[MikeLake]

Out of interest what’s the turnaround time for an average launch using your payout system(s)? Or indeed any other towing you might do.

[Bill Cummings]

Hey Mike Lake,
I have some information on turn around times for towing here before we had a website. (Hard Copy.)
I just got back from one of our local flying sites and have to look up flying conditions for tomorrow. (Shamelessly dropping names here) I did the driving duties for Robin Hastings and Canadian national hang gliding champion John Theoret at our Magdalena Rim launch site.
Tomorrow I might be throwing John off of the East Potrillo Mountains into an east wind IF the forecasters are right.

As soon as I can I’ll thumb through some of the old news letters to find the one that I did as editor for the RGSA hang gliding club on that subject as it applied to Quest and Wallaby aero tow operations.
Off the top of my head I would be comfortable saying that turn around times usually can only be averaged due to changing conditions, number of pilots, Montezuma’s Revenge, hang over, cloud base, the variable list is long.
I SHALL RETURN!

[Bill Cummings]

Mike I haven’t forgotten you. I have been sifting through my years of club newsletters but have not stumbled across the turn around times between Quest and Wallaby. These two places I actually timed. I have actually less specifically timed turn around times for my operations except for to say that between my wife and I we served Don Ray of Aurora Minnesota (USA) up, boat towing, 36 times
On a high pressure sled ride day over White Water Lake. This was our record.
I shall return! (1,600 foot rope) I have a bad cold now and have lately been crawling in the whisky bottle and pulling in the cork in behind me. Laters, I hope.
Wish me luck.

[MikeLake]

No sweat. It’s just that I was having a discussion with some aerotow guys about this issue.

This was my post
………………………

“On a good day when the gremlins are too drunk to bother and the ground crew are all sober....

The tow up time will depend on wind strength and the time this gives on tow.
But from release it takes about a minute to reel in and another minute to make sure the spent line isn’t interfering with the good line.

If the ground crew are on the ball the next pilot is ready so another two minutes tops to clip in and launch.
The quad will already be at the winch end as he follows the first pilot down the runway. The two lines are carefully pulled back at 10mph to avoid tangles (something to address) so say five minutes and you are ready for the next two launches.

This is a good day but of course we do have the occasional line break or tangle always timed when the clouds are building.”
………………………

This is our turnaround overhead (note not including the actual launch time).
It got me wondering about other systems. I can’t remember too much from my payout winch days.

[wingspan33]

Hi Mike,

While Bill works at feeling better and finding his detailed info, I may be able to help some. I've been a crew member using an ATOL truck tow system (and been towed up by that method 150-200 times). As a crew member, I've participated in (easily) a few hundred truck tows. An average turn around time (getting the glider on board the truck, then launching, achieving altitude, releasing the glider, rewinding the tow line and returning the truck to the flight line) was in the area of 15 minutes. Lower altitude tows could go faster and "step tows" could go 50% or more longer.

I've also done some aerotowing, but that was a long time ago (mid to late 1980s). If memory serves, from glider set up (as in attaching it to the tow plane) to the tow plane being ready to tow the next person, the turn around time was ~ 15 - 20 minutes. The process was a bit quicker then because we weren't yet using "carts" for the gliders. We simply ran off the ground behind the tow plane. Adding in the use of a cart obviously lengthens the turn around time - but also may not have that much effect. The reason being, having multiple carts available one pilot could be getting their glider prepared on one cart while another pilot is on another cart about to be towed.

Of course, turn around times also depend upon what altitude the pilot is towed to before release. Turn around time for someone being towed to 500 feet is much quicker than someone being tower up to 3,000 feet.

All the tow operations I've been involved with were more informal commercial operations, as opposed to high intensity tow operations. I've seen a good number of videos where (high volume) tow pilots come very close to DIVING out of the sky after they release their tow pilot. Clearly, when you need to make a (bigger) profit turn around times can be made quicker!

Out of interest what’s the turnaround time for an average launch using your payout system(s)? Or indeed any other towing you might do.

[JoeF]

The times under one minute are sought in a proposed new tech:
viewtopic.php?f=2&t=1634
Conveyor-belt wind-powered system; just keep adding OWWs to the conveyor.
Releasing a wing every minute off the top of the loop conveyor?
Maybe 60 HGs per hour? Duplicate the system to say three systems at a field: 180 HGs per hour?
~ JoeF

[Bill Cummings]

I found my turn around times at Wallaby and Quest and also for the Duluth Skyline Sky Dogs aerotow operation that was at Superior, Wisconsin Bong Airfield. (All in USA) Quest and Wallaby were near sea level with Bong Airfield a little above 600’ MSL.

These are pieces from a club article that I wrote for RGSA Club Newsletter in 2003 I believe since I lost the cover page with the date. It was the year of the first ever USHPA sanctioned PG tow meet. (2003?)

At that time Quest was towing pilots to 2,500’ agl for $20.00 while Wallaby was dropping them off at 2,000’ agl for $15.00.
At Wallaby from the time the first pilot started to roll he was off the cart in 3 seconds into a 3 to 7 mph wind. They had the second pilot off the cart in less than 5 minutes. The same tug.

At Quest, tow to 2,500’ agl and with a 2 to 3 mph 90 degree crosswind roll out to lift off averaged 5 seconds. Turn around time was 8 to 10 minutes.

I used to “Black Box,” most of my platform launches so that I would have accurate stuff to put in the log book so maybe I could average some of those turn around times. I’ll see if I can talk myself into doing that.

Oh yes. At Bong Airfield Superior Wisconsin with their smaller 60 hp Rotax motor using a 6 blade composite prop., on the Dragonfly they averaged a 500’/min. climb rate. The temperature was 80 degrees Fahrenheit with relative humidity 60%, 671’ msl, 7 to 10 second roll out before lift off