Given that one needs at least 30 degrees of bank to accomplish this, is there not a danger of a spin-in?
Why does one need 30 degrees to do S-turns on final approach? Is this a British regulatory or standards requirement? There's no such practical need. Practically speaking, one can do a steep turn on final without stalling or harm, or one can do very mild banking to do S-turns.
There's no reason to expect a spin simply from doing S-turns. The airplane won't spin unless you allow it to spin.
Actually I recall from reading Langewiesches Stick and Rudder that it is that simple, and aircraft that were impossible to stall (and thus, spin) have been done in the past. Precisely by limiting elevator travel.
Wolfgang's book is somewhat outdated, and while making for good reading, is not technically correct, and is not accurate. As a general picture, perhaps, but don't take it to heart.
Efforts have been made to create unspinnable aircraft. The Ercoupe was one such effort, albeit unsuccessful. Limiting elevator travel will NOT prevent a spin.
At higher speed, wing DOES stall at the same stick position (as close as I can measure it), but at significantly more G loading (provided the wings don't drop off..)
A stall has no bearing on stick position. Stall is a function of angle of attack, not stick position, not pitch angle, not power setting, not weight, not center of gravity...but of angle of attack for a given aircraft configuration.
I can demonstrate for you quite easily a stall in a variety of stick positions in the same aircraft; forward, aft, neutral, along with a variety of ways to stall the aircraft. I can also do the same thing in order to enter a spin. Divorce in your mind the concept of stick position and angle of attack; they are not related, and marrying the two concepts can simply confuse you...or get you killed. Relating stick position to a stall is a fallacy, and a dangerous misunderstanding of basic aerodynamics, and basic airmanship.
Furthermore, pilots have been killed stalling and or spinning an airplane with the control lock in. No aft travel at all, and pitch taking place as a consequence of power setting.
Given the extensive variety of aircraft available, one shouldn't attempt to make such broad, sweeping statements as the notion that an aircraft can't stall or spin if stick motion is limited. I've been able to fix the stick in position and move the airplane about simply by standing and leaning this way or that...I could just as easily stall the airplane, and subsequently spin it without any stick motion at all, if I desired.
In other words: when you pull back at the stick, the aircraft will stall at the same stick position, regardless of speed, actual weight/balance, altitude and a number of other factors. As long as you keep the stick/yoke forward of this position, you will not stall or spin.
This is 100% untrue. The aircraft will stall at the same angle of attack for a given configuration, but not the same stick position. Given more experience in aircraft, or a variety of aircraft, you'll realize this. An aircraft can be stalled with the stick forward or aft, and CG will have a significant bearing on the position of the stick, as will power setting, etc. The aircraft can be stalled slow or fast, pointing skyward or at the ground, light or heavy...and the stick position will vary throughout those regimes.
Now...as far as sideslips and forward slips go...
When I was younger and inexperienced, I was a big user, and a big proponent of the slip. Much easier than reconfiguring the aircraft, it's really just "free" drag...and unlike lowering flaps or doing something else to alter the aircraft configuration, the slip can be instantly disposed, with an instant performance recovery.
This comes at a price, however, and one that's seldom advertised. I've seen it on big aircraft and small, and I've personally handled the broken parts and seen the trends. One seldom hears it mentioned, but a slip puts an enormous air load, even at low airspeeds, on the vertical stabilizer. In many aircraft, including most light airplanes, one might be shocked to find out just how little is holding that vertical stab in place...usually two brackets or bolts.
I maintained a fleet of 30 single engine Cessna's years ago, that were used for mountain flying, tours, sightseeing, and a lot of canyon work. Slips were used a lot to get into some of the strips we used, and regularly used for landings, and other types of flying that we did. I found a trend among many of the airplanes; cracked vertical stab attach brackets...meaning complete failure of the part. As a result of the findings, the parts were changed from an aluminum alloy, to steel. Never the less, we found more cracks.
I've found them on large four engine airplanes (which we also aggressively slipped into canyons in exactly the same way we do it in light airplanes) during inspections. We've learned in recent years, with fortunately more publicity, that airplanes can be broken at speeds considerably less than Va...something that many didn't believe would happen, just a few years ago. Slips are hard on the airframe.
Now, I've done a lot of flying in airplanes without flaps, and slips are often used in such airplanes. I don't do slips as a rule, any more, regardless of what I'm flying, because I know the cost and the stress on the airframe.