Jay showing us how it's done
Don
Me
Aerotow Practice in Casa Grande
Aerotow Practice in Casa Grande
Don't know if this qualifies as an "Amazing Flight" but Jay, Don and I had a lot of fun brushing up on our aerotow skills this weekend in Casa Grande, AZ. Everyone had good safe flights/landings and no downtube casualties. Here's some photos:
Jay showing us how it's done
Don
Me
Jay showing us how it's done
Don
Me
Wish I were there
Eric,
I'm glad that worked out. So everyone is ready for Dustin Martin'c X-C clinic now? You guys will then become be the club's resident experts and can teach the rest of us noobs.
Jonathan
I'm glad that worked out. So everyone is ready for Dustin Martin'c X-C clinic now? You guys will then become be the club's resident experts and can teach the rest of us noobs.
Jonathan
AT Help
I'm interested in hearing from any/all experts as to why Jay's launch looks radically different - and probably better - than mine? 
Notice the significant difference in Jay's agl and glider angle than mine.
Comments?
Suggestions?
I'm listening.
Notice the significant difference in Jay's agl and glider angle than mine.
Comments?
Suggestions?
I'm listening.
Re: AT Help
I'm definitely no expert, but to me it looks like Jay is pulling in more so that his climb angle is lower. His being a topless glider may also have something to do with it.Don wrote:I'm interested in hearing from any/all experts as to why Jay's launch looks radically different - and probably better - than mine?
Notice the significant difference in Jay's agl and glider angle than mine.
Comments?
Suggestions?
I'm listening.
Just a thought.
Allen
You mean your asking for public abuse 
Here's what I can see. Jay is flying out of the cart. Good body position, and pulling in as he should. He likely has a bit of VG on as well (I know I do when towing). Looks good doesn't he?
Both of the other shots you can see your "popping" off the cart, and not flying out of it. Both work, and both have their respective issues.
Popping off the cart will often lead to a higher "likelihood" that you'll experience a weak link failure.
Flying out of the cart puts you lower right as you leave the cart and can be dangerous if the glider descends suddenly. But if you pickup the wheels slightly as your leave the cart, I have found this to not be an issue (but it can happen).
When we were in AZ last year we saw a lot of weak link failures as a result of pilots popping off the cart to get above the dust cloud. This may have been the case for you guys too (although subconsciously).
If your going for style points then Jay looks way cool
Here's what I can see. Jay is flying out of the cart. Good body position, and pulling in as he should. He likely has a bit of VG on as well (I know I do when towing). Looks good doesn't he?
Both of the other shots you can see your "popping" off the cart, and not flying out of it. Both work, and both have their respective issues.
Popping off the cart will often lead to a higher "likelihood" that you'll experience a weak link failure.
Flying out of the cart puts you lower right as you leave the cart and can be dangerous if the glider descends suddenly. But if you pickup the wheels slightly as your leave the cart, I have found this to not be an issue (but it can happen).
When we were in AZ last year we saw a lot of weak link failures as a result of pilots popping off the cart to get above the dust cloud. This may have been the case for you guys too (although subconsciously).
If your going for style points then Jay looks way cool
Jay always looks way cool.
Thanks for the analysis, Chip. I like the idea of thinking of it as "flying out of the cart". I was just feeling for when the front wheels on the dolly started lifting and then letting go. Although I didn't consciously feel myself pop-up, i'm sure the sudden letting go of the cart causes a change in angle of attack resulting in the higher nose position Don and I have. Not only does this increase the likelihood of the weak link breaking, but would it not also increase the risk of stalling if it did break?
I think having more speed with a lower angle of attack slightly lower to the ground would be better than less speed higher angle of attack slightly higher to the ground. Just like landing at Kagel, coming in with speed/energy into a rollout/ground effect is better than mushing in at a higher height and leaving yourself susceptible to a stall or a turn.
BTW, I found it much easier to tow with 3/4 VG on. I was increasing it throughout the day and that seemed to be the sweetspot on the Sport 2. I think Don was using 1/2 on his Litesport.
Thanks for the analysis, Chip. I like the idea of thinking of it as "flying out of the cart". I was just feeling for when the front wheels on the dolly started lifting and then letting go. Although I didn't consciously feel myself pop-up, i'm sure the sudden letting go of the cart causes a change in angle of attack resulting in the higher nose position Don and I have. Not only does this increase the likelihood of the weak link breaking, but would it not also increase the risk of stalling if it did break?
I think having more speed with a lower angle of attack slightly lower to the ground would be better than less speed higher angle of attack slightly higher to the ground. Just like landing at Kagel, coming in with speed/energy into a rollout/ground effect is better than mushing in at a higher height and leaving yourself susceptible to a stall or a turn.
