Houston JS1c crash ONLY (not in any way about a Puchaczs, or anything else!)

On Saturday, May 16, 2015 at 8:37:35 AM UTC-4, wrote:
Thanks OG. The JS-1 self launch has been mentioned. Pardon my rudeness for "pinching" you but is the prototype flying?

Ben, I believe the inner wing weight is only a function of where the wing is cut (for the tips). The V2 and 29 inner wing panels are shorter than the JS, hence the lighter weight. Personally, I prefer the handling and ride of the 21m, but I am biassed to longer wings😄

It is not even close to being built.

Meanwhile another Js 1C went down...

http://lotniczapolska.pl/Wypadek-szy...wej-Woli,37381

Slow tow with full water?

On Sunday, May 17, 2015 at 2:43:09 PM UTC+1, Craig Funston wrote:
Slow tow with full water?

I don't know anything about the circumstances but there has been an advisory email to all owners to emphasise the need to make sure that tug pilots are briefed that the minimum aerotow speed for a fully ballasted JS1C/21m is 70 knots (130 km/h) in turbulent conditions. The minimum in calm conditions is 65 knots.

The wingloading of a 21m JS1 at the MAUW of 720Kg is 58.7kg/m2 which is higher than any other glider that is likely to be regularly aerotowed in any numbers. The only other production gliders with similar max wing loadings are the Quintus and the EB29 with its shortest 25.3 tips (which are all self launchers) and the Antares 23T of which there are not likely to be many. It is this unusually high wingloading that needs to be fully appreciated at both ends of the tow rope IMHO.

John Galloway

On Sunday, May 17, 2015 at 3:34:34 PM UTC+1, wrote:
On Sunday, May 17, 2015 at 2:43:09 PM UTC+1, Craig Funston wrote:
Slow tow with full water?

I don't know anything about the circumstances but there has been an advisory email to all owners to emphasise the need to make sure that tug pilots are briefed that the minimum aerotow speed for a fully ballasted JS1C/21m is 70 knots (130 km/h) in turbulent conditions. The minimum in calm conditions is 65 knots.

The wingloading of a 21m JS1 at the MAUW of 720Kg is 58.7kg/m2 which is higher than any other glider that is likely to be regularly aerotowed in any numbers. The only other production gliders with similar max wing loadings are the Quintus and the EB29 with its shortest 25.3 tips (which are all self launchers) and the Antares 23T of which there are not likely to be many. It is this unusually high wingloading that needs to be fully appreciated at both ends of the tow rope IMHO.

John Galloway

Moving away from the subject of crashes momentarily (I hope!) - i'm test flying a JS-1 on Saturday if the weather in the UK is kind. It'll be unballasted and likely in 18m mode. I'm just a little bit excited.

Jim I've got a couple short flights in a dry 18m JS1. You'll be smiling for weeks.

I really dont know what the status is, or when it is expected to fly

Originally Posted by

On Sunday, May 17, 2015 at 2:43:09 PM UTC+1, Craig Funston wrote:
Slow tow with full water?

I don't know anything about the circumstances but there has been an advisory email to all owners to emphasise the need to make sure that tug pilots are briefed that the minimum aerotow speed for a fully ballasted JS1C/21m is 70 knots (130 km/h) in turbulent conditions. The minimum in calm conditions is 65 knots.

The wingloading of a 21m JS1 at the MAUW of 720Kg is 58.7kg/m2 which is higher than any other glider that is likely to be regularly aerotowed in any numbers. The only other production gliders with similar max wing loadings are the Quintus and the EB29 with its shortest 25.3 tips (which are all self launchers) and the Antares 23T of which there are not likely to be many. It is this unusually high wingloading that needs to be fully appreciated at both ends of the tow rope IMHO.

John Galloway

The ASG 29 in 15m has a max wingloading of 59.65kg/m2 according to the EASA TCDS

https://easa.europa.eu/system/files/...2-20022008.pdf

I wonder how well it handles that load on tow

Originally Posted by

On Sunday, May 17, 2015 at 2:43:09 PM UTC+1, Craig Funston wrote:
Slow tow with full water?

I don't know anything about the circumstances but there has been an advisory email to all owners to emphasise the need to make sure that tug pilots are briefed that the minimum aerotow speed for a fully ballasted JS1C/21m is 70 knots (130 km/h) in turbulent conditions. The minimum in calm conditions is 65 knots.

The wingloading of a 21m JS1 at the MAUW of 720Kg is 58.7kg/m2 which is higher than any other glider that is likely to be regularly aerotowed in any numbers. The only other production gliders with similar max wing loadings are the Quintus and the EB29 with its shortest 25.3 tips (which are all self launchers) and the Antares 23T of which there are not likely to be many. It is this unusually high wingloading that needs to be fully appreciated at both ends of the tow rope IMHO.

John Galloway

I've had the experience in my Nimbus 3D of a tow pilot slowing up to try and maintain a positive rate of climb at my home club. Much calling on the radio finally got me some more speed and comfort

I've also had a clubmate recount a tow pilot declaring he was already towing fast enough when he was calling for more speed in his heavily loaded ship while launching at another club.

Both occasions were experienced tow pilots so there was some sort of disconnect going on.

There are 3 JS1s here at the one club in NZ, 2 are JS1-C 18/21 and the other one a B. I must ask of their experiences tow wise when I next visit

Weather looking crappy for my test flight on Saturday but I'm not giving up hope yet. Does anyone have a view on 'time to power' for jet sustainers? I'm not sure how long it takes to get to full power in my Discus bT if I'm honest but I'd guess somewhere around 30 seconds? I believe JS-1 TJ is about 45-50 to full power. Obviously I have more drag and I need to dive to start but I don't know how much time and height loss are factors compared to a jet. Anyone got experience of using a jet to avoid a landout?