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

[DXB]

While planning my trip back to Philly from Burlington VT yesterday, I noticed a freezing level and ice forecast starting at 7000ft, with nothing below that.  There were also patchy low clouds down to ~1500ft in the Hudson Valley, so it seems best to go IFR.  I filed a route that I hope will take me down the Hudson Valley at 4000ft to keep me well away from any ice.  Instead I got a route over the Adirondacks at 6000 ft. I assumed 6000 must also be the highest MVA for my cleared route since it's the MEA for a segment over the mountains.  6000 was closer to the freezing level and forecast ice than I wanted, but I thought "let's try, I can always escape east into the Hudson valley if need be."  At 6000, OAT was about 2-3C, and there was no ice while I'm in and out of IMC in patchy light precip - I relax and think everything is fine at this point. Then the Burlington controller tells me to climb to 7000 for her MVA on that part of my route and specifically tells me (unsolicited) that 7000 should still keep me clear of ice reported down to 8000.  I foolishly comply, and during the climb get handed to Boston Center.  At 7000 I start to pick up rime, and there appear to be multiple scattered-broken cloud layers above me, so trying to climb out seems like a bad idea.  I tell the Boston controller about it and ask when I can return to 6000 and he says not any time soon on this route .  I then "request immediate descent, any heading" with a bit of deliberate tension in my voice - I've practiced this in my head but never used it. It works - I'm turned hard to the east and allowed to descend into the valley.  By that point I have moderate mixed ice on my wings, which rapidly sheds as I descend down to 5000.  I wish I'd taken a picture of it, but I had other priorities at the moment - definitely my worst icing encounter. If I hadn't been given the hard turn and descent, I would have declared an emergency and just done it.

Questions:

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.

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.

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.

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.

 

 

Edited October 18, 2021 by DXB

[carusoam]

Interesting IFR and IMC experience question…

Lets invite @midlifeflyer to the conversation…

Best regards,

-a-

[Ragsf15e]

16 minutes ago, DXB said:

While planning my trip back to Philly from Burlington VT yesterday, I noticed a freezing level and ice forecast starting at 7000ft, with nothing below that.  There were also patchy low clouds down to ~1500ft in the Hudson Valley.  I filed a route that I hope will take me down the Hudson Valley at 4000ft to keep me well away from any ice.  Instead I got a route over the Adirondacks at 6000 ft. I assumed 6000 must also be the highest MVA for my cleared route since it's the MEA for a segment over the mountains.  6000 was closer to the freezing level and forecast ice than I wanted, but I thought "let's try, I can always escape east into the Hudson valley if need be."  At 6000, OAT was about 2-3C, and there was no ice while I'm in and out of IMC in patchy light precip - I relax and think everything is fine at this point. Then the Burlington controller tells me to climb to 7000 for her MVA on that part of my route and specifically tells me (unsolicited) that 7000 should still keep me clear of ice reported down to 8000.  I foolishly comply, and during the climb get handed to Boston Center.  At 7000 I immediately start to pick up rime, and there appear to be multiple scattered-broken cloud layers above me, so trying to climb out seems like a bad idea.  I tell the Boston controller and when I can return to 6000 and he says not any time soon on this route .  I then "request immediate descent, any heading" with a bit of deliberate tension in my voice - I've practiced this in my head but never used it. It works - I'm am turned hard to the east and allowed to descend into the valley.  By that point I have moderate mixed ice on my wings, which rapidly sheds as I descend down to 5000.  I wish I'd taken a picture of it, but I had other priorities at the moment - definitely my worst icing encounter. If I hadn't been given the hard turn and descent, I would have declared an emergency and just done it.

Questions:

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.

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.

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.

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.

 

 

 

MVAs are like closely held secrets for some reason.  Unless I’m in my local class c and know exactly what they are and how the controllers use them, I wouldn’t plan for them.

If you want the lowest altitude, you gotta stick to published/charted routes.  So in your situation, file a planned V route through the valley at say 5 or 6k.  If they “help you out” and give you direct or some other routing, say “unable”, “I need to stay on Vxxx to stay below ice.”  Then they know what you’re doing.  Otherwise, they’re trying to help you out.

