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Aviation Safety

AVIATION SAFETY

Dave Fry, WVFC CFI and Aviation Safety Counselor dgfry@aol.com

 

The Scoreboard

Back in what today seems to be the dark ages, I used to play basketball.  I’m using a couple of terms rather loosely there, as I was far more energetic than good.  Our team’s default strategy was that because I could out jump everyone else on the court, I jumped center for the tip off, and would then drop back to my normal guard position for the rest of the game.  It would frequently develop that I would also get the first shot for our team – a (no surprise) jumper, in which I’d be well over the defender.  That also got me on the scoreboard – usually for the only time in the game.  But it was always nice to check the scoreboard to see that we were actually on it.  Even if it didn’t show what our team wanted, it showed what was actually going on in the game.

There is a line on the G1000 and on many other Primary Flight Displays called by some, the scoreboard.  It’s the line that will tell you what the Flight Director (and therefore, the autopilot if it’s engaged) is doing.  Invariably, the thing that gets pilots into trouble when using an autopilot is when the pilot thinks the plane is doing one thing and the autopilot thinks the plane is doing another.  I may have been in that position once or twice (or more) in the past.

So, how does a pilot and an autopilot get out of sync?  I suppose there is a large number of ways in which it’s possible, but the fundamental is that the pilot takes some action with the autopilot controller and neglects to check what’s on the scoreboard.  Pro pilots deliberately look at the scoreboard immediately after taking an action on the autopilot controller.  Some watch the scoreboard as they take the autopilot action.  In either case, they have immediate feedback that the autopilot actually thinks it’s doing the same thing they think it’s doing.

That (in addition to the smoke) was my most recent indication of an autopilot problem.  I had pressed the Yaw Damper in a Pilatus but the YD indication didn’t appear on the scoreboard, so I pressed it again, at which point the autopilot flunked the smoke test.  Had I not watched the scoreboard, I might not have noticed the issue until after we got into the clouds, in which case things might have gotten more interesting than they actually did.

However, many of the club planes don’t have G1000s or any other kind of primary flight display.  So how does this concept apply to them?  Glad you asked.  Virtually every switch, knob or button on any airplane has a corresponding light, gauge, or other indication associated with it.  For example, when you put the flap lever down, the indicator shows the flap position and you can see whether the flaps actually moved as you selected.  Assuming you can’t see the flaps themselves.  And I’ve had that one happen, too.  I was flying with a student, who after a simulated engine failure, initiated a go-around including raising the flaps.  Well, she raised the flap handle, but neither the flap indicator nor the flaps moved.  Her first indication that something was amiss came when she noticed that it’s nearly impossible to climb in a 152.

The next time you’re in your favorite club (or other) plane give it a try.  Every time you push a button, flip a switch, turn a knob or push a lever, see if you can find an indicator that shows what you’ve done.  Then, every time in the future that you take those actions, look at the indicator to make certain that what you want is what you got.

Treat the plane like a science experiment – take an action, verify the results.

Get on the scoreboard.

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