Icing encounter, ATC negotiation, MVAs that are higher than MEAs in an area

[DXB]

7 hours ago, thinwing said:

i had a pretty bad icing encounter in British Columbia approaching yukon border ..cleared for my alitude but out of radar AND center radio coverage.The difference is I had a little TKS fluid on board but not like i usually carry as this was a summer trip.The one thing i notice on your flight aware track file ,is your aircraft passing through a cell just before your hard turn deviation.I am assuming you had satalite nexrad and also saw that cell.The only thing i would comment on ,is my icing experience occurs inside paintable cells and I would probably asked fro a deviation before cell penetration...

Yeah I wondered about that too when I looked at the Flightaware picture after landing, which I think may not convey the weather that was there at the moment I was at a particular position on the route.  On the ads-b picture, it was just the same light green that I'd been in and out of the whole flight up until that point - boy did a 1000 ft higher make a difference though for icing.

[DXB]

2 hours ago, RobertGary1 said:

The attitude cleared to is just the first leg. Rarely have I had it the final. But I’m out west where we have real mountains 

This is a compelling point and not one I've been forced to think about operationally as a non-turbo east coast lowlander...until now. I can't recall a single instance where I've been forced higher on my entire route than the altitude in my clearance, and there was no terrain that seemed to justify that being needed, so I was mentally unprepared.  Also I thought I was on my first leg (direct DNY) unless you count the assigned departure procedure as the first leg, which was simply fly RWY 33 heading at a minimum climb rate until I was given direct DNY - I suppose that 6000 really only applied to the departure procedure? 

Edited October 19, 2021 by DXB

[RobertGary1]

1 hour ago, philip_g said:

The mva is often less than the mea

Might have said that backwards but you should be good at the mea on airways. 

[DXB]

Thanks for input everyone! Several good discussion points here.  It does seem like detailed graphical access to MVAs would be a big advancement.  In an era when navigation is dominated by WAAS GPS, thinking about MEAs when flight planning seems far less useful - and the heavy emphasis it gets in IFR training seems kinda quaint.  By contrast, I learned very little about MVAs, which would be much more relevant to flight planning and in flight decision making if we could just visualize the data better.  And companies like Foreflight are much more likely to get that done for us than stodgy federal bureaucracies on their own.

Edited October 19, 2021 by DXB

[carusoam]

The power of MS is incredible…

Some great discussion…

Great ideas shared…

Fresh ideas arose…

And one MSer communicated those ideas directly to ForeFlight…

Great MSers have been able to contact outside resources and get really interesting responses…. And share them back here…

Way to go Gents!

Today’s Great MSer award goes to Rich for making that FF contact!

You all deserve the Awesome MSer award… Starting with Dev for bringing this discussion to light…

Extra Thanks to Midlife… my go to guy when I have a rules and regulations question…  especially with the when did that rule change? questions…

Best regards,

-a-

[Ragsf15e]

18 minutes ago, DXB said:

Thanks for input everyone! Several good discussion points here.  It does seem like detailed graphical access to MVAs would be a big advancement.  In an era when navigation is dominated by WAAS GPS, thinking about MEAs when flight planning seems far less useful - and the heavy emphasis it gets in IFR training seems kinda quaint.  By contrast, I learned very little about MVAs, which would be much more relevant to flight planning and in flight decision making if we could just visualize the data better.  And companies like Foreflight are much more likely to get that done for us than stodgy federal bureaucracies on their own.

The problem with using them, even in a local area, is that they are seemingly random shapes of airspace and there’s lots of them with different altitudes in them all.  It’s not like you’re in one area for a long time during cruise, but that might just be out here in the west where there’s terrain.

[DXB]

Just now, Ragsf15e said:

The problem with using them, even in a local area, is that they are seemingly random shapes of airspace and there’s lots of them with different altitudes in them all.  It’s not like you’re in one area for a long time during cruise, but that might just be out here in the west where there’s terrain.

I suppose a summary showing the highest MVA over a broad area, kinda like a minimum elevation figure on a VFR chart, would still be useful for flight planning and avoiding en route surprises.

