download the Supplemental Data for that region in the Documents section.

 

[cirrusmx]

so when in doubt, file direct and get automatically route? sounds convenient.

 

[poadeleted20]

so when in doubt, file direct and get automatically route? sounds convenient.

It might be convenient in some ways, but it can be a bit of a problem if you start the engine, call for clearance, and get something completely unlike anything you had any idea you might get. The cockpit really isn't a very good place to be flight planning -- or re-planning. I may file direct, but I've always checked to see what non-direct routing I'm likely to get if direct isn't happening today and made sure I can handle it without any further prior warning.

 

[jordane93]

It might be convenient in some ways, but it can be a bit of a problem if you start the engine, call for clearance, and get something completely unlike anything you had any idea you might get. The cockpit really isn't a very good place to be flight planning -- or re-planning. I may file direct, but I've always checked to see what non-direct routing I'm likely to get if direct isn't happening today and made sure I can handle it without any further prior warning.

yep. this exactly. if you file direct always study another route just to play it safe in case you dont get it.

 

[poadeleted20]

That said, I must say that it's a lot easier to figure out a new route clearance in the cockpit with ForeFlight than with paper charts. Technology really does have its advantages.

 

[Brad Z]

One I'll mention about filing direct is to make sure it's a flyable route, from routing or airspace perspective. I'll often file direct back to my home field outside of ATC. Often I'll get it. Once I filed direct from Niagara to VKX. I filed direct because I wasn't sure which way Potomac would take me around the FRZ. When I called for my clearance, I got "cleared as filed". Of course I eventually got a reroute, but I couldn't help but think what I might do in a lost comms situation. Lost comms procedure are pretty cut and dry, but flying direct would take me directly over the White House...that's a no go NORDO or otherwise.

 

[Bill Watson]

I've found when that when getting a clearance by phone for TO at my home 'port, how I answer the question, "When will you be ready to go?" often determines whether I'll get a release time. If I say I'm ready to go immediately or in 5 mins, I usually don't get a release time and a +10 minute void time. Conversely, when I used to say 10 mins (pre-FF and an A/P) I would usually get a release time (and void time).

 

[flyingron]

That said, I must say that it's a lot easier to figure out a new route clearance in the cockpit with ForeFlight than with paper charts. Technology really does have its advantages.

Or with a decent IFR GPS. 99% of the clearances (even in the contorted north east) are directly acceptable by the FPL page on my GPS. It's only if they intersect airways at other than published fixes that I need to really look at a map.

 

[John Collins]

A new capability is available in the non radar environment for GPS equipped aircraft. It used to be the rule in the CONUS that a random GPS route (a random route is an uncharted route) required that the aircraft be monitored by radar. Effective 10/24/13, this is no longer the case if certain conditions are met. The route must be a "Point to Point" random route. This is defined as the great circle route between two points that can be loaded from the database by name. Each segment can't be longer than 500 NM. The assigned altitude must be at or above the MIA (Minimum IFR altitude). The MIA along a point to point random route is 1000 feet above (2000 feet in mountainous areas) the highest obstacle or terrain within +/- 4 NM of the centerline of the route. A route direct-to a waypoint or fix is termed an impromptu random route. An impromptu random route requires radar monitoring. For example, if you request an airport direct airport route and are cleared as such, but during the departure procedure end up some distance from the route centerline, you will have to get reestablished along the cleared route before you can be non radar.

Some of this was released early this year to overcome issues with aircraft being outside of the service volume of ground based Navaids and is probably the biggest application of this guidance change. Even though this guidance is in effect, it will probably take a while before it will be available due to its newness and by and large controllers haven't been trained.

 

[aterpster]

A new capability is available in the non radar environment for GPS equipped aircraft. It used to be the rule in the CONUS that a random GPS route (a random route is an uncharted route) required that the aircraft be monitored by radar. Effective 10/24/13, this is no longer the case if certain conditions are met. The route must be a "Point to Point" random route. This is defined as the great circle route between two points that can be loaded from the database by name. Each segment can't be longer than 500 NM. The assigned altitude must be at or above the MIA (Minimum IFR altitude). The MIA along a point to point random route is 1000 feet above (2000 feet in mountainous areas) the highest obstacle or terrain within +/- 4 NM of the centerline of the route. A route direct-to a waypoint or fix is termed an impromptu random route. An impromptu random route requires radar monitoring. For example, if you request an airport direct airport route and are cleared as such, but during the departure procedure end up some distance from the route centerline, you will have to get reestablished along the cleared route before you can be non radar.

Some of this was released early this year to overcome issues with aircraft being outside of the service volume of ground based Navaids and is probably the biggest application of this guidance change. Even though this guidance is in effect, it will probably take a while before it will be available due to its newness and by and large controllers haven't been trained.

John,

Do you have a cite for this change?

