Flight video of Curtiss HS2L sub hunter in Feb 2020 RCM&E

[Jon Harper]

I thought some might be interested in the attached flight video by my friend Chuck which was the second flight of my 1/12 scale Curtiss HS2L.

You will see that it flies very well off land. Later flights from water were very pleasing as well.

Watch the video to the end and you will notice a change in the motor sound when two things happened. 1- a battery cel voltage sagged. 2- the motor mounting table shifted. Both of these occurrences caused a significant loss of thrust, resulting in a tip-stall as I tried to turn away from the forest.

Lesson learned: Glue the struts supporting the motor table, ensure all batteries are fully charged and balanced, always keep some throttle on, even on landing.

Happily there was little damage, and since then, the plane has flown very well from water too.

Yours, Jon Harper

Video link below

**LINK**

[David Ashby - Moderator]

Hi Jon, I've embedded it below. Lovely model 

Edited By David Ashby - Moderator on 23/01/2020 09:24:58

[Jon Harper]

Thanks David. It was really interesting to design, build, and fly. It is odd how noisy the pusher prop is because it has to cut through the air turbulence coming over the wing. There is tremendous drag and lift so the difference in air speed between 3/4 throttle and 1/4 throttle is not a lot. No loops or rolls for this plane

[Jon Harper]

This image by Chuck, gives an idea of the amount of rigging, flying and control wires that create super drag fighting the lift. This is why there is little speed difference with throttle settings.

jon

Edited By Jon Harper on 23/01/2020 20:12:04

[Jon Harper]

Flying from water, I learned not to decelerate too quickly for fear of being swamped for the rear.

Also notice the stick that could have holed the hull!  Another photo by Chuck.

Jon

Edited By Jon Harper on 25/01/2020 14:52:07

[Jon Harper]

A big bounce, and lift off. Lesson learned: rough water and high winds are a challenge. Wait for calm weather.....

[Jon Harper]

We just tried flying the HS2L in the snow and had 5 good flights. It was a little too windy at 10km/h which required a lot of stirring of sticks. Flying from snow with a boat plane is a lot of fun.

[fly boy3]

A beautiful model indeed. A superb build and video that show the model off at its best. Thanks for the link. Cheers

[fly boy3]

A beautiful model indeed. A superb build and video that show the model off at its best. Thanks for the link. Cheers

[Don Fry]

Lovely thing. For info, it's a tad 6 foot span, I looked it up, so a fair lump of a machine.

[Jon Harper]

Thanks guys. It was a challenging fun build, even better that it actually flies. Don you are right it is pretty big. Photo attached should give an idea of the model size. Ignore the overly large man in the picture, that is me.

[Pete Collins]

Hi Jon

What a beautiful model!  I noticed in the video that it seems to be dragging its tail a little in the turns.  A little rudder mixed in with the ailerons may help.  It could also be an indication of a slightly rearward CG - might be worth investigating.  With the high thrust line it will be pitch up when the power comes off making it prone to tip stalls - as you discovered!  A more forward CG may help.

[Jon Harper]

Thanks Pete, good ideas.   Will investigate by moving the CoG slightly forward.  The rudder aileron mix is a good idea.   I have been trying to remember to to this manually but it usually takes the model tail drooping for me to remember to feed in some rudder.