All materials have a thermal expansion coefficient that measures the minute change in size per degree of temperature change.
When the engines of our aircraft cool on shut down, the heat generated by combustion and friction dissipates at various rates based on the composition of the different materials. Cast iron and nickel based alloys change the least in size; aluminum the most.
These various metals bolted tightly together shrink as they lose heat, creating surface tension at the point they meet. When the amount of change overcomes the static friction a momentary slippage occurs between them.
It’s that shift we hear every time the engine ticks as the parts become unstuck from each other, change position and then stick together again.
The sound triggered vague thoughts that had been gnawing at the edge of my subconscious for months. After each flight I realized I had heard that sound before in a completely different context, that it was important to me, and I needed to remember where, and why and how.
I positioned the electric tug’s pincers over the nose wheel of the 182, clamped down with the lever and began easing the ship into the hangar. Dallas seemed longer than the five hours ago as I heard the boys in the shed near the museum holler out that the beer was cold. Not wanting to leave my buddy’s Piper unprotected, I let the big door come back down, left my aircraft outside and exchanged lies over Blue Ribbons for an hour.
The sound had continued as I walked away. It was gone when I came back, but the feelings that the sound evoked had stayed.
Trying to force the memory to the surface, others kept popping up, getting in the way.
Rolling in the snow with my six-year-old after his first big mountain ski day.
Sitting by the fire sipping bourbon as my new son-in-law regaled me with the stories of him and my daughter in London.
Feeling happy exhaustion after a day hiking with my too-long-absent son and his girlfriend at Rattlesnake Gulch near Boulder, Colorado.
Sailboats near the beach, sleds at the bottom, bride to the altar, toddler’s first steps.
What did all of these happy memories have to do with surface friction and thermal expansion?
I unlocked the man-door to the hangar, reached inside and turned on the light, punched the green UP button, and walked to the front of the plane.
As the big door slowly rose, light spilling out, I realized where I had heard that sound.
In high school, I was a band geek. I loved playing the trumpet with my fellow nerds. Creating a symphony with these friends and rivals and other similarly awkward teenagers, I felt a part of something bigger, something more than I could ever be by myself.
Our leader – Gladys Wright (no relation to the brothers) – would stand at the podium with her plastic baton and strike it against her metallic music stand as she implored, cajoled, embarrassed and teased us to our best musical selves by pointing out each sour note, poor tempo, and lapse in concentration.
We worked so hard.
We were good, too. Good enough to win an International Competition in Steenwijk, Holland my freshman year. Music was my refuge in high school; it was where I was happiest, most challenged and most accomplished.
When we were practicing during school hours and the band members were raucous and inattentive, Mrs. Wright would smack the stand in an urgent staccato to gain our attention.
But in the nervous excitement in the most important times before our biggest performances, just before the curtain opened, she held us all rapt by a measured and distinct tap that sounds exactly like the various metals of a Lycoming 0-540-D relaxing from its labors at different rates.
I pulled away from the airport and realized the connection: the sound of the engine ticking signaled the beginning of the most important time to my flying that’s not airborne.
I’ve come to know it as the after symphony.
After the winds have been tamed, after the distance traveled; after you have set aside the weather maps and navigational charts and flying’s fears. After you have arrived… it’s a moment so sublime, there is no other feeling like it. Joy and pride and relief and excitement drenched in the smell of hot oil and the sound of happy strangers and friends who know exactly how you feel – because they have felt it, too. It is the first movement of the symphony, brisk and lively, a sonata with you as the soloist accompanied by whoever is there to share the muse. When we are true to our self, we also hear the discordant note of sadness, that the excitement has ended and we have returned to our lesser earth-based selves.
As I stopped to pick up dinner, the strong theme emerged of tonight’s opus – it had been a joyous trip across the heartland from bright afternoon to golden dusk exposed and developed with a second darker theme in minor key – the witness of recent raw devastation by tornados in Oklahoma and Missouri. They had roamed my same air just two days before, and the images of the debris field became a foreboding, haunting second melody.
I turned these notes over again and again, recapitulating the larger images of beauty and serenity with the deep sadness including the deaths in an elementary school just 30 miles off my port wing.
After dinner and visiting with my wife, she retired while the song continued for me. The second movement is my time to slowly review the journey, to think of all the mistakes I had made and how I could avoid them the next time. I reviewed every single phase of flight and honed in on the dominant strains.
I sat back and thought deeply about my altitude decisions. I had started at 15,000 and, disappointed by the tail winds or lack thereof, had descended too soon in retrospect. While I still had an hour and 10 minutes of fuel at landing, I would have liked more and wondered what would have been the result had I stayed high.
I thought of lesser errors as well: the biggest was forgetting the autopilot was on Heading not Nav mode and drifting nearly a mile off course as I searched the downed trees and scattered mobile homes; the least was tuning a radio one digit off and immediately catching it myself when Springfield approach failed to answer.
