Flight crews routinely make judgment calls on virtually every flight. Most of those calls are- thankfully- relatively easy for most of the time. On those few other occasions- however- the judgment call flight crews face involves a seriously difficult- or perhaps even a dangerous decision that will impact all decisions that follow on that flight – maybe all future flights- too- if the decision goes bad.

Dave Higdon  |  01st January 2011
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Dave Higdon
Dave Higdon

Dave Higdon is a highly respected, NBAA Gold Wing award-winning aviation journalist who has covered all...

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Limit Switches:
Company Minima set standards for sitting it out.

Flight crews routinely make judgment calls on virtually every flight. Most of those calls are- thankfully- relatively easy for most of the time. On those few other occasions- however- the judgment call flight crews face involves a seriously difficult- or perhaps even a dangerous decision that will impact all decisions that follow on that flight – maybe all future flights- too- if the decision goes bad.

That decision may be whether to complete the latest business trip- or sit tight. This call generally comes up en route- long after execution of the initial decision to embark on the trip - so we’re talking questions of whether to continue- unbending to the final destination- or to divert.

The easy calls seldom generate even a ripple. The hard calls- if there’s any room for debate- seldom come easily. One way to reduce the debate is to create- document and use a set of personal or corporate minima.

Flight Instructors teach would-be pilots about limits from the beginning of their flight training. And limits come into play again and again throughout a life of flying. You won’t get far with any Certificated Flight Instructor without knowing when VFR conditions give way to IFR’s limitations.

Instrument flying itself is awash in highly specific minima mixed specifically for a particular airport: Standard Terminal Arrival procedures- Standard Instrument Departure procedures and the various approach technologies all employ minima established more or less empirically. Those limitations set ceiling and visibility requirements for different procedures.

Further- such minima define the legal limitations. While specific to location and equipment- they apply to a broad- generic set of pilot skills. And those skill requirements are largely disconnected from any assessment of the pilot’s capabilities once the pilot successfully completes instrument training and practical tests – and is up-to-date on currency requirements.

Of course- while the government officials at FAA set the limitations for much of our flying- it’s up to us to decide when and where to tackle conditions at the limits. And that’s where personal minima come into play. Personal minima involve a pilot creating a set of limitations that honestly recognize individual limitations- experience deficiencies or simple comfort level.

Corporate minima effectively do the same in a fashion standardized for all the individual pilots and flight crews flying for that specific operator.

In formal terms personal minima refer to an individual pilot’s (or company’s) set of criteria- guidelines- procedures and rules created as a cushion between your skills set and the requirements of the circumstances of the moment. The idea is to establish an objective checklist for gauging whether to take- or continue a flight that applies a realistic assessment of limits for the pilot’s current level of proficiency based on recent experience- training- and overall capabilities of the aircraft and crew.

By weighing up whether conditions of a proposed flight will clash with any of those elements- the pilot makes a more-objective assessment of the trip’s potential. If the flight proposed requires use of skills or procedures the pilot hasn’t applied in months or years- maybe those conditions are not the best place to fly.

If the pilot has demonstrated the skills- but hasn’t exercised some elements since a biennial flight review or instrument refresher- you should ask yourself whether that pilot really wants to bet his or her life that they can still execute safely and smartly? Some proponents go so far as to encourage the creators of personal or company minima to examine the efficacy of some procedures in some regions and weigh whether to put those procedures off-limits in certain conditions.

For example- the personal or corporate minimum might require a precision approach for all night IFR conditions – or- even more fundamental- impose a restriction on merely beginning an instrument approach unless conditions are well above the approach minima. If an ILS has minima of 200-foot ceiling and 3/8 of a mile visibility- the self-imposed limitations may call for no less than 500 feet and a half mile – or more.

There are regulations against approaches below minima; but no law exists that says a pilot must try at such levels.

According to research by NASA’s Aviation Safety Reporting System- more than seven in 10 in-flight incidents occur because of a mistake made before the flight even departed.

Other research and analysis of accident and safety statistics for General and Business Aviation lay blame on “pilot error” in something approaching two-thirds of all accidents. In some instances- pressure to complete a flight factors into upwards of 40 percent of accidents that befall business aircraft – in particular owner-flown aircraft. That pressure to proceed can originate internally or externally.

Too often the perpetrator went against instinct – sometimes even against obvious conditions and common sense. Source notwithstanding- succumbing to pressure your gut instinct tells you to resist is rarely a smart decision where airplanes and people mix.

External pressure can- nonetheless- be formidable: The boss- for example- or the executive in charge of “the big deal” of the trip might have an interest in seeing a flight proceed- particularly if it’s to conclude a transaction. So the pilot calling off a flight- due to weather- pilot fatigue- or a questionable system in the airplane- could generate pushback.

