Personal Minimums

[Fritz1]

as stated multiple times minimums above what is written in the approach plates and in the POH are personal and evolve dynamically, now and then I fly for business, what has always helped me is a simple time buffer, if my meeting is in the morning I fly the day before, and start running weather forecasts 2-3 days before I actually fly. I am fortunate enough in that most of my work is done through the internet or over the phone, so another night in a hotel is not that inconvenient. I dread the situation where I have to make a landing to make an appointment, sticking that landing because the mail has to come through is a job for people who fly for a living, as private pilots we have the luxury to bail out if and when things just don't look right, live an fly another day

[Joshua Blackh4t]

A slightly different sort of minimum I learned years ago:

If more than 3 mistakes happen before take-off, then don't fly that day. (Or if its important, work out what you'll do to mitigate that you're not in the right headspace)

I mean mistakes like forgetting a fuel drain, trying to start the engine without priming it, making a radio call before turning on the radio.

The point being that we all occasionally make mistakes, but when there is a pattern, then we are likely to do something serious unless we change it.

And it might just mean "you're stressed and dehydrated, drink some Gatorade and take 10 minutes to focus on the flight and stop thinking of work"

[varlajo]

1 minute ago, Joshua Blackh4t said:

If more than 3 mistakes happen before take-off, then don't fly that day.

I like this. Sometimes happens in an unfamiliar environment or circumstance, and definitely a good trigger to at least step back and evaluate. 

[Scott Dennstaedt, PhD]

For those interested in personal weather mins, I'll be doing a presentation at SUN 'n FUN on Thursday, April 3rd at 10 a.m. in room CFAA-01. This will also cover how I've integrated personal weather mins into my progressive web app which is designed to identify and quantify personal risk for a route. Hope to see you there!

Also, check out this article from FLYING magazine that I wrote last year about personal weather mins. 

[Scott Dennstaedt, PhD]

On 3/7/2025 at 3:38 PM, varlajo said:

I like this. Sometimes happens in an unfamiliar environment or circumstance, and definitely a good trigger to at least step back and evaluate. 

What I like about this as well...is that you caught your three mistakes. The issue occurs when you don't.  

[Pinecone]

11 hours ago, Scott Dennstaedt, PhD said:

What I like about this as well...is that you caught your three mistakes. The issue occurs when you don't.  

I think part of the idea is if you caught 3 mistakes, how many did you miss?

[Scott Dennstaedt, PhD]

8 minutes ago, Pinecone said:

I think part of the idea is if you caught 3 mistakes, how many did you miss?

Yep, it only takes one mistake to ruin your day. 

[Joshua Blackh4t]

11 hours ago, Scott Dennstaedt, PhD said:

What I like about this as well...is that you caught your three mistakes. The issue occurs when you don't.  

Its also statistics.

I had someone once give a lecture on construction workplace safety. One of his ideas is this:

Major accidents are largely random and unpredictable, so they are hard to avoid. BUT we know they happen at a relatively constant rate compared to minor accidents. SO, if we can cut down on small accidents we automatically cut down on major accidents.

In construction thats like avoiding "harmless" things like splinters, hitting thumbs, dirt in you eyes, tripping over things etc. In aviation its all the little things that don't really matter but make us look less professional. 

[EricJ]

2 hours ago, Joshua Blackh4t said:

Its also statistics.

I had someone once give a lecture on construction workplace safety. One of his ideas is this:

Major accidents are largely random and unpredictable, so they are hard to avoid. BUT we know they happen at a relatively constant rate compared to minor accidents. SO, if we can cut down on small accidents we automatically cut down on major accidents.

In construction thats like avoiding "harmless" things like splinters, hitting thumbs, dirt in you eyes, tripping over things etc. In aviation its all the little things that don't really matter but make us look less professional. 

In the Swiss Cheese model it's essentially doing what you can to minimize the number and size of holes in each slice.

[Pinecone]

11 hours ago, Joshua Blackh4t said:

Its also statistics.

I had someone once give a lecture on construction workplace safety. One of his ideas is this:

Major accidents are largely random and unpredictable, so they are hard to avoid. BUT we know they happen at a relatively constant rate compared to minor accidents. SO, if we can cut down on small accidents we automatically cut down on major accidents.

In construction thats like avoiding "harmless" things like splinters, hitting thumbs, dirt in you eyes, tripping over things etc. In aviation its all the little things that don't really matter but make us look less professional. 

Occupational Health and Safety Professional for over 40 years here.

That is not "his" idea.  It comes from research done in the 1930s. by a guy named Heinrich.  He studied a bunch of similar mishaps (we don't call accidents) and came up with the Heinrich triangle, where there is a ratio of 300 to 29 to 1.  That is 300 near misses or minor injuries to 29 serious injuries to 1 major injury or death of similar mishaps.  And that, as you mentioned, fixing the near misses or minor injuries tends to prevent the serious and major injuries. 

The problem is, getting people to report those minor mishaps.  This is why most professionals are against safety incentive programs.  That is, if we don't have any mishaps, people get a bonus or such.  This just makes people hide the minor mishaps to not screw up the bonus, and the first time you find out there my be an issue is with a serious or major mishap.

Sort of the idea behind the ASRS system.

In general, most mishaps are caused by the unsafe acts of the people involved.  From willfully violating safety protocols to "hey, watch this" situations.  About 85% are from this.  about 10 - 15% are unsafe conditions.  That could be something broke or something was setup wrong.  Only about 1 - 1.5% of mishaps are truly accidents (why we call them mishaps).  And those are the ones you can't do anything about.  In the class of acts of God.

[wombat]

@mooneygirl recently did a presentation at the Pacific Northwest Aviation Conference & Trade Show that focused on psychology and personal minimums.  I bet she's got plenty to add to a thread like this.