What constitutes know icing?

[paulsalem]

Snow?
A pirep with icing?
Forecast Clouds above freezing level?

 

[Weasil]

The FAA's pamphlet on Icing regulations makes it very clear that their intention is to prohibit flight into known icing conditions. They do not mean "known icing" as there is no way to know that icing currently exists for sure. They mean... are the conditions you are about to fly into known icing conditions. If so... don't go.

 

[rubberducky]

Actually I disagree with Weasil. If conditions that are conducive to icing are forecasted, that does not make them "known icing conditions" (as you stated). It becomes known when an aircraft reports the icing. Then unless you're in a known icing approved aircraft you cannot go legally. So if you see a forecast that would probably call for icing in the clouds you could still takeoff in a C172 for example (definitely not wise). But as soon as you reported icing then your buddies at the airport would be stuck in their 172s legally that is...

 

[transpac]

Why the concern about the definition of known icing? FAR 135.227 pertains to known icing, but it only applies to VFR flight. The 135.227 requirement that applies to IFR also throws in forecast icing conditions. Staying out of known icing conditions while VFR shouldn't be much of a challenge.

 

[mar]

A PIREP constitutes known icing, but...

...it's only valid for the time given.

In other words, just because some guy reported icing over ABC VOR at 1300Z at 5000' doesn't mean there's icing at the same position and altitude 10 minutes later.

Grey area? Yes. Use your brains as always.

 

[A Squared]

Why the concern about the definition of known icing?

You're right, the Part 135 regs you qote seem to render the distinction moot, for Part 135 operations. It would seem though that it would still have implications for pilots under Part 91 only flying aircraft which are not certificated for flight into known icing, or known icing conditions, or however the AFM words it

 

[TonyC]

Use your brains as always.

Talk about your GRAY AREAS ! ! !









.

 

[A Squared]

Actually I disagree with Weasil.

Actually, that's a shame, because actually he's right and you are not.

If conditions that are conducive to icing are forecasted, that does not make them "known icing conditions"

Actually, yes it does, in the eyes of the FAA, and the NTSB

So if you see a forecast that would probably call for icing in the clouds you could still takeoff in a C172 for example

Actually, no, you couldn't, not legally.

You might want to read Administrator vs.Groszer http://www.ntsb.gov/O_n_O/docs/aviation/3770.PDF

Short story: there was a Sigmet for Icing, but there were several PIREPS for negative icing pilot departed in airplane not certificated for known icing (Part 91 only). Bottom line, pirep didn't matter, what matters is icing was forcast Certificate suspended.

from Adminstrator vs. Grozer, citing the earlier Administrator Vs Bowen: "Indeed, Bowen holds that the lack of a PIREP forecasting icing in a particular area does not excuse the disregarding of forecast data. We stated that "known" does not mean a near-certainty of icing conditions, only that icing conditions are being reported or forecast."​

If icing is forcast, it is known icing conditions. Period.​

It doesn't matter if there are no PIREPS for ice,​

It doesn't even matter if there are PIREPS for *No ICE"​

If it is forcast, it is known, you stay on the ground.​

 

[Lead Sled]

A Squared nailed it. I've been doing a lot of research lately and it boils down to the fact that if icing is reported OR forecast you need to have the equipment and the "known icing certification" to be legal. I wish it wasn't so, but it is.

Lead SLed

 

[philo beddoe]

Correct me if I am wrong, but I believe that airplanes are certified for "flight in icing conditions" not "flight in known icing conditions".

The term "known icing" applies only to operational regulations, not aircraft certification regulations.



You do not always get the complete picture when you play lawyer with the FARs. What you really need to know is not what a particular regulation says, but what the FAA legal department BELIEVES the regulation says.

Forecast possible icing can be interpreted as known icing for enforcement action purposes.

Also, even though pt 91 does not address pilot operations in icing conditions, remember that it is a violation of the regs to operate an aircraft contrary to any published limitations.

Therefore, if you operate in icing conditions in an aircraft not certified for that, you are busting a limitation.