S-turns on final

Ok, I'll bite.

I prefer S turns to slips, but that's more about the glider I am flying today. And, when I say S turns, I usually mean two easy turns (back and forth) in order to make the final approach as long as possible. This is usually in a land out situation, dealing with trees on the approach end of the field and only if very, very high (above a full spoiler descent). Basically S turns are the result of a fairly large miscalculation. That would be rare however as it's usually far easier (and safer) to do a circle at 75mph, if truly too high for a safe full spoiler approach. So doing S turns is very rare with the effectiveness of modern spoilers and the performance of even modest performance sailplanes.

All glider turns (at 'almost' all times) must be perfectly coordinated (or any aircraft for that matter). This must be natural for the pilot, effortless in fact. That's the key focus for the pilot during the execution of all turns, correct? Especially so when near that hard thing known as the ground. So, if you are proficient with the basic skill of coordinated flight and follow that key rule, you're fine with a couple S turns. If you don't have that natural skill developed, if your sloppy, your risk is immediately.. That's a far broader problem than S turns.

So S-turns are very safe if you are properly trained and therefore fly the glider properly at all times without stress or difficulty. The only exceptions would be 1) slip landings (which is not very effective (to nil) in a high performance sailplane, in my humble opinion) and therefore I never use slips when flying my personal glider. If attempted (I have tried them a few times), they are very scary as the slip angle must be quite extreme in order to create any meaningful drag. -or- 2) utilizing a slight top rudder configuration whilst thermalling.

Slips work great in a 2-33 or a 126. But even a Grob 103 is fairly poor at slipping. An ASG29 or Lak17a (my experience) gets virtually zero benefit from slipping (my opinion) even in an extreme slip. And with full spoilers, flying relatively slow (65 mph) and at extreme slip angle is not what I want to be doing in any modern sailplane at 200-300 ft (again, my opinion).

Bottom line, turn coordination must be job one for all pilots at all times, from student pilots to advanced pilots. It must be natural and without exception, especially when under stress. When that skill breaks down, the risk increases dramatically at all stages of flight.

So as with all things, and with the question of slips or S-turns (IMO) it depends on the many circumstances involved.

Ok, I'll bite.

I prefer S turns to slips, but that's more about the glider I am flying today. When I say S turns, I mean two easy turns (back and forth) to make the final approach as long as possible. Not 5-10 sharp back and forth turns, for example. In my experience, an S turn is usually employed during a land out, and often when dealing with tall trees on the approach end of the field or a short field. S turns are an easy way to fine-tune the approach, without extreme glide angles, extreme changes in spoiler power or (low) airspeeds (hard slip, full spoiler). But S turns are very rare (for me) as it would be far easier (and safer) to do a simple circle at a consistent and higher airspeed, rather than a couple big, sharp S turns. So doing S turns (or slips) is very rare with the effectiveness of modern spoilers and the glide performance of even modest performance sailplanes.

All glider turns (at 'almost' all times) must be perfectly coordinated (any aircraft for that matter). Coordinated turns should be natural for the pilot, entirely effortless in fact. That's the key focus for the pilot during the execution of all turns, correct? Especially so when near that hard thing, otherwise known as the ground. So, if you are proficient with the basic skill of coordinated flight, you're fine with a mild couple S-turns on final. If you don't have the natural ability of proper turn coordination developed, risks are higher (especially when under pressure). That's a far broader problem than slips or S-turns.

So S-turns are very safe the pilot is properly trained and therefore flies the glider properly, at all times, without stress or difficulty. The only exceptions would be 1) slip landings - not very efficient (to nil) in a high-performance sailplane and therefore I never use slips when flying my personal glider. If attempted (I have tried slips a few times), they are very scary as the slip angle must be quite extreme to create any perceivable drag. -or- 2) utilizing a slight top rudder configuration while thermalling.

Slips work great in a 2-33 or a 126. But even a Grob 103 is fairly poor at slipping. An ASG29 or Lak17a (my experience) gets virtually zero benefits from slipping (my opinion) even in an extreme slip. And with full spoilers, flying relatively slow (60 mph) and at extreme slip angle is not what I want to be doing in any modern sailplane at 200-300 ft (again, my opinion). But in lower performance trainers, slips are perfectly practical and even fun.