@Bartman also made an interesting point I think about using the Remarks section.  In this situation, I might have filed a flight plan just using airways with an MEA acceptable to me and explain why I did that in the Remarks.  I wonder if that would have helped save a lot of stress.  

[Bartman]

9 hours ago, DXB said:

 

In this situation, I might have filed a flight plan just using airways with an MEA acceptable to me and explain why I did that in the Remarks.  I wonder if that would have helped save a lot of stress.  

Yes that is what I was trying to say and you articulated it much better than I did. It looks like the controller wanted you on T705 or close to it, and in addition to the higher altitude requirements there are no airports and few options along that route for quite some distance. Hindsight is 20/20 but by filing V487 to a certain point such as CAM and then as desired may have worked in your favor. I have filed like that to avoid summertime convective activity but didn’t put it in the Remarks section because it was obvious I was avoiding what is on radar for everyone to see.
 

In winter and with icing it’s not obvious why we filed a particular route by looking solely at the radar. I have never done it, but adding something about the route requested might be of benefit. I will remember this thread and thank you for posting it. 

[midlifeflyer]

17 hours ago, philip_g said:

The mva is often less than the mea

That's pretty much the reason to have the information available for planning. "How low can I really go" helps with weather planning, especially during icing season.

[philip_g]

44 minutes ago, midlifeflyer said:

That's pretty much the reason to have the information available for planning. "How low can I really go" helps with weather planning, especially during icing season.

The mva is, as others have said, very patchy. It would not be very useful for planning. Not to mention as I’ve said, centers don’t have mva charts so the coverage is fairly limited 

[midlifeflyer]

1 hour ago, philip_g said:

The mva is, as others have said, very patchy. It would not be very useful for planning. Not to mention as I’ve said, centers don’t have mva charts so the coverage is fairly limited 

Maybe useful where you have them and they are understandable. Not where they are not.. 

[philip_g]

2 minutes ago, midlifeflyer said:

Maybe useful where you have them and they are understandable. Not where they are not.. 

spoken like someone that has never seen a MIA or MVA chart. If only there were someone with that information.  You could, you know, just key up and explain the situation and ask what the MIA/MVA is in your area....

 

By the way, the rule referenced above. I was too lazy to try and copy/paste it on my phone

7110.65z s 4.5.6

Except as provided in subparagraphs a and b below, assign altitudes at or above the MEA for the route segment being flown. When a lower MEA for subsequent segments of the route is applicable, issue the lower MEA only after the aircraft is over or past the Fix/NAVAID beyond which the lower MEA applies unless a crossing restriction at or above the higher MEA is issued.

1. An aircraft may be cleared below the MEA but not below the MOCA for the route segment being flown if the altitude assigned is at least 300 feet above the floor of controlled airspace and one of the following conditions are met:

NOTE-

Controllers must be aware that in the event of radio communications or GNSS failure, a pilot will climb to the MEA for the route segment being flown.

1. For aircraft using VOR, VORTAC or TACAN for navigation, this applies only within 22 miles of that NAVAID.
2. When radar procedures are used, the following actions are taken:

1. In the absence of a published MOCA, assign altitudes at or above the MVA or MIA along the route of flight, and
2. Lost communications instructions are issued.

1. The aircraft is GNSS equipped.

1. An aircraft may be cleared to operate on jet routes below the MEA (but not below the prescribed minimum altitude for IFR operations) or above the maximum authorized altitude if, in either case, radar service is provided.

Edited October 19, 2021 by philip_g

[DXB]

3 hours ago, philip_g said:

spoken like someone that has never seen a MIA or MVA chart. If only there were someone with that information.  You could, you know, just key up and explain the situation and ask what the MIA/MVA is in your area....

 

By the way, the rule referenced above. I was too lazy to try and copy/paste it on my phone

7110.65z s 4.5.6

Except as provided in subparagraphs a and b below, assign altitudes at or above the MEA for the route segment being flown. When a lower MEA for subsequent segments of the route is applicable, issue the lower MEA only after the aircraft is over or past the Fix/NAVAID beyond which the lower MEA applies unless a crossing restriction at or above the higher MEA is issued.

