Auto Towing a 1-26

On Wednesday, August 9, 2017 at 7:07:34 PM UTC-4, wrote:
I'm a new glider pilot looking at purchasing a 1-26.

I'm looking at gaining the flights and experience to get the Commercial Glider and adding the CFI-G to my existing CFI-A.

I envision doing auto tows at my local 3200ft airport. I'll hopefully be getting to 600AGL to just do laps around the pattern. I'd plan to use a 1000ft rope and my 8.1L Chevy Suburban.

What's everyone's take on auto towing a 1-26 mostly just for the fun of very quick flights? Do I need a logbook endorcement for ground launching?

Back in the late 70's we did auto tow at the old Kendall Gliderport in Miami. The tow vehicle was an old station wagon and we used a steel wire along with a weak link. We could get high enough for a pattern tow and several of us were able to get the rating at that time.

You can auto tow a 1-26 or a 2-33 using the "chin" hook, but you'll need a long runway and rope. We could get around 800 feet using a 1200 ft rope on a 5000 ft runway at Odessa, and up to 1200 ft using a 2000 ft wire on a 9000 ft runway at Hobbs. If the glider bucks a little, which it will, release the back pressure on the stick to stop it. I wouldn't try it on a 3000 ft runway.

On 08/12/2017 08:56 AM, Dan Marotta wrote:


On 8/11/2017 6:10 PM, wrote:
On Wednesday, August 9, 2017 at 7:07:34 PM UTC-4,
wrote:
I'm a new glider pilot looking at purchasing a 1-26.

I'm looking at gaining the flights and experience to get the
Commercial Glider and adding the CFI-G to my existing CFI-A.

I envision doing auto tows at my local 3200ft airport. I'll
hopefully be getting to 600AGL to just do laps around the pattern.
I'd plan to use a 1000ft rope and my 8.1L Chevy Suburban.

What's everyone's take on auto towing a 1-26 mostly just for the fun
of very quick flights? Do I need a logbook endorcement for ground
launching?
Sign over your life insurance policy to me first...

Why do you say that? My former partner and I used to take our LS-6a on
safaris all over the southwest using a 1,000' rope and my 5L Ford pickup
or his Jeep Grand Cherokee (don't know the engine size). We routinely
got 700' AGL, though we did have a CG release.

Just for completeness, in your posting about how safe auto towing is,
maybe you should mention how your safaris came to their conclusion.

Two of three were terrific. I assume you're referring to the crash on
the second safari but it had absolutely nothing to do with the auto
tow. It was simply a botched landing pattern wherein the pilot elected
not to land from a textbook base to final position. He flew almost the
entire length of the runway after flying downwind, base, and final, and
only at the last moment, tried to turn back and land. He spun in within
100 feet of where I was sitting winding up the rope. Given his low
altitude and Monday morning quarterbacking, he should have landed
straight ahead on the remaining runway and probably run off the end.
But that would have saved the glider from being destroyed and him
spending a long time in rehab for a broken back.

Hardly an unsafe ground launch. He got off at the normal 700' AGL.

On 8/17/2017 4:36 PM, kinsell wrote:
On 08/12/2017 08:56 AM, Dan Marotta wrote:


On 8/11/2017 6:10 PM, wrote:
On Wednesday, August 9, 2017 at 7:07:34 PM UTC-4,
wrote:
I'm a new glider pilot looking at purchasing a 1-26.

I'm looking at gaining the flights and experience to get the
Commercial Glider and adding the CFI-G to my existing CFI-A.

I envision doing auto tows at my local 3200ft airport. I'll
hopefully be getting to 600AGL to just do laps around the pattern.
I'd plan to use a 1000ft rope and my 8.1L Chevy Suburban.

What's everyone's take on auto towing a 1-26 mostly just for the
fun of very quick flights? Do I need a logbook endorcement for
ground launching?
Sign over your life insurance policy to me first...

Why do you say that? My former partner and I used to take our LS-6a
on safaris all over the southwest using a 1,000' rope and my 5L Ford
pickup or his Jeep Grand Cherokee (don't know the engine size). We
routinely got 700' AGL, though we did have a CG release.

Just for completeness, in your posting about how safe auto towing is,
maybe you should mention how your safaris came to their conclusion.

