AIRMET Zulu: regulatory or advisory?

[aloft]

So now that it's Winter, AIRMET Zulu promises to be a regular feature of many pre-flight weather briefings. My question is, what is their regulatory significance in terms of flying with an area for which an AIRMET Zulu has been issued? Is it regulatory in nature, meaning one may not fly within the area described by the AIRMET in an aircraft not certified for flight in icing conditions; or is it simply advisory--as in, you'd do well to keep on the lookout?

 

[bigs]

Not regulatory as in prohibited airspace, but certainly critical information to have as you're doing a preflight weather briefing and could definitely affect go/no-go or route or altitude of flight.

 

[tgrayson]

Is it regulatory in nature, meaning one may not fly within the area described by the AIRMET in an aircraft not certified for flight in icing conditions; or is it simply advisory--as in, you'd do well to keep on the lookout?

The case law hasn't been very permissive about this issue. Forecast icing has been treated as known icing. If you flew at or above the forecast freezing level and encountered problems due to icing, you'd probably get hit with violating the "known icing" prohibition.

I believe the FAA has recently updated its guidance on this, but I haven't read it. Midlifeflyer probably has the references.

 

[Tommay85]

I think you'd be pretty nuts to even go into any kind of visible moisture on purpose with an airmet for icing issued anyway. I'm pretty sure anyway you slice it, you're in trouble if you encounter ice and have problems in an area with an airmet z issued.

I look at them kind of like the AIM. The AIM isn't regulatory, but if you go against the information in it and mess up, you get the lovely "careless and reckless operation" catch all violation.

 

[MidlifeFlyer]

Your definitions of regulatory and non-regulatory don't make sense to me in this context, in part because there really isn't a regulation that directly prohiits flight into known icing to begin with - it's actually covered by the FAR that deals with operation contrary to aircaraft limitations.

So let's put it this way. If the net result of your aircraft limitations is that flight into "known icing" is prohibited, if there was an airmet for icing and you encounter icing in flight under circumstances that the FAA decides to initiate a certificate action, the icing was definitely "known."

You can decide whether that fits your definition of "regulatory" or not.