1. An aircraft may be cleared below the MEA but not below the MOCA for the route segment being flown if the altitude assigned is at least 300 feet above the floor of controlled airspace and one of the following conditions are met:

NOTE-

Controllers must be aware that in the event of radio communications or GNSS failure, a pilot will climb to the MEA for the route segment being flown.

1. For aircraft using VOR, VORTAC or TACAN for navigation, this applies only within 22 miles of that NAVAID.
2. When radar procedures are used, the following actions are taken:

1. In the absence of a published MOCA, assign altitudes at or above the MVA or MIA along the route of flight, and
2. Lost communications instructions are issued.

1. The aircraft is GNSS equipped.

1. An aircraft may be cleared to operate on jet routes below the MEA (but not below the prescribed minimum altitude for IFR operations) or above the maximum authorized altitude if, in either case, radar service is provided.

I found MVA charts to be inscrutable when I did recently try to look at them - I doubt there are many pilots who know how to extract useful info from them when planning a flight. And I'm not sure I even knew about MIA, which seems like a similar or distinct concept - perhaps the more useful one in non terminal areas?  In regard to icing risk, all I want to know is (1) the highest a controller might be forced to send me on my filed or assigned route (2) how to plan and effectively obtain a route that keeps me below at or below a safe altitude if feasible.  I clearly got it wrong the other day, and it seems like several other folks are unclear on that definitions, concepts, and resources that are relevant to these goals as well.  If you are ATC, your guidance might prove very helpful here. 

Edited October 20, 2021 by DXB

[carusoam]

6 hours ago, philip_g said:

spoken like someone that has never seen a MIA or MVA chart.

Statements like this make me want to hang out with you….

We could sip tea… and discuss hair styles….  

 

Try to be nice or at least cordial to the other MSers…

When you annoy them enough… they don’t tend to come back…

If you need a list of awesome MSers that aren’t hanging around here any longer, or not very much… because of the unfriendliness that is here… I can give you the list.

The person you called out happens to be quite knowledgable on the subject… so what you pointed out is probably the way he types…   

Then again, what if he hasn’t seen an MIA or MVA chart?   Do we blast everybody who is not as skilled…?

So… if we have to be perfect typers to not get blasted with mean remarks… it’s going to get lonely hanging out and discussing hair styles…

Keep MS clean!

MS is on the internet… but it is not the internet….

Best regards,

-a-

[midlifeflyer]

16 hours ago, philip_g said:

spoken like someone that has never seen a MIA or MVA chart.

Damn! And people tell me I'm argumentative... 

10 hours ago, carusoam said:

When you annoy them enough… they don’t tend to come back…

Nah. You just learn who is not worth bothering with.

 

Edited October 20, 2021 by midlifeflyer

[midlifeflyer]

14 hours ago, DXB said:

MIA, which seems like a similar or distinct concept - perhaps the more useful one in non terminal areas? 

A little bit of both. Basically, the MIA, the "minimum IFR altitude" –  is the lowest IFR altitude ATC may assign in a specific airspace. It could be a MOCA, an MEA, an MSA, an MVA, a transition altitude, or a missed approach altitude. Like MVA's, the best way to learn an MIA in the air is from ATC - "How low can you give me?" Like other "unpublished" (just meaning they are not part of the usual group of charts and airport information pilots use), any usefulness they have for planning purposes is questionable. I personally tend to lean toward "not," although people I know and respect think otherwise.

Pretty good article (not mine) on Altitude Limitations in IFR Magazine.

Edited October 20, 2021 by midlifeflyer

[EricJ]

2 hours ago, midlifeflyer said:

Nah. You just learn who is not worth bothering with.

Yes, when somebody's posts just consistently make everyone dumber you just stop reading them.   Unfortunately there are some here like that.

[Ibra]

On 10/19/2021 at 8:16 PM, midlifeflyer said:

That's pretty much the reason to have the information available for planning. "How low can I really go" helps with weather planning, especially during icing season.

