- Time of year
- Where you are flying
- Undulations
- Ridge and furrow
- Fences
- May be marked by a defined change in surface colour.
Look for fields in the following order:
- Stubble.
- Grass, but beware of strip grazing indicating electric fences; any shading in grass surface almost certainly indicates the presence of fencing.
- Short crop. The surface should appear more brown than green.
- Other cropped fields may present a hazard on landing. Remember, half-ripe crops may look like stubble. Consider the season!
The most suitable field surface varies with the season. In the spring, the short crops in harrowed fields will offer the widest choice. After harvest time, stubble fields are by far the best, but there is a time just before cereal crops are ripe when they can look very like stubble which has been undersown with grass. Even at seven or eight hundred feet it can be difficult to tell the two apart, and the real protection comes from an awareness of crop state throughout the season: you do not have to be flying to notice this.
Grass fields are notoriously misleading if they are divided for strip-grazing; detection of the fences relies on the field having been used recently. If it has not, it will be difficult or impossible to tell. A pasture that has not been used as anything else for many years may well be rough and have tussocks.
One particular variety of field is known as ‘ridge and furrow', there are certain parts of the country where this is, or was, the practice. The method of ploughing creates the undulations which may be as much as eighteen inches from peak to trough. To land across the ridges would almost certainly break the glider and landings must be made as in a ploughed field – along the furrows.
Fields with animals in them present problems which depend on the type of animal. The curiosity of cows is notorious, and you may well have to defend the glider against them until help arrives.