What you can’t see can’t touch you

Flight instructors carry those little soap suction cups around in their flight bags like prized currency; I know I always did when I instructed. They were invaluable tools; and we all know what they’re used for. Most students despise the very sight of them, too, because their emergence means partial-panel work is next. And if a student is savvy enough to sneak a quick glance at his instructor at that particular moment he might catch a menacing, evil sneer on the teacher’s face – in jest of course; all instructors well understand that not many of us enjoy partial-panel flying.

Failed attitude indicator
Who can you trust?

But how many of us continue to carry these pliable and unlikely instruments of torture after we’re through instructing others in the art of flying? There was one time in particular that I was very glad I had two of them.

I was flying the daily mail run in a saddle-worn Cessna 402 out of Abingdon, Virginia, through Roanoke and Lynchburg, and then on to Richmond on a very cloudy, turbulent, rainy, miserable night in mid-March. We had just leveled out at 5000 feet and ten miles west of Goose intersection headed east to the Lynchburg VOR when the radar approach controller in Roanoke called to inform me that I appeared to be turning toward the north. He asked if that were the case, and if so, why.

I replied, “No, I am straight and level on a current heading of 085 degrees, and I show I am just left of course.” He deferred, saying that I was slightly north of course, but continuing to increase my divergence from the airway. So, at that moment my ears were telling me that something was wrong, but my eyes countered the suggestion – saying all was well. As a result, my brain decided to put my stomach on a red alert and prepare for the great purge. And I hate that feeling…

In just a few moments I began to see the VOR needle start creeping its way to the right – a sure indication that I was indeed turning northward – even though my instruments continued to show that we were still straight and level. A quick glance at the magnetic compass confirmed the fact that we were, sure enough, in a left turn. Right about then the airplane began a gradual descent, but the attitude indicator continued to deceive me by showing a straight and level flight condition. This was crazy, and initially anyway, I was very confused.

Failed instrument cover
We all use them in training, but do you keep them around after the checkride?

There are many philosophies that can be pondered at a time such as this, I suppose, but there is precious little time to do so. To make a long story short, I was dumbfounded to realize that I was experiencing a vacuum failure, and that both my attitude gyro and heading gyro were calling it quits for the night. I was actually in the initial stages of an emergency situation. Where were the warning bells, where were the red flags? I thought to myself: “How insidious and cowardly this scenario is. I’m losing everything, and nothing is doing anything in spite of it.”

I like to think that because of my training and experience as a flight instructor I was able to keep calm and think fairly quickly. I simply reached into my flight case on the seat next to me and retrieved two of those blessed fifty-cent suction cups. Quick as a wink, I put out of sight the two offending traitors that were, in concert, leading me to certain doom. With my mind fully engaged in a “damage-control” mindset, I settled down to some serious partial-panel flying and informed the audibly-anxious controller that I would just continue on to Richmond where the weather was VFR.

Of all the emotions I could have displayed that night, the one I defaulted to was anger. With a few choice words and phrases I let the vacuum pump and the company management know I was very displeased at their lack of commitment to duty and personnel. But I also realized that gyro failures in instrument conditions, while dangerous, are not to be allowed to control us; we are there to control them. When you are the pilot-in-command, command. Let the machine know you have dominion over it; not the other way around.

9 Comments

  • Having a few of these in the glove box can’t hurt, I’m ordering some tonight. Thanks Dave 🙂

  • Bad information can be much worse than no information. The lesson in this article applies to navigation as well. Inertial nav systems used to drift. Beyond a certain point it was better to dim them completely.

  • Am curious about the failure mode. Aren’t there two pumps on a 402? Was there a latent failure of a check valve?

    • Stephen, I’d have to go back and check on the 402 systems to answer that question. This event took place 33 years ago, and I haven’t flown any 402 since 1993. Even so, the “company” of which I refer was never known for impeccable maintenance – if you catch my drift. No tellin’ what was wrong with it at the time.

  • I still carry in my flight bag the 4 Sporty’s suction cups I bought 35 or so years ago. I used them while I was instructing but haven’t had the occasion to use them since then (knock on wood). But I figure that someday I might need them. You’ve substantiated that possibility.

    Cary

    • Cary,

      Yes, gyros and vacuum systems are marvelous inventions and tools to have at our disposal, but they do have their Achilles heels. I’ve had several gyro-system failures over the years – mostly in Cessna 207s – strangely enough; go figure…. It’s always a good rule of thumb to keep that magnetic compass included in your regular scan pattern if you’re in the soup. Happy flying.

  • Thanks for the great article. I’ve always been concerned about recognizing a gyro failure. I’m hoping that the Garmin portable GPS I have mounted right in front of me will help when the track starts to swing.

    • Don,

      I’ve never been able to completely relax while flying – IFR or VFR – and I like to think that being alert helped me spot the problem so quickly. However, it was the controller who first brought my attention to something being amiss. I wonder how much longer it would have taken me to see the inconsistency in my instrument readings if I had not been in radio contact with him…. I don’t know. Nonetheless, I remain diligent in my scan. Thanks for the comment, Don. Happy flying to you and yours.

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