Saturday, November 29, 2008

To Knoxville, Thankfully

We have a lot to be thankful for. We are both healthy, we have been relatively successful in our careers, and we have good families who are also healthy. We also happen to have an airplane and the license to use it to visit family on holidays, which is what we wanted to do this Thanksgiving. Our tentative plan was to fly to Knoxville on Tuesday to be with Jodie's family and attend a fundraiser gala for the local children's hospital. The weather was horrible on Tuesday, though, so we postponed our trip to Wednesday and enjoyed Tuesday evening to ourselves.
DEPARTURE

The weather on Wednesday was better. There was a strong wind from the southwest that was blowing the bad weather away to the northeast. The first 150 miles, however, had pretty low clouds. We launched around 1 p.m., under overcast skies and headed west. Crossing the first mountain range, we headed south down the Shenandoah Valley.


The clouds were sitting atop the mountain ridges on either side of our route, so we stayed in the valley, just a couple thousand feet off the farm fields below.


There was an occasional bump of light turbulence, so we cinched our seatbelts tight and I kept our airspeed a bit slower than I normally would have. Then, southwest of Charlottesville, breaks in the clouds began to appear. It was really beautiful.



Jodie flew the plane for a while as the overcast layer split into patches of clouds and we climbed above the higher mountain ridges of southwestern Virginia.


As we passed southwest of Fredericksburg, Virginia, the clouds dissolved completely and we began climbing to 8,500 feet. There was an AIRMET for turbulence below 7,000 feet, and the winds aloft were forecast to be as strong as 50 knots. Wind that strong can create strong turbulence and, in some circumstances, mountain waves, so I wanted to be as high as possible above the higher mountain ridges that were ahead. As most of them did not exceed 4,500 feet, I judged that 8, 500 feet would be sufficient.

Although the headwind was slowing us by 20-30 knots, the air seemed to smooth out as we climbed through 4,500 feet. We began relaxing and enjoying the view as we cruise-climbed toward 8,500 feet. Then, without warning, as we passed through 7,000 feet, it felt like a huge hand came down on the plane. Apologies to Richard Bach: the image of the hand hitting the airplane is borrowed from his description of flying a biplane through turbulence in the Sierra Nevada Mountains in his book, Biplane. It is perfectly appropriate, though, and immediately came to mind when this happened. I hit my head on the ceiling despite my tight seatbelt, the stall warning horn wailed, the nose dropped, and the plane tipped onto its left wing. Kudos to my flight instructors -- my reactions were instant and instinctual, and the plane was level and flying again within a second. From there on out, the ride was silky smooth. And Jodie barely blinked an eye.


Jodie fell asleep as we passed over the snow-covered higher elevations of southwest Virginia. Our true airspeed was about 135 knots, but our groundspeed varied between 95 and 115 knots because of the headwind.

Then we began losing altitude. Although nothing had changed in the airplane's configuration, the plane began a descent of 500 to 1,000 feet per minute. I raised the nose, but we continued down. I put in full power and raised the nose some more, slowing the plane to "Vy," its best rate of climb airspeed. The rate of descent slowed to about 100 feet per minute, but that was the best it would do. I suspected a mountain wave, but I wasn't sure. The engine was showing 2,400 rpm. Was that normal? It seemed low for that altitude, but I had never paid close attention to the rpm during a climb. And we were high, so the engine could not make full power.... I didn't think it was unusually low, and all other gauges were normal.

I still suspected a mountain wave, but I was not certain. I enrichened the air/fuel mixture: no change, and we continued down. I leaned the mixture: no change, and down we went. Pulaski airport was about 22 miles away, and I adjusted our course toward the airport, debating with myself whether I should turn further east toward Roanoke. Roanoke was closer, only 15 miles, but there were mountain ridges to cross, whereas there was only valley between me and Pulaski. I was confident I could make it to Pulaski if we continued descending, but wasn't certain we could clear the ridges on the way to Roanoke. With the nose raised, trying to climb, our groundspeed was about 65 knots (75 mph), agonizingly slow.

We were now down to 7,000 feet. I still suspected a mountain wave. All indications were that the engine was fine. There was no ice, nothing that would provide a mechanical explanation for the airplane being unable to hold its altitude. The altitude held at 7,000 for a bit, then fell to 6,800 as we struggled toward Pulaski.

Then, just as suddenly as it had begun descending, the Tiger started climbing, slowly at first, then at 1,000 feet per minute, its normal Vy climb rate. A couple minutes later, we were again level at 8,500 feet and back to our usual speed. Mountain wave? I wondered. Then I heard a jet pilot talking to air traffic control. "I just went through a heck of a downdraft," he said with a southern drawl. I nodded knowingly. I waited to see if the mountain wave would repeat itself, but we never again had trouble maintaining our altitude.


Jodie woke up as we crossed into Tennessee and began picking out geographical features -- rivers, the Clinch Mountains. Then Cherokee Lake came into view and we followed the Holston River to the airport, with the Great Smoky Mountains off our left wing.


Overall, the plane worked out great for the trip to Knoxville. Other than our experience with the Giant Hand, the ride had been comfortable. Although our 10 minute ride on the mountain wave had got my attention, it had been smooth and both Jodie and Millie slept through it. And even with the strong headwind, the trip took only 3 hours, 35 minutes, far less than the 8-9 hours it takes to drive.


THE RETURN

We had a wonderful holiday with family and friends. Instead of shopping on Black Friday, Jodie and I spent the afternoon at the Downtown Island airport in Knoxville. I met someone who also owns a Tiger and who had, until now, been just a name on an email. As we talked, Jodie's cousin arrived with his wife and airplane-crazy boy, Nicholas. Before the day had ended, all three had been for a flight around Knoxville in the Tiger, but I'll write a bit about that separately.

As Friday drew to a close, it was time to plan our return. Saturday looked to be okay in the early morning, but heavy rains and wind were forecast to arrive from the south sometime before noon. Jodie and I decided to pack the plane and shoot for a 7 a.m. departure. We lifted off minutes after sunrise, at 7:38, into overcast skies and circled west over downtown Knoxville before turning northeast for home.



As we headed north, the cloud cover began breaking up. It was another beautiful flight.


I had been hoping for a tailwind to at least equal the headwind we had had on the way south, but the wind only gave us a 5- to 10-knot push. Jodie flew while I enjoyed the thermos of coffee that her father had prepared for us, then she leaned over and napped while I flew on through smooth and clearing skies.



By the time we crossed the relatively barren and isolated mountains of the Ramseys Draft Wilderness, there was not a cloud anywhere to be seen and the visibility was at least 50 miles. There was neither turbulence nor mountain wave activity, and it was a treat to look down on the folds of the mountains below.


It wasn't long before we were passing White's Ferry over the Potomac River and approaching the airport at Gaithersburg. Just under three hours after liftoff, our tires chirped as they contacted the runway.


We had lunch at the airport cafe, then unloaded the airplane and headed home, picking up our cat at the kennel on the way. Later in the afternoon, after a nap, I decided to look at the weather to see what we had missed. I guess we have one more thing to be thankful for....

1 Comments:

Blogger Amy said...

That is an awesome shot of Jodie sleeping. Good job on blogging tale too. Oh, and the turbulence recovery. :-)

5:01 PM  

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