Atc & mea

PGT

Well-Known Member
The other day I was told to descend to an altitude which was 1,000 below MEA. This is in the middle of no where so not close to any controlled airspace.

I don't think I was within 22mi for the MOCA.

Can ATC legally descend me below MEA and should I say something?
 

pwttogfk

Well-Known Member
ATC has the MVA, which is the minimum vectoring altitude for the area. It can be below the MEA. Yes, you can descend from MEA if given a clearance.
 

tgrayson

New Member
Can ATC legally descend me below MEA and should I say something?
Minimum IFR altitudes are governed by 14 CFR 91.177. If you're on an airway or other published route, MEA/MOCA are rock bottom altitudes. The regulation contains no provision for ATC to give you lower. In fact, the regulation contains no provision for ATC derived altitudes at all.

However, when no MEA/MOCA applies, ATC can assign altitudes that comply with this paragraph:
(2) If no applicable minimum altitude is prescribed in parts 95 and 97 of this chapter, then--
(i) In the case of operations over an area designated as a
mountainous area in part 95 of this chapter, an altitude of 2,000 feet above the highest obstacle within a horizontal distance of 4 nautical miles from the course to be flown; or
(ii) In any other case, an altitude of 1,000 feet above the highest obstacle within a horizontal distance of 4 nautical miles from the course to be flown.
These altitudes are charted for ATC's use and are referred to as "MVA's" when used by approach controls and MIA's when used by Center, and, in theory, provide you with the terrain clearance required by 91.177. You generally don't have any way to verify that.

So, if you were on an airway under your own navigation, then the altitude assigned by ATC would not be legal. If you were off airway, then it probably was (but they do make mistakes).

Since you used the acronym "MEA", that implies you were on an airway, but some people use the term to describe the non-regulator altitudes of MORA or OROCA.
 

tgrayson

New Member
I was on an airway, they told me to descend because of traffic.
You were IFR?

Here's the guidance from the ATC Handbook:

4−5−6. MINIMUM EN ROUTE ALTITUDES
Except as provided in subparas 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.
a. 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 failure, a pilot will climb to the MEA for the route segment being flown.
1. Nonradar procedures are used only within 22 miles of a VOR, VORTAC, or TACAN.
2. Radar procedures are used only when an operational advantage is realized and the following actions are taken:
(a) Radar navigational guidance is provided until the aircraft is within 22 miles of the NAVAID, and
(b) Lost communications instructions are issued.
 

PGT

Well-Known Member
You were IFR?

Here's the guidance from the ATC Handbook:

4−5−6. MINIMUM EN ROUTE ALTITUDES
Except as provided in subparas 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.
a. 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 failure, a pilot will climb to the MEA for the route segment being flown.
1. Nonradar procedures are used only within 22 miles of a VOR, VORTAC, or TACAN.
2. Radar procedures are used only when an operational advantage is realized and the following actions are taken:
(a) Radar navigational guidance is provided until the aircraft is within 22 miles of the NAVAID, and
(b) Lost communications instructions are issued.
yes I was IFR.

Not sure what happened, if it happens again I'll verify with the controller.
 

tgrayson

New Member
Not sure what happened, if it happens again I'll verify with the controller.
If you're unsure of the terrain, then it's wise. Odds are, however, that the altitude was exactly what ATC intended. They seem to generally feel they have the authority to give you MVA/MIA whenever it serves their purposes, even if it doesn't enable you to comply with 91.177 and isn't exactly inline with the .65, which suggests that they need to provide navigation if this happens. (Even that's a bit iffy with regard to 91.177).

You might have an interesting conversation if you called Center (I assume it was Center) on the telephone and discussed it politely with a watch supervisor. Ask where comes the authority to be assigned an altitude below MEA/MOCA on an airway when you are not receiving navigation assistance.
 

Juliet Lima

New Member
definitely.

we have an airway, V105 i believe, between OAL and FMG. it has a 12,500 MEA. but the MIA in that area is 11,000. so as long as we are able to radar monitor u, we can descend u below the MEA even though u are on the airway. the only other stipulation is that u have a way of getting ahold of us in the case of NORDO. so techinically lost comm procedures should be put in place. we/i never do it since i know we'll keep u on comms.
 

tgrayson

New Member
but the MIA in that area is 11,000. so as long as we are able to radar monitor u, we can descend u below the MEA even though u are on the airway.
There is a distinction between what you can give us and what we can accept. FAR 91.177 makes no allowance for what you suggest. And the .65 says you must provide the pilot with "Radar navigational guidance", which strikes me as being different from "monitoring".
 