BTW, I found it much easier to tow with 3/4 VG on. I was increasing it throughout the day and that seemed to be the sweetspot on the Sport 2. I think Don was using 1/2 on his Litesport.
Chip's analysis is spot on. (As much as you can tell from stills, of course.)
I personally prefer to be faster. Higher doesn't help much if you are slow unless you are a LOT higher than we are talking about. Speed can help a lot.
Eric's comment that lower/faster is better than higher/slower is also right. Unless you are talking too low... There's obviously (as Chip notes) an altitude you don't want to be below.
Glad you guys had fun and came home safe.
I personally prefer to be faster. Higher doesn't help much if you are slow unless you are a LOT higher than we are talking about. Speed can help a lot.
Eric's comment that lower/faster is better than higher/slower is also right. Unless you are talking too low... There's obviously (as Chip notes) an altitude you don't want to be below.
Glad you guys had fun and came home safe.
Fly High; Fly Far; Fly Safe -- George
launch
Dust was an issue - especially after the first couple of tows.
The concern I have with Jay's pattern (and compounded by the lack of visibility) is the small margin of error if for any reason the glider descends - slight pulling in on the base bar, turbulence, etc. The ground is really uncomfortably close.
I'm not sure the angle of attack concern is valid - I thought that as long as you are being pulled a stalled is not possible ?
To the best of my recollection I don't think I ever let the front wheels of the cart ever leave the ground - but it was REAL close to happening.
Chip & George - thanks for the comments.
I'm still interested in hearing from anyone else with experience.
The concern I have with Jay's pattern (and compounded by the lack of visibility) is the small margin of error if for any reason the glider descends - slight pulling in on the base bar, turbulence, etc. The ground is really uncomfortably close.
I'm not sure the angle of attack concern is valid - I thought that as long as you are being pulled a stalled is not possible ?
To the best of my recollection I don't think I ever let the front wheels of the cart ever leave the ground - but it was REAL close to happening.
Chip & George - thanks for the comments.
I'm still interested in hearing from anyone else with experience.
Angle of attack
You'll hear Greblo speak of it often "AOA" (angle of attack). I'd agree with Eric that a weak link failure with a "higher" AOA is really asking for it.
Also a high AOA can make small things go bad quickly if things get out of hand. Getting "crooked" with a high AOA and you can skew the glider off course really quickly, you'll either end up with the tug pilot giving you the rope, breaking a weak link or worse
Also a high AOA can make small things go bad quickly if things get out of hand. Getting "crooked" with a high AOA and you can skew the glider off course really quickly, you'll either end up with the tug pilot giving you the rope, breaking a weak link or worse
Don wrote;
Notice the significant difference in Jay's agl and glider angle than mine. Surprised
Comments?
Suggestions?
I'm listening.
---------------------
comment
the main dust cloud is behind you no issues there no excuses.bad angle of attack specially on your photos Don.
Suggestion you are not ready for a lightspeed s.you need to practice your angle of attack with a lesser glider like the sports 2 oh I forgot you sold at, but you can have mine if I can take over your purchase on the lightspeed s.
Are you really listening
Notice the significant difference in Jay's agl and glider angle than mine. Surprised
Comments?
Suggestions?
I'm listening.
---------------------
comment
the main dust cloud is behind you no issues there no excuses.bad angle of attack specially on your photos Don.Suggestion
you are not ready for a lightspeed s.you need to practice your angle of attack with a lesser glider like the sports 2 oh I forgot you sold at, but you can have mine if I can take over your purchase on the lightspeed s.Are you really listening
Smile now Cry later
MAX
MAX
Don, Eric;
A stall is just as possible when towing as when not. Stalls have nothing to do with airspeed, only the angle between the airflow and the chord line. Launching at a high angle of attack (but not stalled), when towing, will allow your glider to become stalled earlier and easier in the event of any of the following......
thermals, gusts, small or large dust devils, convergence zones, sudden wind shifts, prop wash, tug vortices, mechanical turbulence, weak link failures, accidental or emergency releases, tug throttle changes, tug engine failure.
On the subject of Jay being closer to the ground, in general, he's actually safer because at his lower angle of attack, his glider has more airspeed, has more retained energy that can quickly be converted to altitude if necessary, has a quicker roll response because less of his span is producing lift, and of course he will not become stalled as easily.
One thing that has not been discussed here, is the airspeed at which the pilot leaves the cart. This can be influenced by the setting of the carts rear keel support, and by the pilot.
Just because the glider can lift off the cart at a given airspeed and angle of attack, doesn't mean you have to leave the cart at that airspeed and angle of attack. Many good tow pilots anticipate the lift off and delay it by pulling in on the control bar before the glider rises off the cart. This is more complicated than it may seem because every glider model has a different pitch pressure and pitch response time, etc. Pulling in too much and you may stay on the cart way longer than you'd like. Not pulling in enough can mean lifting off the cart at a high angle of attack, especially if your gliders airframe geometry makes it sit on the cart at a higher pitch attitude.