I congratulated myself for good decisions in avoiding buildups, including requesting three waypoints to use a developing low pressure area to slingshot around Saint Louis instead of just asking for a few right and left deviations.
As I readied for bed, the lighthearted scherzo began. I thought of the lineman at Arlington (KGKY) who told me I had just missed a famous actor whose name I didn’t recognize. I had asked him for an encore from the fuel truck – my airplane is so hard to get full – and he found it funny that 2.5 extra gallons really did matter to me, even if he had to spill .1 gallons on the ground to get there. A five spot kept the smile on his face.
The ladies at the front desk told me the actor was Ty Burrell who plays Phil Dunphy on the ABC sitcom Modern Family. They said he was super nice in real life, “Just like you,” added the older woman who had checked me in on arrival. My gratitude included the special note that my adult daughter has said since the show’s pilot episode that I AM the real life Phil Dunphy. The kindness of the staff and their response to me reveal – “I don’t think that is a compliment!” they chortled – was a counterpointing fugue added to the movement.
I thought of the thorough preflight I had done, a slow trio shared with the lineman and his supervisor. As I touched each panel, checked each door, I ended with sounding the stall horn and bid adieu to the friendly ground-bound Texans and said hello to those above in the tower. A waltzing movement using a progressive taxi led to the thrilling takeoff capped by a “Ya’ll come back now” flourish to send me off to departure.
It is when I begin to fall asleep that the after symphony reaches its finale. It always begins with the joyous ode of overwhelming gratitude I have for the opportunity to pilot an aircraft, the realization that I am immensely happy and fulfilled in the air, that nothing could ever take the place of being in that left seat and that I can’t wait to get back there again.
This night it continued with a rollicking repetition of all I had before reviewed. The beauty and devastation; the strong and weak tones of my airmanship; the happy people who greet me away and at home.
It always ends with what I call the rondo of responsibility.
I am a good pilot.
I have a lot to learn.
I am a good pilot.
I will be better next time.
I am a good pilot.
I must always be vigilant.
I am a good pilot.
I will continue to read, to study, to practice and to remember that complacency is the enemy, the after symphony the ally.
I am a good pilot.
Mrs. Wright would be proud of me.
Three days later on a cold spring morning the process reverses.
The Cessna is pulled from the hangar and the engine instruments catalog the rapid temperature increase. I know under the cowling surface tension is being overcome at a rapid rate but its sound is inaudible among the cacophony. Now is not the time to play the music. It is time for the serious business of composition.
Frost covers the airport grass dusted by the slightest bit of granular snow that streams across the runway, driven by the northwest wind of a departed cold front. I am pleased taxiing south for a north departure turning west. This route will pass just to the right of my neighborhood and I will have a great view of my home.
Rich, the airport maintenance head, zooms across the ramp on his green ATV pick up attending to one of the multitude of details that make Clow International (1C5) as perfect as possible. We exchange gloved hand waves.
After liftoff the dawn has risen so the view is bathed in sunlight. I look down upon my street as the yellow school bus waits patiently for a child running on the sidewalk along Princess Lane. All around me the moisture in the trees and on the grass reflect the morning light and the refraction causes a billion pinpoints of brilliance to stream upward to meet my appreciative gaze. My net worth will never be more than a rounding error for the truly wealthy but this morning I am a king in a sea of diamonds.
So often the music writes itself.
A too short 70 minutes passes to find me on the ground at Grinnell, Iowa (KGGI). Over the radio the friendly voice of the lineman tells me to park at the self-serve. He already has the rental car running nearby.
“Just leave it at the pump, I’ll take care of it in a few minutes,” he says. “We’ll worry about the money later.”
Exiting the aircraft, I am alone, the engine clicking loudly as the chill meets the hot metal. Oil perfumes the air while I load the luggage into the car.
I absorb the stark beauty of the prairie, slowly turning a full 360. To the south the dull roar of Interstate 80 is a mile and a half away and I can see large trucks tracing the route. Just beyond is the purpose of the trip – my insurance company customer. Westward I know from experience the land is flat for miles and then slowly rises until interrupted by the majestic continental divide. Now I can see freshly plowed fields in that direction with tiny rows of struggling corn. North are the structures of the airport, the weather station, the beacon. Behind them I know is the quaint town with a jewel box and famous university, both surprising additions to what many would mistakenly consider the middle of nowhere. And east toward home the endless blue sky with smears of high white cirrus, an unspoken invitation to my anticipated return.
Locking the baggage and pilot doors, I take one last look before I head to the building for the restroom and more coffee. It is impossible to miss: the baton is lightly tapping the music stand.
Inside Ron Lowry and the duster boys are getting ready to spray. Their chorus of greetings – banal, bawdy, bantering at once – are the opening notes.
The next performance of the after symphony has begun.