April 13, 2008

Back in Dallas

The wind can be your friend and the wind can be your enemy. On Friday during our transit back to Dallas, the wind was definitely not being friendly. No matter what I did, we had around a 15kt headwind the whole way up from Houston. It made for a long day especially since it was such a nice sunny day. Unfortunately in blimping a clear, sunny day isn't associated with the smoothest ride. As the sun heats the earth, the air warms and begins to rise forming what are called thermals. Since the airship has such a large surface area, even the smallest thermal keeps you busy on the controls as you try to maintain altitude and keep your pressure within limits. As the airship is pushed up by a thermal, the pressure in the envelope increases due to the expanding helium. So in the case of extremely strong thermals that can't simply be flown out of using pitch, the pilot may be pitching the nose full down, giving the engines full throttle, and pulling the air valve for the ballonet open. Luckily we didn't have too many thermals that were that strong. I think the worst was one that pushed us up about 500 feet in less than a minute. It still was a lot of work just keeping the ship level though most of the day. Needless to say, I slept well that night when we arrived at the hotel. It concluded my longest day at the controls since I began flying the blimp.