Test flights are underway! So far we’ve completed two flights out of NCAR Research Aviation Facility in Colorado. We’ve headed out both times over Wyoming and Nebraska because there is less air traffic there so we can change altitude more freely and try different maneuvers to test how the instruments on board cope. We got some interesting view of bluffs dusted with snow and such wide open spaces!
We reach higher altitudes on these flights than I’ve done before, and that is a new challenge for my instruments. I noticed some flow issue on the first flight, which were improved slightly with recoding some of my instrument control programs, but performance still wasn’t optimal today, so I’m going to have to rethink the some of the flow and pressure control in the instrument before the main flights in July.
The other issue I’ve noticed is a small leak in one of the instruments. Things like this become more apparent in flight because the instrument is at the same pressure as the outside air (so on today’s flight that was about 150 mbar), but the cabin where the instrument sits is closer to ground pressure (around 1000 mbar), so any leak will suck air from the cabin into the instrument. I took the affected instrument off briefly after the flight and took it apart to see if I could fix the leak. Annoyingly, it’s deep in the optics (the most complex and delicate part of the instrument! Of course!) and so will be a longer job back in the lab once we de-install from these test flights. Thankfully, the leak is very small and, for the purposes of test flights, I can carry on with it there. The data quality wouldn’t be good for science, but we’re really testing the engineering of the instruments and how they interact with the plane here, so I can still get useful information.
I was mission scientist for the first time today. The mission scientist is a designated scientist on board the plane (there were 6 of us today) who acts as the primary contact between the scientists, mission control (a crew member who is in charge of how everything is running in the back of the plane), and the pilots. She or he makes in-flight calls on route, maneuvers etc. reacting to the needs of the scientists on board, and the constraints set by flight conditions, fuel and commands from air-traffic control as relayed by the pilots. With smaller science crews like we had today, and only testing rather than science requirements, the job was pretty straight forwards. On science flights, when the flight may be the one chance to get the data you need, and multiple mission objectives may come into play, it can get quite complex.