Alpha Lima

New Member
Radar navigational guidance to me makes it sound similar to holding pattern surveillance, keep an eye on you and assist in returning you to the correct area if you go off course. Or simply using my radar to give you a heading to keep you on the airway if you cant receive the NAVAIDs.
 

tgrayson

New Member
Or simply using my radar to give you a heading to keep you on the airway if you cant receive the NAVAIDs.
That's how I view it. If you give me a heading, I'm being vectored and so, arguably, I'm no longer on the airway, thus escaping the MEA requirement of 91.177.
 

Juliet Lima

New Member
And the .65 says you must provide the pilot with "Radar navigational guidance", which strikes me as being different from "monitoring".
"Radar navigational guidance" is different from "monitoring". Monitoring just means we watch your annoying blip go across our screen. "Radar navigational guidance" is when we actually give u a heading. Usually cuz your lame a$$ equipment can't do what you actually filed you were able to do. i.e. /A or /W. so where in the .65 does it clarify the difference between "radar navigational guidance" and "monitoring"...even though i agree that it is different.

anyway, a descent is not a suggestion...it's an ATC clearance. you have to descend or make it known that your are rejecting an ATC clearance when you don't want to do what we tell u to. regardless of what you say here:
There is a distinction between what you can give us and what we can accept. FAR 91.177 makes no allowance for what you suggest
because we could get into a pilot deviation situation if u reject an ATC clearance because your high horse can't descend for ego reasons. in that case...cancel IFR and go on your happy way VFR without traffic advisories. heck u have TCAS don't u :laff:
 

Juliet Lima

New Member
alright the "political correctness" made me write this:

pilots ALWAYS have the prerogative to reject an ATC clearance because u either can't do it or because of safety of flight. if we give u a descent that u think puts u in danger because of terrain then by all means reject it. but if we are later justified in our actions, you better have a damn good reason why u rejected the descent. alright, that didn't come out as PC as i expected.
 

Bernoulli Fan

Controller
if u reject an ATC clearance because your high horse can't descend for ego reasons. in that case...cancel IFR and go on your happy way VFR without traffic advisories. heck u have TCAS don't u :laff:
Are we up here because you're down there? Or are you down there because we're up here?
 

Maurus

The Great Gazoo
"Radar navigational guidance" is different from "monitoring". Monitoring just means we watch your annoying blip go across our screen. "Radar navigational guidance" is when we actually give u a heading. Usually cuz your lame a$$ equipment can't do what you actually filed you were able to do. i.e. /A or /W. so where in the .65 does it clarify the difference between "radar navigational guidance" and "monitoring"...even though i agree that it is different.

anyway, a descent is not a suggestion...it's an ATC clearance. you have to descend or make it known that your are rejecting an ATC clearance when you don't want to do what we tell u to. regardless of what you say here:
because we could get into a pilot deviation situation if u reject an ATC clearance because your high horse can't descend for ego reasons. in that case...cancel IFR and go on your happy way VFR without traffic advisories. heck u have TCAS don't u :laff:
A little agressive arent we?

Here are some definitions from the Pilot/Controller gloassary (FAA definitions).

Radar Monitoring- The radar flight-following of aircraft, whose primary navigation is being performed by the pilot, to observe and note deviations from its authorized flight path, airway, or route. When being applied specifically to radar monitoring of instrument approaches; i.e., with precision approach radar (PAR) or radar monitoring of simultaneous ILS/MLS approaches, it includes advice and instructions whenever an aircraft nears or exceeds the prescribed PAR safety limit or simultaneous ILS/MLS no transgression zone.

Radar Navigational Guidance- Vectoring aircraft to provide course guidance

If you drop a pilot below the MEA (which means the pilot is not guaranteed navigational guidence) you must give them a vector. No way to get around that. Pilots should not accept a clearence below the MEA unless they get a vector to go with it, or there is a moca and the pilot is within 22 NM of the navaid being used.

Pilots can not accept any clearence the will break a reg and should approprietly respond with the word "Unable"
 

Sunburn

Well-Known Member
The other day I was told to descend to an altitude which was 1,000 below MEA. This is in the middle of no where so not close to any controlled airspace.

I don't think I was within 22mi for the MOCA.

Can ATC legally descend me below MEA and should I say something?

Um..... I have a simple question. If you where in uncontrolled (Class G airspace) why where you talking to ATC and taking clearances anyways?



I know I know, I'm a "wiseguy"

Remember class E is controlled airspace, which mean unless the controller has a brain dump, pilots shall comply with ATC clearances unless in the pilot's best judgment doing so will endanger his/herself or his/her passengers [the formally mentioned brain dump] (I.E. emergence deviation).
 
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