by Chris Findley, CFI
“What is the weather predicted to do while we are flying? And will the changes that occur be beyond your capabilities?”
My student arrived on time and, after exchanging pleasantries, I asked him about the weather. It was a local flight, but I had been on my student to begin sharing in the decision-making process. I had begun to sense that he simply relied on my level of comfort and advice to make the decision to fly or not.
“AWOS says the ceiling is 3000 feet, with the wind 260 at 6.” he said, already heading for the flightline.
“Whoa…hang on.” I said. “You have to understand that weather is dynamic, not static. It’s always changing. What is the weather predicted to do while we are flying? And will the changes that occur be beyond your capabilities?”
He looked at my blankly for a minute. I explained, “Say we take off and 2 things happen: 1.) The ceiling begins to drop as a warm front begins to pass, from 3000 to 1600 feet and 2.) As it does that little westward wind becomes 12 gusting to 18. Would you, particularly where you are in your training, want to take off solo in those conditions?”
“Well, no.” he said.
I told him that we needed to talk about more than existing weather, but predicted weather. AWOS is great, but I’ve found that it is sometimes as informative as the rock-gags that say, “If the rock is wet, it’s raining. If it is hard to see, it’s dark.” So we have to do more preparation than simply phoning the AWOS on the way out to the field.
All of this brought us to a discussion of personal minimums. Personal Minimums are exactly what they say they are, they are a way for you and I to think through the conditions of a flight and determine, outside the pressure of the moment, what is safe and reasonable for us.
This obviously be different for different pilots. It will depend on your training, experience, physical condition and health, atmospheric conditions, aircraft, type of flight to be conducted, etc. The essential thing is to have thought through these things enough to be able to make a good go/no-go decision. Flight Instructor and ATP Darren Smith has a great checklist that is broken down into four simple categories:
1.) Pilot: How many takeoffs/landings have you had in the last 90 days? Hours in make/model of aircraft? Are you familiar with the terrain and airspace? Physically, have you been ill or are you taking any medication that might impair your skills? The old “I’M SAFE” acronym comes to mind– Illness, Medication, Stress, Alcohol, Fatigue, Emotion. Have you eaten?
2.) Aircraft: Fuel reserves in place? Experience in type? Aircraft performance- weight, density altitude, performance charts? Equipment on board-functioning properly, updated if necessary, required documents and inspections?
3.) Environment: Wind? Crosswind? Adequate runway? Weather forecast? Ceiling/Visibility?
4.) External Pressures: Alternate plans if you can’t complete the trip by air? Plan if you are delayed? Other pressures to complete the flight?
The benefit of personal minimums is that they give us a framework for making good, solid decisions. How many pilots have gotten themselves into trouble because they simply took off into a situation that was beyond their limitations?
But it might be good to start with a very simple flow chart. For my students, I ask them to describe for me what they perceive to be the edges of their skills and experience. For one new pilot I know, whom I’ll call Jim, his personal minimums for day VFR look like this:
Wind: 10 knots headwind, 7 knots crosswind
Visibility: 5 miles
Thunderstorms:for 15 miles
Experience: 5 Takeoffs and Landings within 30 days.
For him, if these conditions are not present, he doesn’t go. With experience I’m sure things like the crosswind component will increase and he might feel more comfortable under a slightly lower ceiling. But this plan keeps him safe. When he’s ready to go beyond these he’ll hopefully obtain some time with an instructor until he feels like he’s ready to increase his own limitations.
The benefit of personal minimums is that they give us a framework for making good, solid decisions. How many pilots have gotten themselves into trouble because they simply took off into a situation that was beyond their limitations? We want to avoid that. We should all be constantly learning, constantly pushing ourselves to become better pilots, but not at the risk of our safety or that of our passengers. As the old adage says, “Better to be on the ground wishing you were in the air, than to be in the air wishing you were on the ground.”
If you would like to read more on Personal Minimums I’d suggest you check out, the article by Susan Parson available here on the FAA’s website >>>