Turbine Pilot

Recognize, assess, mitigate — or don't go at all

The day we first contemplated learning to fly we realized that there was some risk involved. In fact, psychologists tell us that this is part of the allure of flying — a bit of risk adds some spice to the adventure.

We make an intuitive calculation of the level of risk involved in any venture and go with it, however rough cut or unscientific. There are no right answers: Risk is relative — each individual accepts a level of risk they are comfortable with.

During the preflight planning process each pilot normally makes a series of interrelated risk assessments regarding the flight. For instance, we look at the amount of fuel on board and known rate of consumption versus the distance to destination, the probability that the winds aloft will be higher than forecast, the chance that the weather at destination may require diversion to an alternate, the possibility of air traffic delays, the accuracy of the fuel gauges, and then add a bit extra for the spouse and kids. Similar calculations are made regarding en route and destination weather, terrain over which we will fly, adequacy of the destination airport, airworthiness of the aircraft, and personal health, experience level, and state of proficiency.

This process is an example of informal risk assessment. It is a method of building a comfort zone around the flight that satisfies us regarding our own personal concept of risk. Yet this process is rather imprecise and contains no standards against which to measure our assessment. Before we get to that, first a word about risk itself.

The term often gets confused with the concept of hazards, but risk involves two factors: hazards and probability. Therefore, a risk is the combination of the severity of a specific hazard and the likelihood that the hazard occurs — severity multiplied by probability of occurrence equals risk. While some use this equation mathematically to arrive at a rate, this method is less useful than a simpler method; mentally combining the two factors to arrive at a subjective risk index. While this does not provide an absolute value, it does put things into perspective. For instance, the consequences arising from uncontained engine disintegration may contain a substantial hazard, but the probability of occurrence may be so slight as to classify it as a low risk. But a TCAS (traffic alert and collision avoidance system) resolution advisory shortly after takeoff is a great hazard with a high probability of occurrence in certain circumstances, warranting assignment of a high-risk level.

Each of us may arrive at a different level of risk after our calculations simply because our values are different; we all view the world differently and come from different backgrounds. Thus, it is important to evaluate the relative risks of your operation as a collaborative effort, involving all members of the flight department in the exercise. If you are a single-pilot operation, conversations with fellow pilots, flight instructors, training providers, and insurance underwriters should provide some useful insights.

Evaluating risk

The sum of the type of aircraft and its equipment, our training and experience, and the operating environment provides us with a level of preparedness to meet a certain level of risk. For instance, your 2,000 pilot hours, 300 of which have been spent flying your well-equipped Beechcraft King Air C90 in moderately challenging instrument conditions to airports with at least a 4,000-foot, ILS-equipped runway, and annual simulator-based recurrent training prepare you for a variety of situations in which you can operate with relative safety. But those situations are rather general. To be more specific, the details of each flight should be measured against your personal and your aircraft's capabilities to evaluate the risks involved with each situation.

To establish a baseline against which to measure different risks, a standard flight or series of flights should be established. These should be relatively easy flights so that no element of any trip listed would be greater than a medium level of risk. Then elements of flights featuring variations on the baseline may be incorporated and compared to determine whether the level of risk becomes unacceptable.

Risk above the medium category should be considered unacceptable unless some means of mitigating that risk can be found.

Standards

An essential element of risk assessment and mitigation is the imposition of standards and limitations that go beyond the minimum requirements of the federal aviation regulations. These higher-level standards flow from the realization that certain types of accidents and incidents occur more frequently in business and corporate aviation. For instance, about half of all business turbojet accidents occur during the landing phase of flight; roughly half of all business turboprop accidents occur during a combination of the approach and landing phases. Therefore, some additional standards may be required to reduce the level of risk encountered during these phases.

A common accident type for both turbojets and turboprops involves the aircraft running off the departure end or side the runway. Causal factors in these accidents include an unstabilized approach (not properly set up), excessive speed, adverse wind conditions, a wet or icy runway, and touching down past the normal aim point. Subfactors include the lack of a precision approach and no visual vertical guidance during low visibility or nighttime conditions. Therefore, the following standards could be incorporated into the operation's standard operating procedures:

• Approaches must be stabilized (speed, glidepath, and centerline) within 500 feet of the airport elevation or a go around is mandatory.
• Add 10 to 20 percent to all aircraft flight manual (AFM) specified landing distances.
• Permit no night approaches to runways shorter than 4,000 feet unless either electronic or visual vertical guidance is available.
• Make values from the AFM contaminated runway supplementary performance charts mandatory.
• Do not use any runway that has a crosswind component in excess of 20 knots or tailwind greater than 5 knots.

