A guy at my flying field has this exact model but with an OS 91 four stroke.

He describes it as having good flying characteristics at speed, but a vicious tip stall. Also he said the structural integrity of the body was suspect - could it be that the wing flexibility you mention is also an indicator of suspect design/build?

Like a lot of pattern planes the swallow has a straight trailing edge and swept leading edge.

This will have a number of effects aerodynamically and strcuturally. E.g. for the same wing area/AR, a tapered wing will have a larger chord at the the root - this would normally mean a deeper section - which is structurally stronger than a non-tapered wing with the same AR and area.

Aerodynamically, the lower reynolds number of the tip section on a tapered wing may induce a stall which progresses from the tip rather than the root. If you check out Low RE lift/alpha polars you can see that some sections don't perform well at the Re of a typical model stall - i.e. full-size planes may get away with more taper before a nasty tip stall than the models we fly.

The wing of the swallow is effectively a tapered wing with moderate sweep. Sweep has a stabilising influence equivalent to dihedral - except of course it will work upside down too!
So this will help these pattern planes track smoothly during manouvers - earning them more points in competitions.

Also aerobatic ships should be capable of snapping on elevator - this is built into CAP, Edge, Extra etc. designs - because without a swift spin entry some manouvers are hard to induce on demand.

Swept wings even with no taper have a stall which progresses from the tips rather than root - so the snappiness you are experiencing could be behaviour by design.


However it seems that your Swallow snaps when you don't want it too. My guess is that this could be to do with the finish on the leading edge on the wing.... Is it really sharp? or really round? Sharp will make it snap into a stall more easily, round would be better for avoiding a premature stall.

wing flex could also be a problem however I would expect the wing to flex with induced washout on a swept wing whereas a swept forward wing would flex towards wash-in. and wash-in is tip stall inducing - so maybe your flexible wing is not a culprit.

tricky to know what to suggest. All i can say is keep your elevator travel down or put some serious exponential on the elevator stick on your TX.