This afternoon I did a flight from Morristown NJ to Sikorsky Airport in CT, and was assigned the RNV approach to runway 29 at KBDR. I was descending on the G/S, and switched off the AP at around 1000 agl, all of a sudden near 600 feet, the nose swung wildly to the left about 20-30 degrees, and I started losing altitude and airspeed, both at the same time. Prior to this I had the aircraft in trim at 75 mph with full flaps, in a very stable approach. When the first happened I thought it was one of those control failures in the Cherokee, but all controls were working properly. I applied full power, flaps to 20, and just barely avoided crashing onto the taxiway by about 20 feet. I then decided to just climb to pattern altitude and fly the approach VFR to the same runway. I flew a normal traffic pattern at 1000 agl, and lined up again on the runway, and at about 600 feet the exact same thing happened again, but this time I came in a bit fast and high, and was able to land on the runway with about 2100 rpm and almost full right rudder.
I shut the Cherokee down after taxiing to the ramp, and went to the maintenace shop, which pronounced the Cherokee in excellent shape. Next stop was Active Sky 16, to see what my settings were there. I went down to wind options/ Maximum wind shear, and saw that the default setting for this called for 50%, but it was set at
100% ( which I had not set it at). I reduced that to 40%. Then I decided to look at some other settings, and Max downdraft rate was at 2,000 fpm and default was
1,000 fpm. I then fired up the Cherokee, and took off again, on runway 29, and flew the pattern again, with no problem this time and made a good landing. From now on when I update AS16, which I did a week or two ago, I am going to recheck all the default settings.
That wind shear will certainly get your attention on short final.
