Whistling in the Dark

Sometimes because of my A&P certificate, I am asked for my opinion about the airworthiness of an aircraft. This happened recently when a young instructor asked me to look at a Schweizer 300 helicopter he was scheduled to fly with a student. He showed me what appeared to be cracks around the bolts that attach the struts to the tailboom. He wisely recognized that should this bolt lug fail, the boom would certainly leave the aircraft, and he would have a very bad (though short) day!

Sometimes in these situations, I have a level of comfort with the part or machine and thus, easily offer an opinion; other times, I just don’t know. Though I’m a certificated mechanic, I don’t have any real experience working on Schweizer helicopters. So my default mode in these situations is this: if I don’t know, I don’t go – and I advise my questioner (who obviously doesn’t know either, or he wouldn’t have asked) to stay on the ground until we do know. We can’t be killed by an aircraft we don’t fly.

“Not knowing” is a common place for humans to find themselves; in spite of our best efforts, we just can’t know everything. So what do we do when we face this "unknown" chasm before us?

First, we gather new information: we call the experts, perhaps the mechanic who worked on the aircraft last, the mechanic who regularly maintains it, the pilot who last flew it, or the owner who has a history with the machine. We also consult the FARs, the service manual, service bulletins, and other supporting data that might provide clues. In other words, we research the issue.

Only after this crucial step is honored do we get our hands dirty. The unwritten methodology in maintenance is to start with the simple and inexpensive and work toward the complex and expensive. This might involve ever-more extensive disassembly or throwing increasingly expensive parts at the problem.

Start with a careful inspection of the suspect part. This might just begin with your fingernail and a good light for a crack like the one we had. Get a bright flashlight, though -- and a mirror, if necessary. Lighting is critical here; a dark hangar won’t do, and surprisingly, a brightly-lit ramp might be just as bad because it’s often too bright and offers no contrast. A simple magnifying glass is often the perfect tool, or you might need some NDT (non-destructive testing) methodology like dye penetrant to “get deeper” into the problem. If that doesn’t solve the uncertainty to your satisfaction, you might have to remove more parts, inspection panels, or cowlings; paint might have to be stripped.

After a cursory inspection of the cracks, several phone calls were made. The mechanic who regularly cares for the machine offered to come look at it. After carefully inspecting it, he assured us that the paint was cracked because there are rubber shock grommets around the boom’s attach bolts, and they had been painted over some months ago; needless to say, the natural action of those grommets easily cracked the paint over time. So, what appeared to be potentially life-threatening cracks turned out to be “normal” and the little helicopter was good for flight.

But how would you know unless you asked? We simply don’t know what we don’t know. Would it have been worth it to fly the aircraft…and just hope that it was OK? I call that "whistling in the dark…."

Fly Artfully!

What Awareness?

Last weekend, I observed a pilot start his Bonanza at the fuel pumps after topping off. When the engine lit, the throttle was probably set to around 2000 RPMs. The resulting prop blast rocked the open-doored Cessna 172 behind him -- and its unlucky pilot, who was standing in front of his aircraft, waiting his turn for fuel.

The week before, I watched as the pilot of an RV-7 started his engine in front of the FBO, initially blasting away at 15-1800 RPMs. Behind him, an open-doored (and untied) Luscombe began to move. But if that wasn't enough, this thoughtless pilot then turned 90 degrees (with much power), blew the hats off a group of newly-made enemies standing in front of the terminal building, and directed his prop blast into the open door of the FBO. Papers flew everywhere.

A friend who runs a maintenance shop on this same field told me that pilots start their airplanes up in front of his open hangar door all the time, blowing cowlings, tool chests, dust, fine gravel, and loose parts across the floor of his shop.

Where is the awareness in these pilots? If they are this thoughtless on the ground, I have to wonder how aware they are in flight.

Here are a few reminders of ways we can operate our air-machines with more awareness -- and to avoid making new enemies around the airport:

Before starting, it takes only a few seconds to take a look behind your aircraft to see what might be blown away by your prop blast. Do this before getting into your machine. You might decide to move your aircraft away from people or things that could be displaced or damaged after you start. If you are in a line of tiedowns with other aircraft tailed toward your own, pull your aircraft out of the tiedown spot and turn it 90 degrees to the row. This prevents damage to the flight controls of the aircraft tailed towards you.

Also, be aware of the slope that the airplane is parked on. If it's pointed uphill, you might consider moving it slightly downhill or at least to level ground so that you will be able to begin taxiing with less power.

Before starting, make a final check behind your aircraft. When you yell "Clear!", use that as a reminder to not only look around your propeller(s), but behind the aircraft, as well.

An engine wears considerably more without oil pressure (the time right after the engine starts). So try to start the engine at the lowest possible RPM, and run it there until all the internal parts are properly bathed in oil. This only takes a few minutes.

When you are ready to taxi, again check behind your aircraft for changes, especially pedestrians that might be passing behind your tail. Then smoothly throttle up...and wait. Give the aircraft a few seconds to move before adding more throttle (and prop blast). There are no awards for a fast getaway.

Next time you fly, think about that maelstrom you’re unleashing before you push that little black knob forward. One of the sure signs of an Artful Pilot is awareness, and your care and attention during ground operations are sure signs that someone in the cockpit is awake.

Fly Artfully!