high tow vs low tow

On Tuesday, February 26, 2019 at 10:16:56 PM UTC-5, Ramy wrote:
Sounds to me that this method of staying low in ground effect for low tow position will increase the time we spend in the dangerous zone below 200 feet, in addition to transitioning through the wake while low and slow. Personally I prefer to spend as less time as possible down low, and would rather transition to low tow position at safe altitude and safe speed. Especially at high density altitude such as we have in the west, fully ballasted combined with not so powerful towplane, the last thing I would want is to purposely stay in ground effect at the end of the runway while the tow plane slowly climbs higher. I never tried this, so maybe it is not as bad as i think it is.

Ramy

One reason I will never do this in a ballasted glider is wind shear.

Low tow increases the glider pilot's vulnerability to a slow tow.

best,
Evan

On Wednesday, February 27, 2019 at 7:45:46 AM UTC-5, Tango Eight wrote:
On Tuesday, February 26, 2019 at 10:16:56 PM UTC-5, Ramy wrote:
Sounds to me that this method of staying low in ground effect for low tow position will increase the time we spend in the dangerous zone below 200 feet, in addition to transitioning through the wake while low and slow. Personally I prefer to spend as less time as possible down low, and would rather transition to low tow position at safe altitude and safe speed. Especially at high density altitude such as we have in the west, fully ballasted combined with not so powerful towplane, the last thing I would want is to purposely stay in ground effect at the end of the runway while the tow plane slowly climbs higher. I never tried this, so maybe it is not as bad as i think it is.

Ramy

One reason I will never do this in a ballasted glider is wind shear.

Low tow increases the glider pilot's vulnerability to a slow tow.

best,
Evan

If excessively low on tow wind shear can be a factor. Properly flown, my experience is that it is not.
Possibly you can explain your second contention. Slow is slow no matter which position you are in.
UH

On Wednesday, February 27, 2019 at 8:52:36 AM UTC-5, wrote:
On Wednesday, February 27, 2019 at 7:45:46 AM UTC-5, Tango Eight wrote:
On Tuesday, February 26, 2019 at 10:16:56 PM UTC-5, Ramy wrote:
Sounds to me that this method of staying low in ground effect for low tow position will increase the time we spend in the dangerous zone below 200 feet, in addition to transitioning through the wake while low and slow. Personally I prefer to spend as less time as possible down low, and would rather transition to low tow position at safe altitude and safe speed. Especially at high density altitude such as we have in the west, fully ballasted combined with not so powerful towplane, the last thing I would want is to purposely stay in ground effect at the end of the runway while the tow plane slowly climbs higher. I never tried this, so maybe it is not as bad as i think it is.

Ramy

One reason I will never do this in a ballasted glider is wind shear.

Low tow increases the glider pilot's vulnerability to a slow tow.

best,
Evan

If excessively low on tow wind shear can be a factor. Properly flown, my experience is that it is not.
Possibly you can explain your second contention. Slow is slow no matter which position you are in.
UH

I think your argument here is that "a properly flown low tow doesn't hurt much." In which case my point has been made, yes?

T8

I would say, a "properly flown tow" doesn't hurt much.
There are issues in ANY formation flying, a glider aero tow is formation flying.
Do we at least agree on that (that an aero tow is formation flying)?

Any aero tow (or even winch launch, etc.) has some risk.
I have seen people fly low tow as a "new thing" when they normally did high tow. Common issue is waiting late to climb with the towplane.

As I stated earlier, this discussion has been hashed out on RAS before as well as other places.
To me, this is a "no win" for anyone.
We train for both, which is good.
I normally fly whatever tow is "usual" at a site.

All my early flights were in South Africa, where low tow was the norm at my home field. I only remember one problem, when my heavily-ballasted Jantar-1 over-ran the towplane when it slowed on hitting a strong thermal. The towrope snaked over the canopy then passed over my left wing in a large loop.. I recovered just fine, but it did catch my attention!

I have had many more problems trying to maintain high tow in a fully ballasted Discus 2b and had several occasions where I ran out of elevator authority due to a slow tow, usually releasing prematurely. I managed to stay on once in such a slow tow, but sank into low tow position and had insufficient elevator to resume high tow at the speed flown. Maybe low tow has a slight aerodynamic edge with modern ships?

Mike

So....I think you are bringing up a completely different issue now...the speed of the tow. If the problem is too slow of a tow....the solution is to get the tug to go faster...the solution is not high tow or low tow....

Accepted procedure is for the glider pilot to brief the tow pilot on any pertinent information needed for the tow...such as airspeed to be used...

Many previous discussions on why a glider can fly at a fairly slow airspeed in free flight, yet can't comfortably fly that slow while on tow.

Cookie

On Wednesday, February 27, 2019 at 2:29:16 PM UTC-5, Mike the Strike wrote:
All my early flights were in South Africa, where low tow was the norm at my home field. I only remember one problem, when my heavily-ballasted Jantar-1 over-ran the towplane when it slowed on hitting a strong thermal. The towrope snaked over the canopy then passed over my left wing in a large loop. I recovered just fine, but it did catch my attention!

