Archive for the 'aviation' Category

Flying with the Angels

August 1, 2007

Today, as before, I ran through the 10-minute checklist and engine start sequence, felt the tiny R-22 rock from side to side, then smooth out, as the blades spun up and went “whupwhupwhupwhup.” I checked the cylinder head temperature, carburetor heat, sprag clutch (rotor freewheel), the dual redundant magnetos, and the low-RPM alarm. The 900lbs R-22 should be called the Kent Beck Special; it’s the simplest helicopter that could possibly work. There are bicycles with more technology on them, and one that weighs almost as much.

Then my instructor hovered us above the “H” pad while we waited for Boeing Tower to clear us for take off. After 10 hours of instruction, I do most of the flight maneuvers but I’m not ready to hover near a busy runway. Hovering is like balancing a unicycle in three dimensions while random wind gusts try to push you over.

This doesn’t stop my instructor “Mike” from pushing me to try. I’ve never seen Mike break a sweat. He even stayed cool two weeks ago when I dropped us toward the ground in a flat spin and he had to pull collective hard enough to trigger the low-RPM alarm a few feet above the grass.

As I took off and pushed the cyclic forward through translational lift (~50 knots airspeed) I overheard Boeing Tower advise another aircraft “You’ll be following the F-18.” Sure enough, below us and to our right we saw a Blue Angels F-18 on final, wheels down. I never thought I’d see one of them from above, let alone as a fellow pilot. (I recently realized a student pilot is a kind of pilot!)

Today was windy, and tougher than last time. Hovering ten feet above someone’s farm, Mike asked me to do a 360 pedal turn. Nothing happened at first due to “weathervaning” from the wind. I gave it more pedal, and suddenly the wind whipped us around before I could catch it with the opposite pedal. Learning to fly requires learning to respect the wind. The pedals are backward from what you’d naturally expect, an ergonomic mistake from 1940 that will probably never be corrected. The trick to flying a helicopter is to give a lot of small corrections before you’re consciously aware they’re necessary. Any big movement will throw everything out of whack.

Later on Mike told me to fly up to 1000 feet so he could show me autorotation, an emergency procedure every student must learn before soloing. Having just learned more people are hurt during practice autorotations than in actual engine failures, I didn’t really feel like trying this. If rotor RPM goes outside a narrow range, you crash.

Mike throttled the engine down to idle and pulled us into a nose-high attitude. The cabin went silent with the engine almost off. I watched in horror as the engine/rotor RPM gauges split, as if the machine’s heart had stopped beating. I kept breathing deeply as my own heart’s RPM went off the scale. As we fell, the wind noise picked up and the rotor RPM increased. We were now a wind-powered gyrocopter with a glide ratio slightly better than a brick. Mike calmly demonstrated how all the flight controls still worked due to the wind pushing the rotorblades around. I realized the first autorotation of my life was probably Mike’s second or third of the day.

As the ground raced up toward us, Mike flared the cyclic and then the collective, exclaiming “Look! We can still hover!” And we did, for a few seconds. Then the rotor RPM fell into the yellow zone and we cranked the engine for a powered recovery a couple feet above the ground.

Someone said “Never drive faster than your angels can fly.” On my K-bike I have confirmed my angels can fly at least 140mph. But can they hover?

–mj

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