While the opponents of instinct may be capable of assessing the business arguments- they generally lack qualifications concerning weather- airplanes or flight circumstances.

Keep your perspective: these folks are responsible for the conduct of business - not- ultimately- for returning both aircraft and occupants safe and sound.

In some operations the people calling the shots for the company and piloting the airplane are the same person. That internal fight can be as testy and difficult for the individual as it is between two different people. The business owner half of the brain brings to the fore all those concerns of that position:

Impact on the company- the possibility of damaging the firm- or losing a client or revenue… Meanwhile- the aviator side of the brain faces the risks and challenges of piloting the mission in question.

While safety authorities can’t concretely peg owner/pilots for doing a poorer job of making such calls than for-hire crew (or even employee/pilots) statistics do show a greater propensity for owner/pilots of business turbine airplanes to account for a higher percentage of safety problems. And- as usual- typically it’s a judgment call that underpins the problems suffered.

When the debate involves two people- deciding on the proper course should be no more difficult than the pilot making the call based on safety-of-flight issues- and only safety-of-flight issues.

But the two parties being human- usually in a supervisor/staff relationship- may make for a difficult time for the pilot or flight crew to resist the pressure to follow other factors – with the same sort of results as when the debate involves only the two perspectives of the same person- who happens to have the pressure to perform and the power and ability to rationalize a bad decision.

How to counter that phenomenon – be it between two people or the two hemispheres of the same brain – remains a core element in the quest to improve Business Aviation flight safety.

With the FAA edging toward rules requiring the creation of Safety Management Systems (SMS) within the commercial segment – and Europe already requiring SMS for business turbine operations – the personal minima/corporate minima checklist is emerging as an element in that quest for improving human judgment performance.

Personal or corporate minima and checklists serve solely to recognize and act on conditions in a consistent manner – one that attempts to alleviate variability to the maximum extent possible. The FIT checklist- for example- makes the pilot address a series of topics under three distinct headings: Pilot; Aircraft; and Environment.

Under the heading ‘Pilot’ the checklist addresses pilot experience/recency of flight experience and physical condition; the ‘Aircraft’ section addresses fuel reserves for the leg- take-off and landing experience in the plane- and familiarity with its performance and its panel. Under ‘Environment’- the checklist addresses airport conditions and weather – both VFR and IFR- whether the destination has precision or non-precision Instrument approaches and take-off minima.

Too many wrong answers on any of the three categories signals the need for a new decision – or a simple “No-fly” call. Check the list at the following link:

Available procedures may proscribe a Backcourse Localizer Approach- an ADFbased circling approach and a non-precision VOR approach that brings the pilot to just above the runway with ceiling and visibility to support a circle-to-land final – 500 feet and 1 mile is common.

With equipment capable and weather at- or above minima you can fly the approach and go missed if conditions help the runway evade visual contact. But should you try? “We have a blanket company minima policy that prohibits us from flying a circle-toland approach at night-” explained one charter pilot who flies a Citation X. “Circle to land during daylight requires weather about 50 percent better than the published approach.”

For the approach he had in mind- that daylight limitation on circle-to-land means visibility must be reported at 1.5 miles or better- with the ceiling at 800 above ground level. “The company minima have been quite helpful in snuffing out a couple of near revolts in my cabin-” the pilot explained.

One favorite phrase of the head-in-the-sand members of the Ostrich Club runs along the lines of “What you don’t know can’t hurt you.” Alas- that is completely counter to aviators’ desire to know as much as possible before a flight. Weather prognoses- runway conditions- winds – in flying terms- ignorance is the polar opposite of bliss.

Ignorance seeds doubt; doubt sprouts hesitation; hesitation spawns second-guessing - mistakes. And so goes the error chain humans routinely forge en route to the crash site. Maybe it is actual landing that taxes you; if you find your landings using 25- 35 or 40 percent or more above book figures- maybe a low-and-slow circle-to-land isn’t a good choice. Can you actually complete a 360 at approach speed – and keep that complete turn within two miles (for higher-category airplanes)?

Answer the first with a “Yes-” and the second with a “No”- then maybe your personal limitations should proactively assert- “CIRCLE TO LAND FINALS PROHIBITED!”

If you routinely need 5-200 feet to clear a 50-foot obstacle- land and stop when the book number says the airplane needs only 4-500 feet- maybe your individual limits should cite- “NO RUNWAYS SHORTER THAN 5-200!”

Safety statistics with NTSB- AOPA’s Air Safety Institute- and NASA’s Aviation Safety Reporting System (ASRS) can all provide insights into the efficacies of different approaches and other long-odds situations you may want to keep out of your own personal operations specifications.

But at the end of the whole process- it’s the smart pilot who’ll create the personal-minima checklist – and it’ll be the wise pilot that adheres to it- when all other forces urge otherwise.


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