SVFR
When you are flying VFR in Classes C, D and E airspace and in radio contact when weather conditions become below VFR minimums you can request get a SVFR clearance.

Requires clearance at airport
1 mile flight visibility
Clear of clouds
Night: IFR airplane and pilot

Visibility
Even under the new METAR system visibility is usually given in the U.S. as statute miles. Ground visibility is reported at airports as distance over at least 50% of the horizon. The pilot is bound by the reported ground visibility and must have the required visibility to operate in Classes B, C, D, or E airspace. See FAR 91.155(d) However, the pilot will be using flight visibility while flying. Flight visibility is the distance you can see in the direction you are flying. When visibility is not reported you can fly using flight visibility. See FAR 91.155(a). Touchdown zone visibility is measured by a transmissometer and is given as visual range in feet or fractions of miles.

Haze
Haze can be a serious problem where spatial disorientation can follow lack of situational awareness. You can out-fly your visibility and checkpoints. Haze is caused when the air contains relatively high amounts of water vapor and dust particles to the point that visibility is diminished. An airport at less than five miles may be reported by you to be up to fifteen miles away because it is so hard to see. You can see down but the slant range visibility is an illusion and deceptive. The position of the sun low on the horizon either morning or evening that requires you to look into it is particularly hazardous. In this case my recommendation is to over fly the airport and come in with the sun behind you. The difference in visibility is dramatic.

Go-No Go Decision:
--VFR flight into IFR has only 10% of the accidents but 82% of the fatalities.
--The most difficult forecast is ceiling and visibility.
--Any flight into marginal conditions is more likely to be in error. Error either way that is.
--The greatest errors occur in time. The weather will happen but betting on when is a crap shoot. Don't bet on improving
weather at the time forecast.

General Cautions
1. Reduced visibility and haze may require instrument flight.
2. Morning flights are smoother.
3. Approach ridges at 45-degree angle
4. Fill tanks on landing to avoid night condensation.
5. Always carry water and have it available.

Learn to watch trends. A rising altimeter setting indicates improving weather. If the temperature/dewpoint spread is getting wider then things are improving. If in the air, don't fly over an undercast unless you know you can reach VFR. Don't fly under a ceiling that is forcing you ever lower. Winds that are different than forecast are advanced warnings that other parts of the forecast are going to be wrong.

1. NoGo if known icing
2. NoGo if ice forecast at flight altitude
3. NoGo if forecast conditions may be worse. Don't fly into deteriorating weather conditions.

VFR into IFR
Unintentional VFR into VMC can happen to anyone. The ability to forecast just when a weather change is going to occur is still for the future. Even the most careful pilot cannot always accurately time his weather avoidance.

I live and fly on the West Coast and never cease to be surprised with the way weather seems to evade accurate prediction. I try to be selective in my weather flying by taking my students into marginal but improving conditions. Improvement seems to progress more slowly than deterioration. I have had fog close my home field from full VFR to zero-zero during the time of preflight. We get both avection and radiation fog often in consecutive days depending on conditions. Many of the S.F. Bay valleys have micro-climates that defy prediction.

I do believe that a 'California' instrument rating is a very valuable flying asset but extremely difficult to keep current. I believe that both the private and instrument ratings are best acquired during the late fall and early spring since it gives the trainee exposure to the entire weather gamut available over a period of four or five months. Woe is to the pilot who learns during the summer because they are doomed to remain on the ground for many months before summer comes again. A pilot needs exposure to the vagaries of coastal weather that cycles from sea to central valley and back again every eight days. It has taken me many years of study and observation to evade the mistakes of the weather forecasters.

California coastal weather is always changing. Often the status of good or bad is contradictory depending on the desires and intentions of the pilot. I have lately cancelled a number of flights because the weather has not been IFR enough for what I wanted to teach. At the same time I have been unable to do a number of SVFR lessons because the weather improved too rapidly.

The field of weather prediction has still to accurately time the arrival of weather consistently. The coast has a lack of
airports and a corresponding lack of PIREPS. A PIREP is real-time weather for a specific place and time. This is weather you can believe. Be cautious in reliance on ASOS and AWOS. My home field has had one for nearly two years and it is yet to be certified for use.

The weather patterns are a changing worldwide. When people from all over the world come to San Francisco they must be prepared to unusual weather. July can be quite cold; last December was the third warmest on record. Once a year thunderstorms are now occurring monthly. Storms line up on the jet-stream and march through with only two-day breaks. Occasionally, a storm will pause and drop rain for three days before moving on.

You can avoid weather problems by staying on the ground. You can fly in certain 'bad' weather conditions if you always have a backdoor escape route and know exactly where you are. Getting on the ground is always a desirable option. Get down and settled before dusk. Any weather will be worse at night. Be ready to change any preconceived plans. Be prepared to wait-out the weather.

Weather Planning
Visibility is the most obvious weather factor likely to abort a flight.
Most weather factors can be flown under, over, or around. Not so easily with low visibility.

Low Visibility Effects:
--Avoidance of embedded weather is difficult.
--Reliance on pilotage and VOR navigation becomes uncertain.
--Disorientation is a real possibility. Use GPS if possible.
--CFIT (controlled flight into terrain) becomes a hazard.
--Avoid being caught on top.
--Don't try to out climb a rising cloud. You can't.
--Live with rain. When it exists avoidance except for improved visibility is unlikely.
--Don't fly under dark clouds that may be the base of an embedded thunderstorm.
--Avoid turbulence. Don't fly into forecast turbulence or ice.
--Note how winds affect your adherence to route and planned speed.

En route Decisions
Know where the severe weather is.
Know where to go to avoid problems.
Check the weather often on 122.0.
PIREPS are your best friends.
Don't expect to influence the weather.
You won't go wrong making the safe decision

PIREP
Begin by just calling up and the name of the nearest VOR and relationship to a prominent checkpoint if possible. You can help the system of giving the PIREP work better by giving the information in the correct order. Use navaids for location not local checkpoints. Give your aircraft identification, type, altitude, flight type, departure point, destination, and route.

Continue to Next Page