Bottom line, turn coordination must be job one for all pilots at all times, from student pilots to advanced pilots. It must be natural and without exception, especially when under stress. When that skill breaks down, the risk increases dramatically at all stages of flight.

So as with all things, and with the question of slips or S-turns (IMO), it depends on the many circumstances involved.

On Tuesday, February 14, 2017 at 7:47:49 AM UTC-8, kirk.stant wrote:
On Monday, February 13, 2017 at 5:54:51 PM UTC-6, Matt Herron Jr. wrote:

S turns on final seems like a great way to get uncoordinated and kill yourself. Count me out.

Matt

Really? How are S-turns any different from normal turns in a pattern, especially if you have to setup for a crosswind on final?

Perhaps you are not comfortable with turns at low altitude? That in itself is pretty dangerous, more so than the actual turns.

Watch out on the ridge!

Kirk
66

What is the most dangerous turn in pattern? Base to final. S turns on final will be even lower. Shallow turns really aren't going to loose much altitude for you. If you are so high that spoilers are not going to do the trick, you will need substantial deviations in your S turns to get back on glide slope. In addition to a greater risk of stall/spin, this also makes you unpredictable to others in the pattern. Button hooks are also considered dangerous on the turn to final, and S turns really aren't much different in my mind. Add a 15 knot x-wind, wind gradient, and turbulence and the situation is not good for a bunch of turns at 200 ft

I am sure S turns would be appropriate in some instances, especially for traffic spacing, but I would personally pick a slip first to correct a glide slope problem if at all possible.

On Tuesday, February 14, 2017 at 8:47:11 AM UTC-8, Sean Fidler wrote:
Ok, I'll bite.

I prefer S turns to slips, but that's more about the glider I am flying today. When I say S turns, I mean two easy turns (back and forth) to make the final approach as long as possible. Not 5-10 sharp back and forth turns, for example. In my experience, an S turn is usually employed during a land out, and often when dealing with tall trees on the approach end of the field or a short field. S turns are an easy way to fine-tune the approach, without extreme glide angles, extreme changes in spoiler power or (low) airspeeds (hard slip, full spoiler). But S turns are very rare (for me) as it would be far easier (and safer) to do a simple circle at a consistent and higher airspeed, rather than a couple big, sharp S turns. So doing S turns (or slips) is very rare with the effectiveness of modern spoilers and the glide performance of even modest performance sailplanes.


My 29 slips great, every effective, huge. From early training I have been taught that a 360 turn low while adjusting glide path for an out landing can get you into real trouble. You are turning away from intended landing site and losing sight of the touchdown area. I do regularly practice slips on downwind, base and final making all the turns while in a slip (but then one day a week I get to fly rides at the local glider port so I have many opportunities). Have I flown a 360 low while landing out, you bet I have, but in my humble opinion this should be discouraged. With the landing flaps (sorry std class), slips, spoilers and the ability to plan ahead we have lots of options rather than S-turns, but they should be in a quiver of skills as you never know what circumstances you might find yourself in and it helps to have a full bag of skills.

On Tuesday, February 14, 2017 at 10:48:26 AM UTC-8, Jonathan St. Cloud wrote:
On Tuesday, February 14, 2017 at 8:47:11 AM UTC-8, Sean Fidler wrote:
Ok, I'll bite.

I prefer S turns to slips, but that's more about the glider I am flying today. When I say S turns, I mean two easy turns (back and forth) to make the final approach as long as possible. Not 5-10 sharp back and forth turns, for example. In my experience, an S turn is usually employed during a land out, and often when dealing with tall trees on the approach end of the field or a short field. S turns are an easy way to fine-tune the approach, without extreme glide angles, extreme changes in spoiler power or (low) airspeeds (hard slip, full spoiler). But S turns are very rare (for me) as it would be far easier (and safer) to do a simple circle at a consistent and higher airspeed, rather than a couple big, sharp S turns. So doing S turns (or slips) is very rare with the effectiveness of modern spoilers and the glide performance of even modest performance sailplanes.


