Warning: ob_start(): non-static method anchor_utils::ob_filter() should not be called statically in /home/kradmin/public_html/wp-content/plugins/auto-thickbox/anchor-utils/anchor-utils.php on line 33

Warning: ob_start(): non-static method sem_seo::ob_google_filter() should not be called statically in /home/kradmin/public_html/wp-content/plugins/sem-seo/sem-seo.php on line 540

Margins

It was a very dark, moonless night at Paso Robles, California when my wife Janet, our friend Lena, and I finished a lovely dinner and were boarding the airplane for our flight home. Paso Robles is in a valley, surrounded by high terrain, and there would be very few signs of human habitation along most of our route back to the San Francisco bay area. Anticipating this, I had filed an IFR flight plan and prepared to fly the published obstacle departure procedure to give us an extra margin of safety.

Let's face it—one of the main challenges to confidence, and one of the main reasons we need it, is fear for our own safety. Some very skilled and experienced pilots have quit flying because this fear finally became too strong to suppress. They might have been flying for years on hope and denial, but finally the fear that they were living on "borrowed time" got to them and they hung it up. Astronaut Mike Mullane in his riveting book Riding Rockets describes this as a common phenomenon in the astronaut corps, and it's not surprising. Space travel is a very risky business.

Fortunately, most of the flying we do is much less dangerous. A circuit around the patch in a Cessna 150 is quite a different proposition from riding a rocket into space, but there's no denying that taking any machine into the air necessarily involves some risk. How we manage and mitigate that risk is a big contributor to our level of confidence and its appropriateness.

One way to estimate risk in a given situation is to consider what margins of safety are available. In another great astronaut book, Carrying the Fire, Mike Collins describes in some detail how the Apollo spacecraft were designed and the astronauts trained with meticulous attention to margins of safety. Redundant systems and exacting procedures helped minimize and mitigate huge risks. The emergency aboard Apollo 13 that threatened the lives of the crew ultimately proved the value of this strategy, as the crew was able to use the versatile systems in ways never before anticipated, such as using the lunar module as a lifeboat and adapting incompatible CO2 filters from one system to another.

The aircraft we fly are also designed with built-in margins of safety, including redundant systems (magnetos, radios, backup instruments) and structures designed to handle greater stress than required for normal flying. All that's needed for us to take advantage of these margins is the right training and practice. If we know our aircraft's maneuvering speed at its current weight, we can stay within the safety envelope when flying in turbulence. If we're practiced in partial-panel instrument flying, we can keep straight and level when the attitude indicator goes belly up.

Safety margins are integral to our flying in countless ways, including weather margins, flight and fuel planning, traffic separation, and instrument procedure design to name a few. All these margins legitimately boost our confidence in our pursuit of this endlessly fascinating craft of flying.

Some of our greatest safety margins are provided by other people, including mechanics, controllers, passengers, and FBO personnel. In fact, these human-powered margins of safety might be the most valuable of all. More about that next time.

As we approached the city lights of the Bay Area, the black, featureless landscape and sky gave way to familiar landmarks and a clear horizon. The controller sounded harried as he worked to sequence us with the big boys approaching San Jose International, so I took pity on him and canceled IFR.

"377, contact San Jose tower on 124.0. Thanks for your help—g'day," replied the grateful controller, and we finished the flight VFR. The IFR flight plan wasn't required that night, but the extra margin of safety made for a little more peace of mind—and that's always good for a pilot's confidence.

Post a comment

Leave a Comment

Comments are queued and moderated daily.

Fields marked by an asterisk (*) are required.

Register Login