Who is responsible for calculation the MIA for such a direct route (4 miles each side of centerline) the pilot or ATC?

And, the term "MIA" is a bit different for centers than it is for pilots. Center MIAs are polygons and, in some cases they have somewhat less than 2,000 feet of obstacle clearance in Designated Mountainous Areas.

91.177 places an absolute responsibility on the pilot to have not less than 2,000 feet of obstacle clearance 4 miles each side of centerline (more correctly 4 miles in all four directions) when not on a PART 95 or 97 route. By practice ("unless otherwise authorized by the FAA") center MIAs are considered the equivalent of Part 95 routes although, in fact, they are not.

 

[BobThePilot]

so when in doubt, file direct and get automatically route? sounds convenient.

I never file direct unless I am pretty sure I can get it. I learned my lesson when flying from a major airport in the northeast. I filed direct and got the email clearance that said "DIRECT", but when I called for my clearance I got a HUGE routing that looked like a full departure with all the intersections. Almost like someone was "punishing" me for even asking for a direct. I had to ask for all the VOR's to be spelled out, and had to deal with that complicated route in a busy part of the country without any pre planning. Sure enough the amended routing came through on my email later but too late.

 

[flyingron]

I never file direct unless I am pretty sure I can get it. I learned my lesson when flying from a major airport in the northeast.

Mind you, DIRECT really do isn't the problem. I pretty much field OWD V3 MRB CJR. This is a routing that would appear to take you well west of NYC etc... Well the computer takes it fine, but CD at OWD says "yeah that's not going to work....got your pencil ready." Zigzag from several named fixes, out over long island sound to a VOR, direct JFK (later amended to intercept a random JFK radial) and then on airways down to the eastern shore of VA and then direct IAD (note the airport not the collocated VOR called AML).

Fortunately by the time I got down to the Eastern Shore, they gave me a more sane routing through the DC area.

Other fun and games in Maine.

This is opposed to having filed an airway route out of central NC and getting:
GSO: 5327K are you /G?
27K: Affirmative.
GSO: Proceed direct CJR.

 

[John Collins]

John,

Do you have a cite for this change?

Who is responsible for calculation the MIA for such a direct route (4 miles each side of centerline) the pilot or ATC?

And, the term "MIA" is a bit different for centers than it is for pilots. Center MIAs are polygons and, in some cases they have somewhat less than 2,000 feet of obstacle clearance in Designated Mountainous Areas.

91.177 places an absolute responsibility on the pilot to have not less than 2,000 feet of obstacle clearance 4 miles each side of centerline (more correctly 4 miles in all four directions) when not on a PART 95 or 97 route. By practice ("unless otherwise authorized by the FAA") center MIAs are considered the equivalent of Part 95 routes although, in fact, they are not.

Good questions. See attached order 7110.639

View attachment 7110.639 gps.pdf

 

[poadeleted20]

Or with a decent IFR GPS. 99% of the clearances (even in the contorted north east) are directly acceptable by the FPL page on my GPS. It's only if they intersect airways at other than published fixes that I need to really look at a map.

A "decent IFR GPS" isn't going to show you overwater legs, SUA's, TFR's, etc., nearly as readably as a good EFB like ForeFlight. Not even your GNS480, FRon -- the screen isn't big enough or detailed enough.

And yes, I know your definition of "a decent IFR GPS" is the one which includes airways and excludes the Garmin 400/500-series. The fact that over 100,000 of the latter have been sold and yours was discontinued with only a fraction of that production suggests most folks disagree with your characterization.

 

[flyingron]

A "decent IFR GPS" isn't going to show you overwater legs, SUA's, TFR's, etc., nearly as readably as a good EFB like ForeFlight. Not even your GNS480, FRon -- the screen isn't big enough or detailed enough.

Yes but I have an MX20 as well with XM weather.

And yes, I know your definition of "a decent IFR GPS" is the one which includes airways and excludes the Garmin 400/500-series. The fact that over 100,000 of the latter have been sold and yours was discontinued with only a fraction of that production suggests most folks disagree with your characterization.

Now you're going off and inserting things that I never said. If you need an iPad to supplement your older Garmin unit, fine. But even the CURRENT GTN units as well as the flight deck will do all of this as well.

A bit defensive are we? I never said your 430 sucked, or maligned your use of the iPAD. I just pointed out that an IFR GPS can accomplish the task as well.

 

[poadeleted20]

Now you're going off and inserting things that I never said. If you need an iPad to supplement your older Garmin unit, fine. But even the CURRENT GTN units as well as the flight deck will do all of this as well.

Not, they won't, at least not without something like a G500 for displaying the route.

I just pointed out that an IFR GPS can accomplish the task as well.

Not by itself.

 

[aterpster]

Good questions. See attached order 7110.639

View attachment 32209

Thanks John.

A quick read tells me ATC is responsible for obstacle clearance and must use the highest center MIA along the route.