Know Your Systems

    By: Alex Burton

    CFI Principal Air Ltd. Chilliwack B.C.

“By three methods we may learn wisdom: First, by reflection, which is noblest; second, by imitation, which is easiest; and third by experience, which is the bitterest.”
--Confucius—

    I was discussing emergency procedures some time back with a person I interact with on a regular basis. He related an interesting story. He was flying one day and, glancing down for an instrument check, noticed decreasing airspeed. Being a methodical, careful, alert pilot, he checked his other instruments to see if more information would reveal the problem. RPM appeared stable as did altitude, attitude, and vertical speed. Oil temperatures and pressures remained in the green…. a puzzle.

    The truth, of course, emerged. First by smell, then by the appearance of smoke from under the dash, an electrical fire revealed itself. Heated wires had burned a small hole in the pitot tube input to the airspeed indicator, reducing pressure and manifesting as an apparent reduction in airspeed.

    Electrical malfunction would not have been my first thought given the early symptom of airspeed loss nor was it his initial diagnosis. He did recognize he had a problem, however, and was alert for emerging symptoms as they revealed themselves. He was prepared for the situation when it did, finally, make itself clear.

    Sadly, emergencies do not always telegraph themselves as clearly as we might hope; a voice does not sound in our headset saying “Electrical Fire. Follow the Procedures in Your Emergency Checklist for Electrical Fire.”

    It would be nice if that did happen; it does not.

    I notice a variation on this theme fairly regularly on flight tests. Students have worked hard to memorize the procedures on their emergency checklists and are normally prepared to recite them accurately and at a high rate of speed. However, unless they are given a very clear statement of the “emergency”, for example, “You have an engine fire,” they may have difficulties deciding which emergency procedure to employ.

    I’ll give a specific example. Let’s say I am flying with a pilot candidate and we are in an extended climb. I might say something along the lines of “We’re in a long climb. Let’s say it’s a very warm day outside. Checking the oil temperature gauge, we notice it is pointing to the very top of the green or even slightly above. What should we do?”

    I’ve received a variety of answers from shut the engine down and conduct a forced landing to level off, enrich the mixture, and reduce power.

    During de-briefing following the flight, I’ve worked with the candidate to analyze the situation. What are some of the factors that might cause high oil temperature to occur? What information can we get from the other available instruments? What is the potential difficulty we are facing? What are the potential remedies available to us? What might be a reasonable remedial action? What would we expect to happen? What if what we expect to happen doesn’t happen? What might be another line of approach?

    Virtually every decision we make, both in flying and in life, is made with partial information and limited time. We simply do not have complete information available to us at any given moment, nor, normally, do we have all the time and leisure available to fully investigate all aspects of a problem prior to making a decision. We can, however, mitigate our limitations by ensuring we have made a good effort to know and understand what we are dealing with before we find ourselves in difficulties.

    Time spent on the ground learning our aircraft’s systems is time very well spent. Knowing how each system works, what its component parts are, where they are, and how they function can give us considerable insight into situations that may develop. We’ve all heard or read about the fellow who executed a forced landing due to fuel starvation when he still had 35 gallons of fuel in the “other” tank.

    Many pilots will remember the acronym DECIDE from their training: Detect a change. Estimate the significance of the change. Choose the outcome objective. Identify plausible action options. Do the best action. Evaluate the progress.

A slightly simpler four-step, circular model, as presented in Transport Canada’s Human Factors for Aviation Basic Handbook, TP12863 (E), is:

1. Gather Information

2. Process Information

3. Make Decisions

4. Act on Decisions

    Problem-solving is a dynamic, ongoing process dependant on a number of factors including awareness of the situation, knowledge and understanding of available options, an ability to isolate and identify symptoms, a willingness to make the best decision possible given what is known at a particular moment, and the ability to evaluate the results of those actions and apply the results of our evaluation toward further action, as required.

    Knowledge and understanding are invaluable tools. It is a good thing to memorize your emergency checklists. Please do that and keep the checklists handy, as well. It is not, however, the end of the process.

    Emergencies do not always arrive clearly labelled. Understanding, as you might say, the etiology or origins and meanings of symptoms can increase our ability to work more quickly to the essential problem manifesting itself and its potential remedies.

    Learning an aircraft’s systems, knowing and understanding how they work and what might happen if they only partially function or fail to function entirely, can be a very important addition to our ability to conduct safe flight for ourselves, our passengers and all those others who wander the roads and paths below looking up hoping we will not drop out of the sky on their heads.