Reviewing the Ridge Map, I noticed some appalling landouts associated with ridge flying. Falling off of a ridge is about the most dangerous kind of landout situation a soaring pilot can encounter. When you fall off, you typically have very little time and few options to choose from. Usually you must do an abbreviated pattern into your field. Fields near mountains tend to be shorter and more rolling, also increasing risk. These factors require serious consideration in order to make a safe landout.
The disturbing feature of many ridge landouts is the tendency of pilots to make *very low* patterns/approaches into fields. A lot of this is due to their attempts to thermal in weak lift after having fallen off the ridge. I suspect that pilots get more comfortable thermalling low when they spend a long time very close to the trees. The same pilots who would quit well above 500ft are attempting to dig out from 300ft AGL! This is followed by a full pattern initiated at 200ft AGL!
However, looking at these trends, I suspect that pilots lack some guidance as to how to properly conduct a ridge landout. As such, here are some thoughts and guidelines to take a very dangerous situation and make it considerably more manageable.
In crucial areas like gap crossings (transitions) or in areas with sparse landing options, it is critical that you know beforehand what your options are. Where fields are sparse, the few fields that are available tend to be marginal. Moreover, you might be forced to make a very low approach into a marginal field that has only one way in. Knowing what you are dealing with and having a plan beforehand can be the difference between success and totalling your glider. When it comes to gap crossings, you might have to make a straight-in into your option. If you know your options and are prepared to do so, your odds of success are a lot better.
Falling off a ridge rarely happens in a heartbeat!
Your situation will slowly deteriorate and you can pick up on this well before you have to commit to a landout. If the ridge is softening up, you will be getting lower and slower. There will be an eery smoothness to the ridge, punctuated by weak little bubbles that hardly improve your energy situation. When you feel this happening, this is your cue to take the next thermal if you find one. At the same time, you should start paying a lot of attention to the fields in the valley below.
When the ridge is soft, you should be flying “field to field”. If you’re hanging on the ridge, then keep finding each successive field that you could land in. Should the ridge go from soft to not working, you will be ready to land. Don’t go into an unlandable or marginal area ahead if the ridge is soft!
Remember that many ridge fields can be marginal, so you have to be vigilant in your field selection. Pay a lot of attention to the field’s slope. The best case scenario is that you find a field that has a favorable slope and is perpendicular to the ridge. This way you are on “base” leg while on the ridge. If you choose to commit to the field, then you will have from 500-1000ft AGL to work with, quite reasonable! You will also be landing into the wind, good news! Fields that are parallel to the ridge are fine too, but make sure that you picked up the right side to make your approach.
Falling Off the Back
Sometimes your only good options are on the downwind side of the ridge. These are very tricky situations for several reasons. The first is that you usually have to leave the ridge at a higher altitude than you would if you had a field on the front side. Some ridges have a broad, flat peak and you have to maintain enough altitude to clear over the top of it. This goes back to the business of committing while you still have time and options. Plus or minus 10 seconds can make the difference between clearing the mountain comfortably, to being marginal, to not having enough altitude to make it over. Remember that settling down on the mountain does not happen instantaneously. If the ridge is not supporting you 500ft above, 300ft above, 200ft above, it’s probably not going to do you much good 100ft above the trees. If you’re getting scared, act on it sooner than later.
Secondly, the wind flows on the backside of ridges can be unpredictable and violent. You are heading into the lee sink of the mountain and the wind can curl and do all sorts of wild things. Expect turbulence and sink. Keep your speed up and try to find a large field.
In thermal soaring, we are trained to transition into “landing mode” at an appropriate altitude. When ridge soaring, we delay this point to an altitude that is considerably lower than under normal conditions. However, the moment you fall off the ridge, this should be your cue to transition into landing mode. Especially if the ridge is weak or you fell off halfway below ridge top, you are likely to be at or below 500ft AGL of the valley floor. You need the altitude to make a safe approach and landing into what is likely to be a trickier than normal field.
Also, the earlier you accept the ridge is not working, the better. If you can’t hang on a ridge 50ft below ridge top, it is probably not going to get better 100-200ft below either. There are exceptions, such as if the ridge is turning toward a more favorable wind angle. But all things being equal, the earlier you accept that the ridge isn’t working, the better. Ridges tend to be sharp at the top and flatter sloped at the bottom. If you leave early, you will maintain a reasonable height AGL, especially if you have to go a ways toward a field in the valley. If you delay several hundred feet, you will be hugging the terrain on your way toward the fields; bad news.
Also, if the ridge is reasonably high, the earlier you leave, the better chance you will have to find a thermal in the valley. Every 100ft makes a big difference in connecting with that thermal. Don’t delay leaving a ridge that isn’t working.
Now that you’ve committed to landing and picked out your field, you need to deal with the fact that you will probably have to make a low approach into the field. If you don’t have enough height to make a normal pattern, don’t. It is much better to be higher and do an abbreviated approach rather than a low, full pattern with all the associated risks of a stall/spin.
If I have to use an abbreviated pattern, I like to use the “hangglider technique”. I position myself offset from the field and S-turn until I am in a comfortable altitude to make an approach into the field.
In sum, maintain situational awareness of your options, accept defeat early, commit early, and make a safe approach in a field.