Similar standards should be developed for fuel reserves, severe weather, types of airports and facilities, nighttime operations, and duty and rest times for the pilot(s). In fact, most flight departments incorporate these additional standards into their flight operations manuals so that all department personnel know and follow their dictates. In doing so corporate turbojets employing professional two-person crews enjoy the lowest accident rate of any form of civil aviation. Unfortunately, business aviation, usually owner-operated, has an accident rate twice that of corporate aviation but still better than that for charter aircraft. Since many business aircraft operations are flown single-pilot the "two brains are better than one" concept may explain the additional risk.

Risky business

Once a baseline of flight characteristics and standards has been established, different potential flight hazards may be evaluated against the norm. For our purposes we'll assume that our King Air pilot's standard trip will encounter light instrument conditions on a daytime 600-nautical mile trip to a 6,000-foot runway served by an ILS. The table (see page 90) shows sample hazards that may introduce factors riskier than the norm. While the normal risk that we are willing to live with is categorized as medium or less, all of the unusual situations shown exceed that category, usually medium to high. Because of this each situation must be mitigated by some method to reduce the risk to an acceptable level, nominally medium.

For instance, your first flight into Aspen, Colorado, notorious for its high surrounding terrain and challenging instrument approaches, should include some training or at least a trip there with an experienced pilot to get the lay of the land. Similarly, although the instrument approach minimums at Aspen are already high, you may wish to consider raising them for both terrain clearance and missed approach considerations. And any takeoff must give special consideration to the possibility of an engine failure given the high terrain.

All of the other factors listed in the table illustrate ways of mitigating unusual or uncommon risks. Obviously, there are many more factors involved in completing a safe flight. Knowing when to apply a risk assessment and mitigation is an art form. Many pilots remark that if the flight feels different it probably is, and action should be taken accordingly.

If you are flying your turbine-powered aircraft as a single pilot, you should also look at the accident statistics for clues as to possible beneficial standards that may be added to your arsenal of safety-related standard operating procedures. Controlled flight into terrain comprises a major part of these accidents, especially descending below instrument approach minimums and impacting with rising terrain after canceling IFR for a visual approach; a significant number of these accidents happened at night. Therefore, either rigid adherence to instrument approach minimums or adding 100 or 200 feet to decision height/decision altitude or missed approach point minimums and a half-mile to the required visibility may reduce the risk associated with low instrument approaches. Similarly, never canceling IFR until on final with a clear view of the runway may minimize rising terrain encounters.

All of the factors mentioned are ones you would address before the flight. What about deteriorating weather conditions, unanticipated headwinds, and equipment malfunction? These are all-too-familiar surprises during flight and must be rapidly recognized as potential risks and attended to. The key is to recognize or, perhaps more accurately, sense evolving changes that may contain risk, and then act decisively and continuously until the risk is contained.

Risk management

While most of us have learned to intuitively calculate potential risks, many may not have learned to do so in a systemized manner that examines the severity/probability equation. More important, many may not have incorporated a structured form of evaluating and containing risk into their flying skills. That is what risk management is all about.

Recognition, assessment, and mitigation are the essential elements of risk management. But the ultimate form of risk aversion is not doing the action being contemplated. That is, just don't do it! Delay the takeoff or don't take off, avoid the weather system via a long detour, select a new alternate before arriving at the destination, or don't accept a poor setup for landing — go around and try it again.

Seek always to mitigate, but avoidance will usually let you sleep better after it's over.

John Sheehan is president of Professional Aviation Inc., which assists companies with air transportation analyses and flight departments with safety, management, and training issues. This article is based on a part of his new book, Business and Corporate Aviation Management, McGraw-Hill, New York. He holds an airline transport pilot certificate and an MBA degree.

Mitigating Unusual or Uncommon Risks