Page 4 - Twin and Turbine December 16

2 • TWIN & TURBINE
DECEMBER 2016
editor’sbriefing
The Numbers Game
How good are you at playing the numbers game, when flying?
Like most pilots, you probably have some number-crunching aids to apply in common situations. You know, like so-many pounds of fuel for the first hour and so-many for each hour after, during cruise flight. Or, tripling the thousands to be lost
to get the distance required to make a crossing restriction. For a reciprocal heading or runway direction, add two hundred and take away twenty, or vice versa. We all have these little aids in our toolbox.
Making the numbers come out right is both useful and satisfying, but we have to be careful to stay on top of our game, or we’ll transpose and transgress. One of the worst offenders is mixing up altitudes and headings, like being cleared to fly “two- one-zero until reaching Flight Level one-eight-zero”, and then flipping the clearance to fly 180 to FL210. I even transposed a frequency and transponder code the other day.
When it comes to loading calculations, I like to round up to get things even; empty weight plus max fuel gives us 1,000 pounds for the cabin, plus a little cushion. That sort of thing. The problem is, I fly more than one airplane, and I can forget which one is heavier and which one is lighter. Numbers only work if you have the right numbers.
Nevertheless, I like to work the numbers, both to understand what the outcome of a given situation will be, and to verify what the computer is telling me. It’s important to keep your brain in the loop, rather than blindly accept a readout that can’t be logical. Back in the day of the E-6B whiz-wheel, it was common for students to reverse the miles and time rings and tell me it would take two hours to fly a 90-mile trip. “Now, does that make
sense?” I would respond, driving home, hopefully, the need to always verify results with common sense.
We’ve all probably had the experience of being handed off with an arrival vector that was obviously wrong, because we were going to a different airport than the one the controller had in mind. All the FMS and ATC computers in the world won’t keep us on the right track if the wrong data is entered at the beginning. GIGO (“garbage in, garbage out”) was the old programming admonition, and it’s still true. Computers are great at keeping track of numbers, and humans aren’t. But humans can analyze, based on experience and desired outcome, something computers lack.
That’s not to say we want to abandon the convenience of immediate arrival fuel-remaining readouts or automatic V-speed calculations. But with great capability comes greater responsibility; we can now get the wrong answer much faster, if we don’t watch the inputs. That’s why I’ll never give up the TLAR (That Looks About Right) method, which beats the WAG (Wildly-Applied Guess).
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When I joined Twin & Turbine Magazine as Editor five years ago, it was with the understanding that I would stand down if a more worthy replacement could someday be found. That day has arrived; after this issue, I’ll no longer be your editor. The good news is, we are fortunate to have former editor Dianne White coming back, effective with the January issue. Dianne knows the territory, from her past experience in this chair, and will be exactly what the magazine needs.
I leave with an accumulation of fond memories and a lot of friendships I hope to keep. Be careful out there.
LeRoy Cook