Friday, July 10, 2009

aviation technology and the human role in it

This report on a near accident on China Airlines Flight 006 in 1985 is a fascinating read in terms of the aviation details combined with aspects of human factors engineering. As pilots (and people in general) become relegated to monitoring roles when technology takes over many activities, the results can be unpredictable when the unexpected happens. The section labeled "2.2 Flightcrew" contains some very interesting observations along that line.
My recent flight to KCHO had an event that made me think of this. I had the autopilot fly the GPS Y RWY 21 approach (to start learning how to do it), as we reached the minimum (1,400 ft), I set it to fly the missed approach and it began the climb to 4,000 ft at 500 fpm. It seemed to pitch unusually high and airspeed started dropping way off. Everything worked fine but afterwards it made me wonder how long it would have taken me to decide to take over if we had been in danger of a stall.

Sunday, July 5, 2009

instrument training flight (first GPS approach)


It's been a little over a month since my last flight (in a Citabria) and I had a little time yesterday so I decided to do another instrument training flight and get some XC time (cross country). We took a 172 with a KLN-94 GPS and KMD 550 MFD. We flew from KJYO (Leesburg, Va) and took the GPS Y 21 approach into KCHO (Charlottesville, Va). This was my first GPS approach and we had the autopilot fly it which was pretty neat. I'm used to flying VFR straight in to runway 21 but the GPS approach had us hold at the WITTO intersection and then angle in via the ECEUS and MUSOJ intersections so you actually come in at an angle to miss the little hill on the left before the runway. One thing that I'm beginning to realize is that if you are in actual instrument conditions (meaning you can't see very far), if you see the runway environment when you reach the minimum altitude you are going to be very close to the airport and you will probably have to drop your flaps right away, slow down and descend quickly to land. I can understand how stressful instrument flying can be.
From there we went up the CLADD intersection and took the ILS 32 approach into KOKV (Winchester).
After KOKV we headed back to KJYO and were done for the day.
I did notice one thing about flying using the autopilot. It's easy to stop paying attention and just mess with the GPS or just look around and forget simple things like throttle back when you reach your cruise altitude because the autopilot is doing most of that for you (I was trying the autopilot fixed rate of climb coupled with the altitude arm mode meaning it would climb at a particular rate and then level off automatically at a set altitude).
All in all it was another fun and learning filled day.
My totals so far are:

landselxcnight
250126.628.611.4