That is an interesting question but brief pack will be hundreds of pages  for off-airways, don’t Garmin navigators give you MESA (+/-5nm TO next WPT) and MSA (max MFF for active route), isn’t that the lowest one can go when it’s life & death question? or it’s not very reliable? ignoring loss of ATC comms & radar 
https://www.manualslib.com/manual/253279/Garmin-Apollo-Gx55.html?page=14

MVA in terminal areas can be very low and misleading for en-route, down to +/-1nm resolution: ATC can even circle a tall obstacle with 1nm radius and raise MVA inside and let you fly around it, but it’s hard to build en-route altitude out of these without overlay and they don’t give +/-5nm resolution for en-route? theoretically, the MVA terminal charts can be flown on with GPS set to +/-0.3nm but I expect the workload to be high: mix of mountain flying & approach flying for 2h 

If one sticks to en-route VOR airways, radar MVA is usually higher than procedural MEA on these but worst case one can go down to their published MOCA when it’s life & death 

There are other caveats on losing IFR clearance, legality, lost coms & radar procedures, penetration of other sectors but I am not familiar how things works in US, I am only looking at this from a simpler angle: “IFR in IMC without collecting (soft) ice and without hitting (hard) terrain” and probably not talking to anyone and no 7600 blip…

The only reassuring thing, even without ATC when com & radar is lost, no other traffic is supposed to fly in that “no mans land” in IMC, it’s empty levels, not a single VFR or IFR flies there 

Edited October 20, 2021 by Ibra

[midlifeflyer]

17 hours ago, Ibra said:

That is an interesting question but brief pack will be hundreds of pages  for off-airways, don’t Garmin navigators give you MESA (+/-5nm TO next WPT) and MSA (max MFF for active route), isn’t that the lowest one can go when it’s life & death question?

I'm not familiar with the term MESA. In the US, the MSA ("minimum safe altitude," not "minimum sector altitude")is strictly an emergency altitude generally significantly higher than the minimum altitude for a sector. In modern days, I think the MSA is primarily for a loss of all navigation and communication equipment. Even then it's only practical use is to stay high enough until reaching visual conditions since you gotta get down sometime. If you do have nav capability – even emergency nav capability like an EFB –  it will be rare to need it. In the US we are so filled with airways with MEAs and MOCAs a more practical choice for an emergency would be to get on a nearby airway, take it to the nearest approach transition, and come on down. I am doubtful about how much MVA information would make a difference in that scenario, although I know others who feel it would. 

But I don't think that's what we are (or at least I am)  talking about when talking about access to MVA information. The original question was about icing and the ability for ATC to provide an IFR altitude lower that those published, whether MEA, MOCA, OROCA or MSA as a way to avoid or escape icing. I'm kind of on the fence.

If it comes to pass, I doubt it will be "hundreds of pages." Far more likely to be a data package. Long tap an area on our EFB and along with all the other information about the area (probably based on tens of thousands of pages , you would get an MVA.

Edited October 21, 2021 by midlifeflyer

[Ibra]

2 hours ago, midlifeflyer said:

In the US we are so filled with airways with MEAs and MOCAs a more practical choice for an emergency would be to get on a nearby airway, take it to the nearest approach transition, and come on down. I am doubtful about how much MVA information would make a difference in that scenario, although I know others who feel it would

On MVA, I am thinking an iced radio antenna while flying on tactical tight radar vectoring would be interesting 

From looking at Airways charts, MOCA is very refined for emergency use, so just join it and go down along it, this is way more convenient in US but the question of how low one can go usually comes when going "off-route" on own navigation or directs rather than controller radars or published routes

On GPS own navigation or directs, these are the numbers Garmin IFR avionics produce in top of MFD, they may not tie out with min safe/sector/route/radar altitudes depending on the leg length/size and the actual definition (they do not match with Jepps chart for mountain terrain 3000ft vs 5000ft, also they may not fit very well with ATC systems or MIAs), another question how much one can bet their life on these? 

https://www.manualslib.com/manual/253279/Garmin-Apollo-Gx55.html?page=14

Minimum Safe Altitude (MSA)

MSA is calculated by taking the Maximum Elevation Figure (MEF) from the sectional

chart grid that corresponds to your current position. In areas below 3,000 feet, 1,000 feet

is added. In areas above 3,000 feet, 2,000 feet is added. In the example below, the current

aircraft would be considered to be at 7,000 feet. If you are within 5 nm of another grid

with a higher MEF, the higher MEF will be used. The MEF on the sectional chart is

derived by taking the altitude of the highest obstruction within the grid, rounded up to the

next 100 feet, and adding 300 feet. For example, if the highest obstruction is 4,728 feet,

the MEF would show as 5,100 feet.

