I hadn't expected the ESP to fly first time because of the guesswork involved in the shape of the trailing edge and a few other factors which were uncalculable.
I was pleasantly surprised then when Mike had made a half scale version and it flew first time. He used the 2 line bridle with angle of attack 10 degrees. He'd made the bridle line attachments to the end of the material in the underskin rather than the front of the nose and that didn't seem to be a problem.

Rather than interpret him I'll quote some of his remarks on construction and the maiden flight.

"Last night I put together a halfscale version of the ESP. I have all the panels sewn together, the circumference bound with a strip (90 kg line sewn inside) and the nose ties fastened. I do not yet have the bridle lines connected........
"It went together rather easily but the final construction method may be somewhat more involved. The shape is recognizable as the item in the graphics on your webpage, even though I have not inflated it yet.

"Not much breeze tonight but I took it outside about 10:30pm. first I just slowly walked backwards with the
bridle rings in my hands. It flew about as good as my NPW5 did the first time! I actually attached the TE
lines to separate rings from the LE lines, and then used a short line joining the LE and TE rings with a third
ring in between for adjustment.

"A couple of observations:
1: the nose consistently wants to collapse downward. I let out the LE lines attached to the nose ties about 1cm (I'm at half scale ... snip...) and this helped a little but it still collapses too easily.

2: I adjusted the TE lines about 2 cm behind the LE ring (I am using the dual line bridle for now) and it flew
off the ground better, but did not seem to affect the collapsing nose.

3:  It seems to be somewhat unstable in directional control, i.e.. it does not appear to respond very well to
moderate pulls on one side or the other to tell it to turn left or right. Once it does start turning it doesn't
want to stop turning easily either. I attached about 2 m of line to each side bridle and tried to fly it on
these SHORT lines by walking backward. The ESP did take off from the ground easier than my NPW5. It
appeared to fly more stable when I had my arms stretched out to the sides as far as they would go but the
nose then had a slight V shape with the center panels dipping down slightly at the LE. I think the center half
or maybe 1/3 of the LE need to have longer bridle lines, I will test this later this weekend. First I will see if
shortening the LE of the wingtips has any effect since I have about 2 cm adjustment room to shorten and I
have already max'd out the nose bridle length without retying my loops in the bridle lines.

5: It appears to have a bit higher aspect ratio than the NPW5 which is probably why it doesn't respond to
turning commands as readily. This may change when I pull in the wingtips a little.

4:  Interestingly, the wing tips still have the bulges or waves, characteristic of the NPW5."

Tel: Since then we've exchanged some mail and I'm confident enough to proceed with mod 2 while we try out a few things on Mike's wing to try to improve it.

The basic problem seems to be the nose folding but this doesn't really surprise me either. Remember I'd guestimated the TE flaps. To be on the safe side I underestimated so it would be easier to pull in (or put in a tuck) than let out. The width of the nose is also greater than the NPW's. Here I was hoping that the greater wing area would take care of this but the combination of te flaps and wider nose has led to the nose fill problem, I believe.
Mod 2 will have a nose only a little wider than the NPW and a redesigned te.
The other problem of turning seemed to decrease with increasing wind but there hadn't been much wind to try it in so I'd rather wait before we judge it. Whether we can get a good turning ability and stability without a keel remains to be seen.

Looking closely at the te of the original you can see (the blue line) that it stops at zero at y = 100 and there isn't really a lot to prevent air from spilling out. Mod 2 will be as in the red line. I've changed the rear ellipse marginally and continued it for 1.5cm. This little extra takes the skin angle to 90 degrees and will prevent a lot of spill. On the plans for this one I'll mark the extension in half cm increments so that it will be easy to experiment and chop off or fold over this much (with not too much unpicking required) rather than trying to pull it in with the bridle if needed.
 
 
 
 
 
 
 
 
 
 
 
 
 

From this comparison you can see that the change in the ellipse is not a lot. This is hardly going to affect the centre of lift and bridle tow points (which seems to be about right) but may mean we can reduce the angle of attack slightly.
 

Mike changed the bridling a little moving towards a higher angle of attack (aoa) then added these comments
"The ESP did take off from the ground easier than my NPW5. It appeared to fly more stable when I had my arms stretched out to the sides as far as they would go but the nose then had a slight V shape with the center panels dipping down slightly at the LE. In the stronger breeze tonight the ease of turning was better."

Tel: This prompted me to do another bridle calculation. I moved the tow points out a bit and changed the aoa to 15 degrees.

Mike: "Interestingly, the wing tips still have the bulges or waves, characteristic of the NPW5."

Tel: This may well be inevitable. We are trying to fill a soft bag which is only tied here and there.
We're now waiting for more wind.

More later.