My 29 slips great, every effective, huge. From early training I have been taught that a 360 turn low while adjusting glide path for an out landing can get you into real trouble. You are turning away from intended landing site and losing sight of the touchdown area. I do regularly practice slips on downwind, base and final making all the turns while in a slip (but then one day a week I get to fly rides at the local glider port so I have many opportunities). Have I flown a 360 low while landing out, you bet I have, but in my humble opinion this should be discouraged. With the landing flaps (sorry std class), slips, spoilers and the ability to plan ahead we have lots of options rather than S-turns, but they should be in a quiver of skills as you never know what circumstances you might find yourself in and it helps to have a full bag of skills.

On a scale of "ease to get rid of altitude on final", The ASG29 would be very near the easy end. Almost as much fun as ASW17 drag chute landings with full spoilers.
Jim

My 29 slips great, every effective. From early training I have been taught that a 360 turn low while adjusting glide path for an out landing can get you into real trouble. You are turning away from intended landing site and losing sight of the touchdown area. I do regularly practice slips on downwind, base and final making all the turns while in a slip. Have I flown a 360 low while landing out, you bet I have, but in my humble opinion this should be discouraged. With the landing flaps (sorry std class), slips, spoilers and the ability to plan ahead we have lots of options rather than S-turns, but they should be in a quiver of skills as you never know what circumstances you might find yourself in and it helps to have a full bag of skills.

I tend to turn high final. Slipping my ASW 24 with full dive brakes steepens the approach significantly with little drama. If it's a short final, a slipping turn lets me start sooner. I slipped my 201 Libelle with smaller dive brakes all the time. Hardly ever my LS-3 because the brakes were so effective. A slip also allows moving laterally using more or less aileron to slide into position when the runway approach is unobstructed but the approach to the parallel taxiway is not quite so clear, as is the case at several East Coast airports I've flown out of.

I use S turns when I want to do the opposite: i.e., I've turned high final and do NOT want to lose a lot of altitude quickly. For example, when allowing another, lower glider to turn in ahead of me and land long (not uncommon at a site like New Castle when multiple gliders are finishing at different altitudes all needing the same runway). I also use S turns occasionally to check out a field when I'm landing out. And to lose altitude in front of a hill blocking a normal approach. S turns--taught as part of the standard course when I learned how to fly in the 60s--means never losing sight of the landing spot and are much preferred/safer compared with a 360 on final. If a 90 degree turn base to final is safe, I'm not sure why one or more 180 degree S turns at a higher altitude aren't just as safe so long as they're coordinated and the speed is controlled. Actually it's usually slightly more than 180 degrees when the objective is to descend slowly while not getting closer to the landing spot. And I usually have short intervals of straight flight between the turns so it's not one continuous series of rolling back and forth.

Just my opinion.

Chip Bearden

Gotta agree with Sean on this one. Sometimes you don't WANT to expedite the landing. Slips and spoilers decrease the time you are in the air. Sometimes delaying the touchdown while maintaining controlled coordinated flight is necessary if the runway is not clear, but might be safe few seconds later.

Remember that your "S-turns" should be MORE than 180 degrees to keep you from moving closer to the end of the runway. Really, your turns should resemble an elongated figure 8 with the crossing over a point aligned with the runway centerline. Round out of your final turn on to the final approach when the runway is clear, or your personal safety margin is reached. Remember that you are LOW, so SLOW turns are putting you in that nasty corner we are reminded of in every other article we read about in "Soaring" magazine. Keep your energy up!

If the runway is not clear yet, use full spoilers to minimize the runway length needed, touch down with as much margin as possible and get on the brakes. Steer off the runway at minimum speed to avoid the obstruction (aircraft, emergency vehicle, etc.)

Of course, if you have sufficient runway past the obstruction, overflying and landing long is a completely acceptable option. Better to be chastised and eventually forgiven than being carted away in an ambulance.

S turns on final:

http://www.onlinecontest.org/olc-2.0...l?dsId=5523393

Boggs

On Monday, February 13, 2017 at 2:45:27 PM UTC-5, Jonathan St. Cloud wrote:
Came across a blast from the past on youtube. There was a video of teaching s-turns for glide path control. Looked to be from the 40's. Not sure why they would teach this when a slip would be safer and more effective.

If the pilot has the skills and judgement to use S turns on final without reducing safety margins, he or she most likely would have the skills and judgement to not need them.
UH