Cultivated farm fields
The optimum farmland out site would be a recently harvested, +500-meter (1640 feet) field with recently cut crop rows aligned with the wind, having an unobstructed approach (preferably over water and not across a road), near a farmhouse, and having an obviously visible gate. [and while having this fantasy – which of course never really happens – I could add a restaurant & bar across the street!]
So, let’s discuss each of these factors separately:
This, of course, is fundamental on a land out. We are trying to minimize the energy of the glider touching down on an unknown and variable surface that was never designed or groomed for an aircraft landing. This is best done by selecting a field-oriented within 30 degrees of the prevailing surface wind direction and then touching down as slowly as possible.
Freshly plowed or newly planted fields will have very loose surface soil causing the glider’s main wheel to dig in quickly and resulting in an abrupt stop, a dirt-impacted wheel well, and probable gear door damage. This will also cause difficulty in moving the glider or getting the trailer to the glider later. If you must land in such a loose/soft field, try to touch down as slowly as possible after aligning the fuselage with any tractor tire prints that you see on the final approach (another reason to select a field with crop rows into the wind). The ground will be hard-packed under the tractor tire prints. A better choice would be a field with low crops (again try to land slow and on tire tracks). You are not likely to do much damage to a new and low crop. The best choice is a recently cut field where the sun has baked the field hard and the residual stubble holds the surface together. The glider rolls well on such a field and the landing is normal.
Size of the field
The necessary size for a successful land-out-field is a function of the particular pilot’s experience and skill set, plus any obstacles that must be cleared in the approach to the field. No single rule works for everyone and every glider, but the suggested 500 meter/1650 feet should work for most new pilots in non-flapped gliders. A very experienced pilot in a flapped machine could use one-half of that length successfully. Obviously, obstacles on approach eliminate some usable distance so more is needed. Newer, less experienced pilots should select larger fields with unobstructed approaches, even with a sacrifice as to the surface type of the field. For your first few land outs, “size matters” and bigger is better. Don’t put yourself into a position where you have to execute a perfect low-energy approach and landing to be successful.
Landing a slippery modern glider on a downhill slope is highly problematic and runs contrary to our goal of minimizing the energy at touchdown. Accordingly, careful consideration of the terrain slope is part of the good land-out-field selection. We are helped by remembering that water flows downhill and that fields always slope towards nearby bodies of water. Thus, the ideal field will have an approach over a pond, a stream, or a swamp and into the field. Avoid field selection where you are headed toward water immediately beyond the field. That situation is likely to lead to a downhill landing.
In my opinion (formed after 50 years in the sport), wire strikes are the greatest hazard in off-field landings. This is because from the air and looking at the ground, it is almost impossible to see wires – especially if they are running alongside a dark-colored road. Telephone poles are just as hard to see (although sometimes we get lucky and can see their shadows). For this reason, we should avoid selecting a field that requires our crossing any road or driveway on the final approach. If we must cross a road then some safety height near the road must be maintained. We have to assume that there will be wires along the road that we can’t see. Our search for and suspicion of wires should begin as part of the field selection process. Is there a farmhouse or building nearby? How does electricity get to that structure? Can we see pole shadows anywhere? Is there something showing in the field that could be the base of a pole with wires? And the danger isn’t over when you see the poles or wire towers: Frequently electric poles and towers have visible bows of thicker wires in their lower sections, but they also have very thin wires (overhead ground wires for lightning strikes) up higher. For this reason, if we must land over wires, we always fly directly over a pole or tower and never between them. This is because there can’t be a wire higher than the pole top.
Less important considerations
There are several factors that can be grouped under the heading of “good form” but are not essential to safety and can be relegated to being of secondary concern. Don’t sacrifice or compromise a safe landing for any of these. First, it’s nice to select a field that is a reasonable walk to a farmhouse (but don’t be surprised if the farmer is not at home) or to a paved road. Even a few miles of driving on a washboard dirt road is not good for the glider or trailer. It’s also nice to locate (from the air) the gate into the field and to stop the glider near it. This is especially true if it’s a soft field and you can’t roll the glider to the gate or drive the trailer to the glider. Of course, don’t be surprised if the gate is locked. If there are other gliders low and scratching in your area, it’s nice to be considerate and leave them room to land too. I once had a contest land out at a private strip where another guy landed first, stopped dead in the middle of the tiny runway, and started chatting with the owner, while I got to practice all of my short-field landing techniques… Source: ‚Wingsandwheels, Roy Bourgeois‚.