Minimum En Route Safe Altitude (MESA)

Minimum En Route Safe Altitude is the highest MSA for every point between the aircraft

present position and the "TO" waypoint with a 5 nm buffer around the course. The value

will be replaced with dashes if there is no valid GPS position, the TO waypoint is blank,

or the current position is outside of the database coverage area. In the example shown

above, the MESA for the present position of the aircraft would be 16,800 ft. The

mountainous terrain would add a 2,000 ft. buffer to the 14,800 ft. Maximum Elevation

figure indicated from the sectional chart

 

Edited October 21, 2021 by Ibra

[Sixstring2k]

ForeFlight did an update today and i saw this, was this what you guys are referring too?

Edited October 27, 2021 by Sixstring2k

[bradp]

In addition to MVAs, radar controller have access to video map overlays of emergency vectoring altitudes, which as I understand, disperse with the formalities of obstruction clearance buffers.  
 

for MVA maps, ask nicely to the retired airline guy on BT who worked with TERPS - he’ll  often post VMO MVAs on a Google map. 

[RobertGary1]

MVAs also vary by time of day and day of thr week. Out west we have part time facilities that revert to center which has less coverage. So trying to predict mva or frequencies is not easy. A lot of military approach control facilities are not full time. 

[ZMERC]

1. When you're cleared on a route, is the final altitude assigned supposed to work for all MVAs along the route?  I'd assumed that was the case...but that's not how it played out yesterday.

no. MVAs don't apply to routings, UNLESS it's a radar vector or a direct point to point clearance, like in BVT direct PHL.  They are established specifically for ATC to use.  There are some exceptions to everything, I realize, but in most cases a controller won't give you a direct routing BELOW an MVA.  This is because there are several reasons the MVA is established, could be obstructions, terrain, radar or radio coverage, etc.

2. Is there a good resource that gives you a global picture of MVAs along your route?  The FAA website MVA charts by sector are patchy and hard to line up to the real geography and MEAs on the sectionals.

again, no.  MVAs sometimes change and you can refer to #1 as to why it doesn't really matter if they're published in a global picture.  my caveat to this is, if there is, it's not available to controllers. 

3. During flight planning, I've generally just looked at the MEAs in an area to figure what minimum altitudes I can expect to get. Is there a better approach here?  I now realize that MVAs can sometimes be higher than MEAs.   BTW, for the segment in the scenario above, I was given direct point to point, not on an airway.

Your method is a good approach.  however, you may get changes, like in this case.  If you can't or don't want to be assigned a higher altitude, then file airways and stay above MEAs.  Also, you can put in remarks section of your flight plan that you request to stay below xxx feet.  That would let ATC know you have a restriction.

4. With winter coming, any other useful flight planning trips for us non-FIKI equipped folks?  In the northeast, late October to late April ends up mostly being a VFR season for me, which is very limiting.

like in #3, file airways and let ATC know early you'd like to stay on course because you don't want to be above the freezing level in clouds.

retired ATC (Center).  My views are my opinion, not established FAA regulations.

[DXB]

 

 

On 10/29/2021 at 1:33 PM, ZMERC said:

If you can't or don't want to be assigned a higher altitude, then file airways and stay above MEAs.  Also, you can put in remarks section of your flight plan that you request to stay below xxx feet.  

 Let ATC know early you'd like to stay on course because you don't want to be above the freezing level in clouds.

retired ATC (Center).  My views are my opinion, not established FAA regulations.

Thanks!!   I think these are the main takeaways that were emerging from this thread, and having them reaffirmed by someone with ATC background is super helpful.