Aero tow instructors try to minimize this problem by trying to make sure that the cart is adjusted so the gliders pitch attitude is not too high or too low. You might look at the photos of how the 3 different gliders sat on the cart during the taxi up to launch speed. Also the 3 of you can discuss how much you're each pulling in at lift off. Part of this discussion should include the types of gliders you're flying and how you have them trimmed.
A stall is just as possible when towing as when not. Stalls have nothing to do with airspeed, only the angle between the airflow and the chord line. Launching at a high angle of attack (but not stalled), when towing, will allow your glider to become stalled earlier and easier in the event of any of the following......
thermals, gusts, small or large dust devils, convergence zones, sudden wind shifts, prop wash, tug vortices, mechanical turbulence, weak link failures, accidental or emergency releases, tug throttle changes, tug engine failure.
On the subject of Jay being closer to the ground, in general, he's actually safer because at his lower angle of attack, his glider has more airspeed, has more retained energy that can quickly be converted to altitude if necessary, has a quicker roll response because less of his span is producing lift, and of course he will not become stalled as easily.
One thing that has not been discussed here, is the airspeed at which the pilot leaves the cart. This can be influenced by the setting of the carts rear keel support, and by the pilot.
Just because the glider can lift off the cart at a given airspeed and angle of attack, doesn't mean you have to leave the cart at that airspeed and angle of attack. Many good tow pilots anticipate the lift off and delay it by pulling in on the control bar before the glider rises off the cart. This is more complicated than it may seem because every glider model has a different pitch pressure and pitch response time, etc. Pulling in too much and you may stay on the cart way longer than you'd like. Not pulling in enough can mean lifting off the cart at a high angle of attack, especially if your gliders airframe geometry makes it sit on the cart at a higher pitch attitude.
Aero tow instructors try to minimize this problem by trying to make sure that the cart is adjusted so the gliders pitch attitude is not too high or too low. You might look at the photos of how the 3 different gliders sat on the cart during the taxi up to launch speed. Also the 3 of you can discuss how much you're each pulling in at lift off. Part of this discussion should include the types of gliders you're flying and how you have them trimmed.
I think I look better because I have such a beautiful glider and the helmet hides my old age. Other than that, I felt the pop off the cart. I knew that is a big stress on the weak link so I pulled in to minimize that. The last think I wanted was to have to land proned out with no wheels with a lot of VG in poor visability. I was the first to fly. I set the carts rear support so my wing tips were parallel to the ground. I saw the other gliders sitting in the cart and they looked ok but, that's not to say I'm correct in my judgement. I used half VG. I talked to Kraig about this yesterday. He said many good pilots use that much. More good pilots use less VG. One quarter to one third is normal. I haven't had controlability issues but I am a little heavy on my glider.
eat right, exercise, die anyway!
Max
Max said "Suggestion you are not ready for a lightspeed s.you need to practice your angle of attack with a lesser glider like the sports 2 oh I forgot you sold at, but you can have mine if I can take over your purchase on the lightspeed s.
Are you really listening "
Max - what would YOU do with a Litespeed S ? I thought Greblo didn't allow high-performance gliders at the BEACH
Are you really listening "
Max - what would YOU do with a Litespeed S ? I thought Greblo didn't allow high-performance gliders at the BEACH
Greblo is just so right on. Once the AOA gets too high, controllability becomes compromised, and lockouts or weak link breaks become more likely. Nothing good can come from this combination.
Lower angle of attack, higher speed and closer to the ground is better, until suddently it isn't. Look at it this way: More accidents seem to happen from too high an angle of attack off of the cart than happen from too low an angle of attack. Deal with the most-likely-to-hurt-you issue first, which is too high an AOA.
There is some good towing discussion on the OZ Report, including when to leave the cart. Some disagreement, but largely it is semantic. Pitch control is the key, as mentioned. Not much agreement on the exact time to leave the cart, but almost nobody thinks you should leave it early or with a high AOA.
Lower angle of attack, higher speed and closer to the ground is better, until suddently it isn't.
Look at it this way: More accidents seem to happen from too high an angle of attack off of the cart than happen from too low an angle of attack. Deal with the most-likely-to-hurt-you issue first, which is too high an AOA.There is some good towing discussion on the OZ Report, including when to leave the cart. Some disagreement, but largely it is semantic. Pitch control is the key, as mentioned. Not much agreement on the exact time to leave the cart, but almost nobody thinks you should leave it early or with a high AOA.
Fly High; Fly Far; Fly Safe -- George