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Minimum Descent Altitudes and Personal Minimums

There’s something out there called the “Federal Aviation Regulations”, affectionately known as the “FARs” that put into written codes of law everything a pilot and an airplane can and can’t do.  (Be careful because some of the regulations apply to passengers also.)  The FARs are very specific and painfully detailed as only federal laws can be and carry all kinds of serious consequences administered by the FAA through a series of Federal Aviation Courts for those who fail to comply.  Among thousands of pages of other things in those regulations are mandates for specific altitudes that pilots can descend to and land an airplane depending upon specific minimum weather conditions and visibility – something we call “published minimums”.  These are the “MDAs – Minimum Descent Altitudes” – and change at various airports, various certification and currency of the pilot and equipment that he/she is flying.  Generally a pilot must be out of the clouds and haze and see the runway by the time the plane reaches 200 feet above the ground in order to land and with a typical descent rate of about 600 feet per minute that means a pilot can take himself and his passengers to within 15-20 seconds of sure death before he is required to climb away from the airport and try again with plan B.  When this happens it  is something equally affectionately known as “a missed approach”  or “going around” and specifically what the pilot does after the aborted landing is also spelled out in publications mandated in the FARs.

Low time pilots are often told by their instrument instructors to adopt “personal minimums” and not push it too much until they gain experience in bad weather so that they might be more likely to execute a missed approach at 500 or 600 feet above the ground which gives the new pilot a whole minute or so leeway before certain death if their descent profile is not precise. But let’s take this out of the cockpit and into our personal lives since this is a very useful concept for those of us who preach use of the “high reliability mindset” for patient and personal safety.

You can adopt personal minimums for everything you do if you have that mindset.  To start let’s talk about personal minimums for safe driving.  I have a lot of them and with a new teen-age driver in the family I have spent a lot of time teaching them to my son as he learned to drive.  The first one is simple; I NEVER have a drink – even a glass of wine – if I am going to drive, NEVER, Period.  So my absolute personal minimum is zero alcohol.  I am never the first car into an intersection when the light turns green in spite of my 15 year old  giving me that exasperated teen-age green lightsigh with a “Dad – the light’s green”.  I never enter the intersection first because I assume that the oncoming cars do not have my next personal minimum for safe driving which is I never rush a yellow light.  With that personal minimum I am also never the last car in the intersection rushing to beat out the impending red light.   NEVER.  I always make a full stop at stop signs under the assumption that nobody else will and I want the time to see them – it doesn’t add any time to my trip just more peace of mind.  I never hold a cell phone and talk on it and I never send a text message while I’m driving – that’s just pure stupid risky behavior but I challenge you to drive more than a minute or two and not see at least half the other drives looking down at their phones.  So if they aren’t looking at me I want to see them and avoid them.  My personal minimum for blinker lights is also zero – I never turn or change lanes without using them just in case I missed the guy in my blind zone and maybe he will see my blinker and avoid me – well maybe if he’s not typing a text message.

So let’s take this even farther from cockpits and into our practice of medicine and surgery.  This is where I will (partially) agree with those who say aviation safety methods don’t map over into healthcare and it is because all of these aviation safety behaviors are written into laws so it’s easy to know the safety “space” and stay within Federal safety standards – just follow the law.  However, heathcare professionals  are provided no such guidance and there are no laws for safety limits in our practice.  That is why it is even more important to adopt our own personal minimums as part of the high reliability mindset.  For example – my person minimum to start an operation without a time out is zero – NEVER, period.  I have personal minimums about checking my own x-rays – I never allow one of my residents or myself to do a procedure without reviewing the side, site and patient – NEVER, period.  I have the same personal minimum for use of checklists – I never fly without my checklists and I never do a complex procedure in the ICU or an operation in the OR without a checklist – NEVER, period.

This is easy stuff to adopt in your own personal practice of medicine and even your own activities during the day.  Think about an absolute minimum that you will not go beyond and just never go there, NEVER, period.   And when you have your own set of personal minimums and follow them seriously, you are well on your way to practicing the high reliability mindset.  Your patients and your passengers will be very appreciative of your thoughtfulness.

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Posted in High Reliability Mindset, Human Factors, Patient Safety.


4 Responses

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  1. skulljockey says

    Great blog today. I do love the idea of one’s personal minimal set provided some structure in the chaotic health care environment. Do you think that transference of such minimums prevents one from ever being/ working outside of the box? A reflective paralysis of sort ? How do the minimal personal standards of individuals facilitate /collide in a chaotic environment? Rhetorical questions of course! It is amazing that you are sharing safety secrets in a way that many other surgeons have been too timid to reveal in the past as a metric of weaknesses instead of strength. All of the safety nerd surgeons like me who have been labeled in their past as “unconfident” because of their “ safety conscious ” are the newest members of your fan club. I think that this is the best of your blogs so far…looking forward to the next.

    • kenstahl says

      Thank you for these very insightful comments and provocative thoughts. I’ll weigh in and hopefully a few other folks out there is cyberspace will join the conversation. I believe personal minimums are a measure of each of our own professionalism. These sets of behaviors define the limits of the amount of risk we are willing to take with our patient care and as such do define how far “outside the safety box” we are willing to go. The big risk is to be outside that box and not know it – so if we set in advance – limits to how far we will stray we will be able to control risks. In no way are minimum standards and risk levels meant to cause paralysis in decision making, only prevent us from getting so far astray that when we look down – we become paralyzed and unable to get back into the safety space.

      • skulljockey says

        So assuming that one knows that they are outside the safety box, is it the context of the situation, the level of expertise or the personal minimumns that determine how “far” one is outside the box and do any of these provide a vehicle to find one’s way back into the safety box?
        Perhaps, to continue your driving analogy in the blog, being outside the box is like driving in someone’s blind spot? The less time one spends there, the better!

    • Tony Kern says

      Skulljockey
      Interesting point that others would label those who temper their judgment with tools like personal minimums “safety nerds” or “unconfident.” I’m just a knuckle dragging pilot but if I recall from my logic classes those are “ad hominem” arguments, the kind people make when you must attack the person because you cannot logically attack their position. I’d say you are on the right track, and personal mins are not just for new pilots with low experience. All experienced pilots I know have a set, even if they don’t talk much about them.



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