Chris Findley, a flight instructor and the founder of myFlightCoach.com, has written a great post for the Let’s Go Flying blog about personal minimums. Chris began his post by telling the story of how a student of his once showed up to a training session knowing what the current weather was like but not knowing what the predicted weather was going to be. This led to the discussion about personal minimums and as Chris pointed out:
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.
Chris noted that this will obviously be different for each and every pilot and that it will depend on factors such as a pilot’s training, experience, physical condition and health along with atmospheric conditions, aircraft and type of flight. However, he also added that what is most important is that a pilot thinks through these things ahead of time in order to be able to make a good go/no-go decision.
Chris then noted that flight instructor and ATP Darren Smith has written a great personal minimums checklist (which can be downloaded here) 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?
In the case of one new pilot that Chris knows, his personal minimums checklist is simply:
Wind: X knots headwind, X knots crosswind
Ceiling: X,XXX ft
Visibility: X miles
Thunderstorms:for XX miles
Experience: X Takeoffs and Landings within XX days.
And for him, if these conditions are not present at the time he plans to take off, he remains on the ground.
Chris ended his post by saying that personal minimums give pilots a framework for making both good and solid decisions and then he mentioned an old adage well worth repeating again:
Better to be on the ground wishing you were in the air, than to be in the air wishing you were on the ground.
I heard a lot about "personal minimums" when I was a student pilot (and later), but it didn't do me much good then. Especially as a student, since a lesson would simply be cancelled if the weather was questionable. I would ask my instructor what those values of 'X' should be, approximately, for me as a young pilot, but he couldn't give me any actual numbers to work with and of course I didn't want to fool around on my own with marginal weather conditions to see what my personal limits were.
Now I try to check the weather conditions after my flights, to try to get an idea as to what those actual numbers might be , but it's still not as useful a system as its advocates think for a young pilot. I can say, "Yesterday I made a landing on runway 27 at ___ airport with 5 knots of crosswind in a Cessna 172, and everything was fine and didn't die or damage the plane" but that doesn't necessarily mean that my personal limit is 5 knots crosswind. But how am I to really know how much more I could take, before I get myself into a questionable situation?
The big danger with this approach is "I got away with it last time so it must be within my capabilities." I was watching a couple of professional pilots in a flight sim two weeks ago and they just had a set of rules about fuel, weather etc. The more planning and decision-making you do on the ground, the less you have to worry about in the air. Personally, I use a risk assessment which I based on one used by Alaska Airlines but modified slightly for my own types of flights. What it does is give me a sense of how dangerous a flight might be and where the risk factors are so that I can make extra preparations and plans. This mix of minima and risk assessment works for me (so far!).
Yeah, I know it's not a great approach for those reasons. But it doesn't do much good either to tout 'personal minimums' without describing how one goes about finding out what their numbers ought to be, and particularly not for students who aren't yet used to thinking in terms of knots or feet per minute or thousands of feet. And it's something that frustrates me with CFIs and safety seminars, where they talk about something that sounds like a great idea but don't talk about how to actually implement it, or how to know when you've got something right.