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Owner's Corner

Lloyd Stephens, Aircraft Owner WVFC

On Personal Minimums and Risk Management 

Frequently in the winter months, when we get clear sunny days and perfect flying weather in the Bay Area, California’s central valley will be covered in low clouds and fog.  Generally the tops of this layer are at or below 2000 feet and the air is perfectly clear above, while on the surface visibilities start out being about 1/4 mile in fog, vertical visibility 100 to 200 feet, and it may improve only to 1 mile with a 400 to 500 foot ceiling by late morning or early afternoon, and never improve to better than that. On those days flight service advises “VFR not recommended” over the valley.  It is beautiful to fly over the central valley on these days--it looks like you are flying over a giant snow field--and the airports on the other side (Jackson, Columbia, etc.) are in the clear.  But should you do this and, if your answer is yes, under what conditions?

This issue came up recently in a discussion about “personal minimums.”  I am not a flight instructor.  I am a commercial/instrument rated pilot, but I have more than 3000 hours of experience flying in all kinds of weather.  It always raises eyebrows when I say that I don’t really believe in personal minimums. That is not to say that I think a newly minted private pilot should be flying the same as I do, or that a new instrument pilot should load his friends in a plane and set off for Reno at night in a storm.  (When I learned to fly we were prohibited from landing on any runway that was less than 3000 feet long.)  But it’s not that I don’t have personal minimums, it’s that they are flexible, so, as I like to say, “it depends.” 

What I think is that what you do and what your minimums should be, depends on the conditions, and your ability.  It’s about managing the risk and maintaining your options.  It is one thing to make an instrument approach to 200 feet and 1/2 mile visibility when the tops are 800 feet and it is clear above with a good VFR alternate nearby, and quite another to attempt such an approach when it is raining with tops layered to 25,000, your alternate is right at minimums, and VFR is a long way away.  I remember sitting on the ground for a couple of hours at North Bend, OR, when the airport was below IFR minimums, because the nearest airport that was not below minimums was 1 1/2 hours flying time away.  This despite the fact that the tops were only a few hundred feet up and it was clear above.  Other planes were departing, but I didn’t.  I just didn’t like the fact that my options were so limited if I had a problem after departure.

If you talk to instructors, they will tell you that one of the most difficult things to teach to new pilots is judgment.  One of my friends who is not a pilot was discussing aircraft accidents with me recently.  He and I agreed that the majority of aircraft accidents happen because of bad decision making.  His theory is that man loves to gamble, and that many pilots gamble on making it safely to their destination despite the fact that the odds are not in their favor.  He said, if you want to gamble with your life, that’s one thing, but leave your family and friends behind.  If you are a gambler, setting inviolate personal minimums could save your life.  But if you compromise on those minimums, you’re not any better off than if you didn’t set them in the first place.

Life is not without risk, and that is particularly true of flying in small planes.  But my approach is one of risk management to minimize the risk factors and to, as far as possible, maximize your options.  We are fortunate in that for most of us, unlike airline and cargo pilots, flying is something we can choose to do, or not do.  If you choose to fly only on clear, calm days, and not go far from the airport, you have few decisions to make and you’re not likely to get in much trouble.  Those of us who use the airplane as a transportation device, however, may have a lot of decisions to make.   I am an advocate for taking small steps at first, but gradually pushing your comfort envelope by taking larger steps--going to new airports, getting more training (such as a commercial license and/or an instrument rating, and getting some experience flying in different conditions--before you try a long cross-country with friends or relatives when you “have to” get there, especially in questionable weather. (After I got my instrument rating I used to seek out cloud layers between about 4000-8000 feet, and clear below, just to practice my instrument skills.)

Flying out of the Eastern Sierra (Bishop and Mammoth) has taught me a lot about making those decisions.  You can almost always fly somewhere out of Palo Alto or San Carlos, even if you have to wait for the fog to burn off.  But that’s not the case out of the Eastern Sierra airports.  Winds that blow the big semi trucks over on the highway, mountain waves with associated rotor clouds, and clouds obscuring the Sierra combined with low freezing levels and rain or snow, can keep you on the ground for days (sometimes weeks) unless you want to gamble on making it out safely.

I believe in getting a thorough weather briefing (I like the NWS site for area forecast discussions and aviation weather), doing a thorough pre-flight, considering my options and alternatives, and my currency and skill as a pilot, then deciding if the flight is within my comfort level before I go.  If I encounter conditions enroute that I don’t like, I don’t hesitate to land somewhere other than my destination to wait for them to improve.

Back to the central valley, I have flown across it when it is obscured by low clouds on occasion enroute to Bishop, and I have gone over there to practice instrument approaches in actual conditions at Stockton or Modesto.  (It is a great way to gain more confidence in your ability to make approaches to minimums.)  When I told one flight instructor that I did this, his response was that it was not a good thing to do because it limited your options if you had an engine failure.  And that is true, but it is a trade off.  Engines do fail, but not frequently, and it is difficult to find more benign conditions in which to make actual instrument approaches to minimums.  Also, I don’t fly over or into the central valley when visibilities or ceilings are very low.  I want a minimum of 300-400 foot ceilings with at least a mile (and preferably more) visibility beneath the clouds, just in case.  That’s enough to give you some maneuvering ability below the clouds.  Not without some risk, but with good VFR above and VFR airports not too far away, I’m comfortable doing that.  The benefits are relatively high and the risk is relatively low.  For you, that may not be true.  As a pilot, you have to make that decision.  Do so wisely, and fly safely!!