V routes are surveyed for (these numbers are not exact, just example) like 5-10nm off centerline and 2000’ above mountainous terrain or 1k above flat.  The MRAs on Victor routes are “always” (someone probably find one not) lower than the MEA or OROCA published in 30nm squares.

I have had a similar experience where i filed between two VORs that define a victor route.  I was given 9,000’.  I wanted the route MEA of 7,000’.  Controller says, my MVA is 9,000.  I say, sorry, request new clearance on Vxxx (which I’m already on) and he says, oh, hold on… cleared Vxxx at 7,000’.  There’s definitely a disconnect there and they don’t have all possible MEAs MVAs available in front of them at all times.

Edited October 18, 2021 by Ragsf15e

[Ragsf15e]

21 minutes ago, DXB said:

While planning my trip back to Philly from Burlington VT yesterday, I noticed a freezing level and ice forecast starting at 7000ft, with nothing below that.  There were also patchy low clouds down to ~1500ft in the Hudson Valley.  I filed a route that I hope will take me down the Hudson Valley at 4000ft to keep me well away from any ice.  Instead I got a route over the Adirondacks at 6000 ft. I assumed 6000 must also be the highest MVA for my cleared route since it's the MEA for a segment over the mountains.  6000 was closer to the freezing level and forecast ice than I wanted, but I thought "let's try, I can always escape east into the Hudson valley if need be."  At 6000, OAT was about 2-3C, and there was no ice while I'm in and out of IMC in patchy light precip - I relax and think everything is fine at this point. Then the Burlington controller tells me to climb to 7000 for her MVA on that part of my route and specifically tells me (unsolicited) that 7000 should still keep me clear of ice reported down to 8000.  I foolishly comply, and during the climb get handed to Boston Center.  At 7000 I immediately start to pick up rime, and there appear to be multiple scattered-broken cloud layers above me, so trying to climb out seems like a bad idea.  I tell the Boston controller and when I can return to 6000 and he says not any time soon on this route .  I then "request immediate descent, any heading" with a bit of deliberate tension in my voice - I've practiced this in my head but never used it. It works - I'm am turned hard to the east and allowed to descend into the valley.  By that point I have moderate mixed ice on my wings, which rapidly sheds as I descend down to 5000.  I wish I'd taken a picture of it, but I had other priorities at the moment - definitely my worst icing encounter. If I hadn't been given the hard turn and descent, I would have declared an emergency and just done it.

Questions:

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.

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.

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.

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.

 

 

 

Also, good job speaking up, and good learning!

[Bartman]

Good on you for quickly finding a solution, time was definitely not on your side while accumulating ice. 
 

I have wondered about this very scenario. I’ve been given routing deviations that I have replied unable due to convective stuff the controllers can’t see on radar, but what about declining or a request to modify the clearance itself ?  I have never had a reason to decline a clearance but a situation like this might be the one. Also, what about adding something in the remarks section ?  I’ve never done that but this might be a good time to consider it. 

[N201MKTurbo]

Good job dealing with the ice.

There have been some posts on here that have said you are a bad pilot if you get into ice. I have flown enough to know that that simply isn't true. The only way to stay out of the ice is to stay out of the clouds. I think you did everything correct, ice happens, reroutes happen, you just have to deal with it.

[N201MKTurbo]

BTW, I hope you got a PIREP in so the controller won't be saying there is no ice at 7000.

[Ragsf15e]

21 minutes ago, N201MKTurbo said:

Good job dealing with the ice.

There have been some posts on here that have said you are a bad pilot if you get into ice. I have flown enough to know that that simply isn't true. The only way to stay out of the ice is to stay out of the clouds. I think you did everything correct, ice happens, reroutes happen, you just have to deal with it.

Also, you (the OP) had a plan prior, knew where there was likely to be ice, and knew where to go to get lower.  Nothing wrong with that.