--
Dan, 5J

Congratulations on getting the glider rating! Your 1-26 auto towing goal sounds reasonable. You do need some additional study and training with documentation of the requirements n the regulations from a CFIG and an endorsement for ground launch from the CFIG.
We get about 600 ft. consistently auto towing our club 1-26E in low head wind conditions at our field, a bit higher if towing into a 10 kt. headwind. Our field elevation is 800 ft. MSL and we have about 3000 ft of usable runway. It gets quite hot in the summer, about 100-110 deg. F. in the summer, so the density s;titude gets a lot higher then. It's a dirt surface, and we use 1100 ft of 1/4 poly twisted rope. It's rated at 1100 lbs breakng strength when new, but obviously gets lower ib strength with age, UV exposure and wear. We use various tow vehicles, depending on who we can cadjole to volunteer. Yours should be more than adequate for the task, and will towca 2-33 with two people in it adequtely also. We use handheld vhf aircraft radios for communications on the CTAF frequency. We have a Schwizer release on the tow vehicle mounted on a heavy gat hinge that can pivot up and down so the release remains in line with the direction of the force on the towline. There is an eye on the moving part of the hinge that keeps the release line in lined up with the releaxe in the proper directo

Sorry for all the typos on prev. post. Cellphone, no spell checker. We found it not necessary or desirable to use a pilot chute or disk to increase drag on glider end tow rope as it falls after glider releases off an auto tow. We let the rope fall in a heap. We do put a streamer of fuorescent colored plastic tape on the glider end in order to identify it for retreival. The rope pulls out during retreival without getting tangled if it is pulled out the same way it fell into the heap. The fast fall without drag producing devices on the rope gives it less time to drift off to the side of the runway in a crosswind. Fortunately, we have a very wide runway with no lights or fences to worry about. A "strop", shich can be made out of 6 ft. of garden hose over the glider end of the rope is a good idea to help reduce the chance of the glider over-running the rope when the tow vehicle takes the slack out of the rope, jerking the glider forward slightly and then hits the, brakes and stops. This can result in the rope getting it tangled around the back end of the skid or in the wheel well, making it so the glider cannot release, and possibly making the back release mechanism inoperative as well.

We have only used the standard Schweizer chin hooks for auto towing 1-26s and 2-33s. We have auto towed Standard Libelle, Diamant 18, and DG 100 with CG hooks over the years. The Schweizers undoubtedly could get somewhat higher if they were equipped with a CG hook. The chin hooks do result in a tendency where the horizontal tail will stall if the pilot pulls back hard on the stick beyond a certain limit. When the tail stalls, it rises, thus pitching the nose down, and actually reducing the angle of attack of the wing. With experience, pilots learn to pull back on the stick to a point just short of inducing this tail stall, which can give the maximum performace climb. If the pilot does not ease off the back pressure and persists in pulling back, a repetitive series of tail stalls, each wth a with pitchdown, followed by the nose pithing up again when the horizonral unstalls, and then as the stick is held back, and then a new tail stall and the resultant ,pitch down. This "bucking" phenomenon is not really dangerous as long as the glider is within design limits of airspeed for ground launch and is otherwise structurally sound ( probably does cause some unecessary fatigue loading to the structure, however). In fact, it might even be considered a usefull feedback signal to the pilot to back off some on the back pressure until the bucking stops, and to check and be sure airspeed is within safe limits. With a CG, hook you don't get the bucking, and can trim the glidet to almost fly the tow by itself in pitch, but you also get less feedback through the back pressure on the stick as to how much loading is being applied to the wings. We generally try to target an appropriate airspeed for a good climb for that particular glider under the conditions of that particular flight, not too fast, which requires lowering the nose to reduce the load on wing and possibly even releasing if at or approaching max placarded auto/winxh airspeed, and not too slow, where a hard pull up would increase risk of stalling the wing near the ground. We use target airspeed of about 50 mph for the 1-26, and about 55 for the 2-33 with 2 occupants. We make an estimated allowance based on the wind speed and wind shear for the tow vehicle driver's initial groundspeed. From there we can make further adjusments for tow vehicle speed using radio communication or between flight debriefings as conditions may change. We never attempt ground launch with any downwind component in wind direction, even in what seem like very light winds on the ground. Any wind shear in a down wind launch will have a very negative effect on climb performance, which is not good if your runway lenghth is relatively short to begin with. "Tension controlled" launches as have been discussed in Soaring Magazine in winch launching articles would undoubtedly be ideal also for auto tows, if not so much for safety as for achieving maximum launch height dor the given runway length and wind conditions. However the tow vehicle determined airspeed target method seems to work well enough, and had a long record of use. Tension controlled auto towing would require much more complicated set ups and a lot more sophisticated testing than what seems practical for our club. We usually reserve auto towing for winter time amusement and skill expanding training in our club, along with a number of times when our only club tow plane has been down. we generally have not made a routine to have simultaineous ground launch and aero tow operations. We also have very little power traffic, limited to mostly our own fly in glidet pilot club members at our glider club owned field