I have had many more problems trying to maintain high tow in a fully ballasted Discus 2b and had several occasions where I ran out of elevator authority due to a slow tow, usually releasing prematurely. I managed to stay on once in such a slow tow, but sank into low tow position and had insufficient elevator to resume high tow at the speed flown. Maybe low tow has a slight aerodynamic edge with modern ships?

Mike

While I agree that "slow is slow", I think it's much better to be in
high tow position and be able to sink to low tow if the tug gets too
slow.Â* I've been dangling on the end of a slow rope with a full load and
had to start dumping while on tow.Â* It's not comfortable.

Of course that proper thing is to not get slow and I blame this on an
inexperienced tuggie who strives for a good climb rate at the expense of
the glider.

On 2/27/2019 6:52 AM, wrote:
On Wednesday, February 27, 2019 at 7:45:46 AM UTC-5, Tango Eight wrote:
On Tuesday, February 26, 2019 at 10:16:56 PM UTC-5, Ramy wrote:
Sounds to me that this method of staying low in ground effect for low tow position will increase the time we spend in the dangerous zone below 200 feet, in addition to transitioning through the wake while low and slow. Personally I prefer to spend as less time as possible down low, and would rather transition to low tow position at safe altitude and safe speed. Especially at high density altitude such as we have in the west, fully ballasted combined with not so powerful towplane, the last thing I would want is to purposely stay in ground effect at the end of the runway while the tow plane slowly climbs higher. I never tried this, so maybe it is not as bad as i think it is.

Ramy
One reason I will never do this in a ballasted glider is wind shear.

Low tow increases the glider pilot's vulnerability to a slow tow.

best,
Evan
If excessively low on tow wind shear can be a factor. Properly flown, my experience is that it is not.
Possibly you can explain your second contention. Slow is slow no matter which position you are in.
UH

--
Dan, 5J

On Wednesday, February 27, 2019 at 9:30:18 AM UTC-8, Dan Marotta wrote:
While I agree that "slow is slow", I think it's much better to be in
high tow position and be able to sink to low tow if the tug gets too
slow.Â* I've been dangling on the end of a slow rope with a full load and
had to start dumping while on tow.Â* It's not comfortable.

Of course that proper thing is to not get slow and I blame this on an
inexperienced tuggie who strives for a good climb rate at the expense of
the glider.

On 2/27/2019 6:52 AM, wrote:
On Wednesday, February 27, 2019 at 7:45:46 AM UTC-5, Tango Eight wrote:
On Tuesday, February 26, 2019 at 10:16:56 PM UTC-5, Ramy wrote:
Sounds to me that this method of staying low in ground effect for low tow position will increase the time we spend in the dangerous zone below 200 feet, in addition to transitioning through the wake while low and slow. Personally I prefer to spend as less time as possible down low, and would rather transition to low tow position at safe altitude and safe speed. Especially at high density altitude such as we have in the west, fully ballasted combined with not so powerful towplane, the last thing I would want is to purposely stay in ground effect at the end of the runway while the tow plane slowly climbs higher. I never tried this, so maybe it is not as bad as i think it is.

Ramy
One reason I will never do this in a ballasted glider is wind shear.

Low tow increases the glider pilot's vulnerability to a slow tow.

best,
Evan
If excessively low on tow wind shear can be a factor. Properly flown, my experience is that it is not.
Possibly you can explain your second contention. Slow is slow no matter which position you are in.
UH

--
Dan, 5J

I received my glider training in Minden. Some of you might have heard rotor can be a real thing there. From day one I was conditioned, if I ever lost sight of tow plane to release immediately, and I have! Other than training the only low tow I have been in was back in the 90's we (local not Minden) had a string of very poorly (not) trained tow pilots. It was so bad pilots were making signs that said "Fast tow". To this day there are no radios in the local tugs I was flying a loaded ASW-24 and was so slow and low that the tow rope was basically just inched in front of the leading edge (CG Hook). Thank goodness for the Nixon/Murray water system, dumps fast. Since this tow pilot was towing away from field low and slow, I to wait until I thought I could make it back to airport before I released. On the ground I spoke to the tuggie. He had no clue gliders carried water ballast. I held up a sign that said I had water ballast before the tow he thought that was drinking water! That same day he towed a 1-26 at 70 knots straight away from airport with no mind of return to airport for the 1-26 driver. Since I got back into gliding our tow pilots are some of the best pilots of anything I have ever met! Perhaps all this boils down to improper initial training. If I was sleeping, dreaming of being on tow, and in the dream lost sight of tow plane, I would still be pulling for that release. Of course I don't mess with anything else on tow because I have been trained while flying tow, that is the only thing you should be doing!

In Minden before each training session we briefed the tow and we briefed immediate release if lost sight. It was much more than cursory, or something we mentioned a few times, it was part of every before flight emergency procedure spoken outloud.