[midlifeflyer]

A Victor airway MEA guarantees obstruction clearance and a usable navigation signal. It does not guarantee a reliable communication signal. An MVA on the other hand, requires radar contact and a reliable communication signal. So I can definitely see a MVA being higher than an MEA, particularly on certain routes in mountainous areas, although it's not common. So, perhaps the answer to why is as simple as concerns over radar coverage or line-of-sight communication capability.

What to do about it if concerned about going higher because of say, the icing potential? I'd tell ATC I was unable to climb because of potential icing, tell them I needed to remain at the MEA. If the reason is lack of radar or com coverage lower down, and work out a recontract plan with them once past the terrain causing a problem.

There's a section of V83 somewhere between PUB and FTI where Albuquerque Center would lose com. They tell you about it in advance..

[thinwing]

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...

[ilovecornfields]

26 minutes ago, midlifeflyer said:

A Victor airway MEA guarantees obstruction clearance and a usable navigation signal. It does not guarantee a reliable communication signal. An MVA on the other hand, requires radar contact and a reliable communication signal. So I can definitely see a MVA being higher than an MEA, particularly on certain routes in mountainous areas, although it's not common. So, perhaps the answer to why is as simple as concerns over radar coverage or line-of-sight communication capability.

What to do about it if concerned about going higher because of say, the icing potential? I'd tell ATC I was unable to climb because of potential icing, tell them I needed to remain at the MEA. If the reason is lack of radar or com coverage lower down, and work out a recontract plan with them once past the terrain causing a problem.

There's a section of V83 somewhere between PUB and FTI where Albuquerque Center would lose com. They tell you about it in advance..

Is that true? I though the MOCA guaranteed obstruction clearance and the MEA guaranteed obstruction clearance and nav signal? My understanding is the MVA are usually defined by chunks of airspace so they’re almost always going to be higher than the MEA because it has to account for all of the terrain in that airspace, not just within the area defined by the airway.

Edit: it looks like I wasn’t entirely right either:

https://www.boldmethod.com/blog/lists/2021/02/you-should-know-these-ten-minimum-ifr-altitudes/

 

Edited October 18, 2021 by ilovecornfields

[N201MKTurbo]

Find your MVAs here:

Now, if you only had a radar screen to overlay them on...

[N201MKTurbo]

Ya know, I've had good luck suggesting features to ForeFlight. It looks like all the data for a comprehensive MVA map is publicly available, just not in a usable fashion. It looks like it would be pretty cluttered in some places. I think I will suggest they add MVA and MIA overlays to their charts.

[kortopates]

39 minutes ago, ilovecornfields said:

Is that true? I though the MOCA guaranteed obstruction clearance and the MEA guaranteed obstruction clearance and nav signal?

Yes, MEA ensures both obstruction clearance (1000' non-mountainious and 2000' in mountainous terrain) and navigation signal reception on the airway.

The MOCA is the same except that Navigation signal is only guaranteed for 22 nm.

But who cares about the 22 nm limitation when RNAV equipped and in fact GPS equipped aircraft can ask for and be cleared at the MOCA altitude for any segment with a defined MOCA, with the two caveats: the assigned altitude must be at least 300' above the floor of controlled airspace and controller has to provide you with lost comm instructions to climb to the MEA if communications or GPS is lost. But out west this can make the difference between flying at a O2 required MEA versus below an O2 required MOCA altitude. 

[kortopates]

57 minutes ago, N201MKTurbo said:

Ya know, I've had good luck suggesting features to ForeFlight. It looks like all the data for a comprehensive MVA map is publicly available, just not in a usable fashion. It looks like it would be pretty cluttered in some places. I think I will suggest they add MVA and MIA overlays to their charts.

Jeppessen used to publish MVA maps for every TRACON here in the US for many years and stopped doing so about a decade or more ago. They still do publish these outside of the US. I recall Jepp saying they stopped because they became to dynamic in the US but that was too long ago to remember.

[N201MKTurbo]

1 minute ago, kortopates said:

Jeppessen used to publish MVA maps for every TRACON here in the US for many years and stopped doing so about a decade or more ago. They still do publish these outside of the US. I recall Jepp saying they stopped because they became to dynamic in the US but that was too long ago to remember.

