For the obvious reasons, I invariably get too busy to blog exactly when things get interesting...
 The Dynon D10-A display screen ... |
 ... installed in the MD-500 |
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The world’s most boring video clip |
As you recall, one of the difficulties we had to solvel when designing the vertical raceway for the games was the requirement to hover over a specific point while at high altitude. The problem is that while flying up high, the pilot cannot really judge the vehicle’s location or speed – imagine looking down from a jetliner (right about the time when you’re told to fold up your food tray and return your seat to the right up position) and seeing how everything down below is ant-sized… If you look downwards, every slight tilt of the plane, or every motion of your head, will result in very large apparent motion.
To solve this, our aviation consultant Keith Mackey worked with instrument maker Dynon to create a GPS based hover aid, which tells the pilot where he is situated relative to the desired hover point. The helicopter can be 5000 feet above and 5 feet to the left of the hover point, and the instrument will dutifully tell the pilot to move 5 foot to the left.
Having briefed the pilot on the instrument setup on Friday, the first task was to translate theory into practice. Understanding the instrument is one thing, but learning to fly it is another – the pilot has to train himself to properly react to the information the device is giving him – match the size and timing of the control inputs he’s making so as not to lag too much, nor over-compensate.
Luckily for us, Doug Uttecht, our pilot, is experienced in precision flying while pulling power lines, where he is constantly feeding off of instrument readings, and so was a perfect candidate for this job. Keith and Doug finished installing the GPS in the helicopter on Friday and we were all ready to go.
The first thing Keith did was take Doug for a test flight – in his car! They drove around the helipad, learning to operate the Dynon and getting a feel for the responsiveness of the GPS needle. (This was also significantly cheaper!)
They then took the helicopter on a 10’ hover, and replicated the car exercise, flying around the imaginary waypoint and watching the needle pointing at it and flipping around every time they passed over it. Then the same thing over again at 200 feet, where visual reference is still a viable way to hold position, except by then Doug was flying completely “heads in” – based solely on instruments. 2000 feet, no problem either.
Horizontal station keeping was typically within 10 m, and within 40 m on rare occasions. Vertical station keeping was similar. 20 minutes later they came back to the helipad, saying “well that was easy – what’s next?”
During the hover, Keith recorded this video of the instrument readouts. Boring indeed, since nothing is changing – as it should be.
Dynon have stepped up and are loaning us the instruments needed for the games, and we are very grateful for that – we could not have done this without them.