VFR Weather Minimums
 

Hi

Following scenario:
You are at an uncontrolled airport, you have listened to the latest weather (ASOS/AWOS), accordingly the received information, the weather conditions are below basic VFR. But when you (as the PIC) look around, it seems to you that the weather is still good enough for VFR. Is it mandatory to get a SVFR clearance, or is the judgment of the pilot crucial in this situation? What are the reglementations saying?

Greetings
Sam

How do you get a SVFR clearance from a non-towered airport?

If the airport does not have a control tower but lies for example within an Echo to SFC airspace, you can contact the controller to get issued a SVFR clearance out of the airspace.
The VFR minimums are regulations, and are as far as I can see not depending on the PIC agreeing with them or not

....and if it doesn't lie "for example within an Echo to surface airspace" or, indeed, if it doesn't lie within the United States (the OP says "Switzerland")?

See, this is the trouble we so often encounter omn PPRuNe when you only ask half a question.

In the scenario where you are about to depart from a non-tower aerodrome which has no weather reporting and lies inside someone else's CTR, I imagine it's up to you to assess the weather conditions to the best of your abilities and make a decision as to whether you are legal to go or not and under which conditions (and of course, whether it's a good idea at all). E.g., if your aerodrome looks like in VFR conditions, then you may depart as usual, but if you're then transiting close to a controlled airfield where the METAR shows viz requiring SVFR, then you must request SVFR for the transit. That's just my interpretation anyway--I could very well be wrong, but I don't think the rules go to that level of detail.

In practise, nobody will care unless you have a prang, but try to be sensible.

But the ASOS or AWOS is automated and what is, when it says that the weather is right at the edge of basic VFR conditions, but a little bit below (accordingly to ASOS or AWOS), but you as the pilot judges that the weather is still good enough for VFR, do you then have to get a SVFR clearance or is it up to you as the pilot to decide that you have to get one? Are the ASOS / AWOS information mandatory to comply with?
(Class E uncontrolled airport in the US). And what is when the ASOS / AWOS information is obviously not correct? Are there some regulations, or best practices?

Thanks

I've no idea how it works in the US, but in Europe:

if you are outside controlled airspace you cannot get SVFR

If the weather station reports below VFR minimums you will have the evidence against you in case you prang.

If the weather station data is seriously and obviously duff, you need to bring it to someone's attention and have it taken offline/NOTAMed/etc., while it's fixed. In the meanwhile, the accuracy of your eyeball weather assessments will presumably be judged against regional weather data, and data from nearby stations. Again, mostly only if accident investigators need to get involved :ouch:

So, I'm not really getting what it is that you're trying to ask, although I'm sure your question is not about whether it's sensible to fly in crap weather, which is what I've ended up answering. Perhaps you would care to rephrase your question a bit better? Also some background on your qualifications and level of experience would go a long way towards getting a decent answer.

Thanks for your explanation, this has already helped. Actually I have meant in controlled airspace, but at an untowered airport (like most class E surface airports).

I was just wondering, if there are some regulations which forbids to take off at such an airport without SVFR clearance, when the automated weather reports weather below VFR but its clearly still VFR.

Ok, I've missed the class E bit. Please state to which country your question refers. In France, a clearance is not necessary for VFR flight in class E airspace (except night VFR), so if the weather is above VFR minima, you just take off and fly.

If the weather is below VFR limits, but above SVFR limits (i.e., met vis on the ground >5km, in flight >1500m, cloud base >1500ft), then you cannot depart, land, or cross the airspace in question unless in reception of an SVFR clearance from the responsible unit.

In other words, if the weather is crap, yes you have to request an SVFR clearance--which btw, if you are on the ground it might very well be denied (generally in the interests of your own safety).

All the above is applicable to France, barring any mistakes I might have made. If you are talking about the States, it's bound to be completely different and you'll be better off asking a competent FAA instructor or posting in a US-oriented forum.

@LH2

Thanks for your help. Yes my question was related to the States.

The thing with the whole SVFR is: at an controlled airport (with tower), you have to get a permission (SVFR clearance) to depart at all. But when the controll tower is not in operation, then you probably not get a clearance this easily. And so I was just wondering if the automated weather report is mandatory (if it reports weather below VFR) to comply with.

Is this forum french orientated? Do you now some aviation forums US orientated?

Yes it is. You must comply with the minima for the class of airspace you're in. In some places the class of airspace changes (becomes uncontrolled) when the controller goes home in the evening so the limits could change, but there will still be limits, and if the METAR says you're below those, you cannot depart.

If the airspace becomes uncontrolled, then SVFR is not possible. If another unit takes responsibility for that bit of airspace, then you have to request a clearance from that unit.

No, just me :E This is mostly Brits and a few continentals, with the odd Merkin and Antipodean sidekicks to complete the mix.

Nope, sorry, but I'm sure others will help you with that.