By dynamic, I assume they mean the FAA changes things to often. It looks like the data is available in XML format in real time. once someone like ForeFlight wrote the software to parse it and display it, it would be no trouble to update it.

Lets hope for the best. 

[midlifeflyer]

2 hours ago, ilovecornfields said:

Is that true? I though the MOCA guaranteed obstruction clearance and the MEA guaranteed obstruction clearance and nav signal?

Isn't that what I said?

[philip_g]

6 hours ago, Ragsf15e said:

MVAs are like closely held secrets for some reason.  Unless I’m in my local class c and know exactly what they are and how the controllers use them, I wouldn’t plan for them.

If you want the lowest altitude, you gotta stick to published/charted routes.  So in your situation, file a planned V route through the valley at say 5 or 6k.  If they “help you out” and give you direct or some other routing, say “unable”, “I need to stay on Vxxx to stay below ice.”  Then they know what you’re doing.  Otherwise, they’re trying to help you out.

V routes are surveyed for (these numbers are not exact, just example) like 5-10nm off centerline and 2000’ above mountainous terrain or 1k above flat.  The MRAs on Victor routes are “always” (someone probably find one not) lower than the MEA or OROCA published in 30nm squares.

I have had a similar experience where i filed between two VORs that define a victor route.  I was given 9,000’.  I wanted the route MEA of 7,000’.  Controller says, my MVA is 9,000.  I say, sorry, request new clearance on Vxxx (which I’m already on) and he says, oh, hold on… cleared Vxxx at 7,000’.  There’s definitely a disconnect there and they don’t have all possible MEAs MVAs available in front of them at all times.

They’re right in the faa website is paste the link but the forum won’t let me for some reason 

Centers use Mia. Approaches use mva

 

 

[philip_g]

2 hours ago, kortopates said:

Yes, MEA ensures both obstruction clearance (1000' non-mountainious and 2000' in mountainous terrain) and navigation signal reception on the airway.

The MOCA is the same except that Navigation signal is only guaranteed for 22 nm.

But who cares about the 22 nm limitation when RNAV equipped and in fact GPS equipped aircraft can ask for and be cleared at the MOCA altitude for any segment with a defined MOCA, with the two caveats: the assigned altitude must be at least 300' above the floor of controlled airspace and controller has to provide you with lost comm instructions to climb to the MEA if communications or GPS is lost. But out west this can make the difference between flying at a O2 required MEA versus below an O2 required MOCA altitude. 

Also in radar…

Edited October 18, 2021 by philip_g

[ilovecornfields]

2 hours ago, midlifeflyer said:

Isn't that what I said?

Yes. I misread it. My apologies.

[RobertGary1]

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 

I won’t go unless the mea on the airway is clear of ice. The mva shouldn’t be less than the mea. 

[Ragsf15e]

1 hour ago, philip_g said:

They’re right in the faa website is paste the link but the forum won’t let me for some reason 

Centers use Mia. Approaches use mva

 

 

Yes, but try finding an enroute resource where you can use them in flight.  Unless you download and map them yourself for your whole route, there isn’t anything.  Needs an overlay on FF as discussed above.

[N201MKTurbo]

20 minutes ago, Ragsf15e said:

Yes, but try finding an enroute resource where you can use them in flight.  Unless you download and map them yourself for your whole route, there isn’t anything.  Needs an overlay on FF as discussed above.

I heard back from ForeFlight. They are considering the feature. There is hope.

[philip_g]

1 hour 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 

I won’t go unless the mea on the airway is clear of ice. The mva shouldn’t be less than the mea. 

The mva is often less than the mea

Edited October 19, 2021 by philip_g

[philip_g]

1 hour ago, Ragsf15e said:

Yes, but try finding an enroute resource where you can use them in flight.  Unless you download and map them yourself for your whole route, there isn’t anything.  Needs an overlay on FF as discussed above.

Forflight problem and not an faa problem. You would think you could import any raster chart you want 

Edited October 19, 2021 by philip_g