8/27/06

Of ground loops and slugs
C. G. Prince

Yesterday was my 10th cross-country flight, my 7th off-field landing, and my second fastest average speed. With Walt Johnson as crew chief, I flew from Osceola, WI to near Alma, WI (landing field lat/long: N 44° 24.708 W 91° 56.348) for some 72.2 statute miles distance. The flight took 2.25 hours, giving an average speed of 32.1 mph. In my last couple of cross-country flights, I have been trying to fly between 80 and 90 mph (with one notch of negative flaps on my SGS 1-35) between thermals to cover ground. This was my first usage of that strategy when flying downwind.

We got a late start on the day. The NOAA soaring forecast indicted that trigger temperature would be reached at 2pm. Lift started very near then, and due to variations in ground operation (e.g., other aircraft landing), I launched at 3pm. I had taken one tow earlier (around 1pm) but there had not been enough lift to keep me up. Cloud base was low at that time—around 3,000 MSL.

The conditions that day were hard to predict. It was foggy all the way down on my drive to OEO from Duluth, leaving the house at 6am. It was overcast through until about 10am, when things started to clear up. At around 2pm, both Walt and I had nearly given up on the day. We both thought that it was only a local flying day.

I changed my mind, however once I got up on that second tow. Tow pilot Lee Bradshaw called out a thermal on tow, and I released near it, and worked it. Shortly thereafter, I realized the lift was consistent, and with strength about 200 to 300 fpm. I was eager to set out on a cross-country as my last two cross-country attempts (Walt set up to crew on both) had resulted in local flying only due to poor lift. So, I started off on my course. Walt and I had agreed that I’d head SE. The wind was from the NNW. In no time at all I was near New Richmond, and Walt was underway in my truck pulling the glider trailer. Cloud bases were still pretty low. I think I got up once during the flight to 5,000 MSL, but usually I was flying between 3,000 and 4,000 MSL. Clearly, this is not a lot of wiggle room, but the lift was consistent and I had been having too many landings back at KOEO to stick around.

I have to admit that navigation was a bit of a challenge on this trip. I should have previously “overflown” my intended course using Google maps, but I had not. I found myself on the map over Ellsworth—the golf course north of the city was a fine landmark. From then on out, I felt a little less secure in my localization. I saw the Red Wing airfield, though for some reason I felt disoriented by the fact that the runway was running east-west. East just didn’t seem like east. But, I believed the directions I saw for the runway on the map. For some reason, at least in the navigation discussions I’ve had, people don’t seem to emphasize the fact that when thermalling, it’s very easy to become disoriented. You are circling and focusing on working the lift (and maybe refolding your map!). Of course, one becomes disoriented with regard to compass directions. It even takes the compass a little while to become settled when you level out! One additional reason that I think I became disoriented at times during this flight was that the land east of the Mississippi that I was flying over had lots of rolling hills that looked similar. I really wanted to be flying more towards the east (e.g., over Spring Valley and Durand), but found it tough to fly between those places from landmarks (or lack thereof) on my map. So, I gravitated to the nearest simple landmark—the Mississippi. In hindsight, I should have written compass bearings on my map or my knee-board to get from landmark to landmark.

When I got south of the Chippewa river, I started to struggle. I got down to about 2,500 MSL but managed to climb back up to around 4,000 MSL. I had a landing field candidate in sight at that time, but subsequently lost sight of it in my climb. Shortly thereafter, I found myself low again, and looking for fields. I couldn’t find the field I’d seen before, and there just didn’t seem to be any really good fields. Lots of rolling hills and crops. I selected one that ran north-south, to land up-wind. It did have a power line running along a road to its west side, but I felt confident that I could put the glider down in the middle of the field and avoid this obstacle. The sight of the power line should have brought one more thought to my mind—to set up my pattern to not over fly the power line. It turned out that the elevation of my landing field was about 400 feet above that of OEO. Because I chose, out of habit, to fly a left-hand pattern, this put me overflying the power lines on my base leg. If recall servers, my altimeter read about 1700 to 1600 as I overflew the power lines. After landing, my altimeter read about 1200 to 1300 (www.topozone.com indicates the field elevation at 1250 MSL). A right-hand pattern would have avoided overflying the power lines and hence avoided this particular stress element.

I touched down somewhat before mid-field. The crop was about 1-2 feet high, and I think the touch down was OK. The rollout also seemed fine until I was getting slow. At that point, the left wing tipped down, and I ground looped. It seemed odd as I was moving relatively slowly, and yet the glider did a 180 degree turn and I ended up looking back at the way I came in. I had been fortunate too in that I’d touched down on the up-hill of the gentle rolling hill of the alfalfa field. This slowed me down some (my roll-out was about 37 of my paces long).

After getting out of the glider, I found that my cell phone had no reception. A farmhouse was near (one of my personal field selection criteria is to try to land near a house of some kind), and so I walked to it. The first person I met was out for a stroll along the road, knew that the thing in the field was a glider (unusual!), but didn’t have a phone. So, I walked the rest of the way to the farmhouse. It turns out the farmer had seen me land, and alerted his son, Dan, to my presence. I showed Dan the glider, we started derigging, and he made about 6 phone calls for me (his cell phone had reception) in my attempt to get in touch with Walter. Finally, I got through to Walt, and he was only about 10 minutes drive away. Dan then drove me a couple of miles down the road to meet up with Walt, to make sure he found his way. With Walt at the field, I gave Dan my traditional offering of a glider ride certificate piloted by myself (he had to leave on a date with his girlfriend), and Walt and I started derigging the glider. We had plenty of sunlight left. Next time I rig, I expect to find some slugs remaining on my glider from where I’d temporarily put parts in the alfalfa field!

Landing field:

http://www.terraserver-usa.com/image.aspx?T=1&S=10&Z=15&X=2922&Y=24588&W=3