Sometimes, they just look bad
A tight, even curvy launch area can look daunting but, for someone able to steer their launch run, it’s no more dangerous than a wide-open site. The key is being able to steer your launch run and know that the area is wide enough. Furthermore, the climbout path must allow for engine-out options. Of course a constricted site will be less forgiving of error and strong winds (over just a few mph).
Time of risk is the period where an engine failure would result in landing somewhere unpleasant. Ideally that time will be zero although, occasionally, we accept some amount of known risk. Work out flight paths or procedures in advance to minimize exposure. The best example is water. If you’ll be launching somewhere that could result in wetness after engine pukage, wear an Agama and/or life vest.
Avoid sites that require climbing over tall obstructions—not only do they increase your time of risk, but they require performance that you may misjudge. That’s a very common error that put pilots in trees and power lines. “I think I can make that” has preceded numerous trips to the hospital. Measure it so that you can know. Of course you must have also measured your no-wind performance at home and know what that is.
Launching from a confined area is about picking a path and sticking with it. As long as you have about 1.5 times your wingspan along a launch path, and are able to steer the launch run within about 5 feet, you can launch about anywhere.
Once your measurements are made so that the course is known, then your job on launch is simply following that path. It’s best to have a wide area at initial inflation so you can accept a crooked inflation and have room to get under the wing and steer it back. Once the wing is up, concentrate on the path, not the obstructions. If you get more than a few feet off the chosen course, abort.
Below is a short video on one of my back-yard launches. These really aren’t that confined but, by treating the centerline as the target path and putting out fixed-distance cones, I can accurately gauge how much room I’ll need in a true confined area.
Landing is another story, with a potentially very dangerous plot. Mostly because it involves steeping the glide by pulling lots of brakes. Truly tight areas will not allow S-turning and heavy brake pressure requires intimate knowledge of your wing and having a feel for when it’s about to stall or spin.
Even for an experienced pilot, landing in a confined area carries some amount of increased risk although it can be greatly minimized.
Sorry about the audio. This was cut together on an overnight and narrated through the built-in sound recording.