Seraph

Can anyone explain why it should be the inside wing which stalls first in a turn? Since the outer wing has a down-going aileron and, therefore an increased angle of attack I should have thought the plane would tend to fall outwards.

If you haven't got a tripod just rest your elbows on the edge of the table while you squeeze the shutter release gently. Of course nobody will be able to tell it was you that took the picture but you can't have it all ways.

Forgive me stating the obvious BEB but I think your chronic photographic problem is not focus but camera shake.

Both antennas horizontal across the fuselage? Doesn't sound right to me. The fact that you had the satellite body vertical isn't really relevant - it's the attitude of the antennae which counts

It doesn't sound like a radio failure to me. Have you checked the elevator control linkage, especially the the screws which clamp the control rod to the servo arm. These can move and then jam if the screw isn't really tight.

Ultimate, you seem to be able to charm the birds down from the trees.

It's definitely a Phylloscopus warbler, either a willow warbler or a chiffchaff. Judging by the dark legs and the muted over all colouring I'd go for chiffchaff.

Thank you Will-o. That is very clear.

I think you, Simon and BEB have provided two distinct and consistent explanations of this. i would now like to ask why, with conventional centre-hinged ailerons (I'm excluding balanced ailerons and Frise ailerons for the moment) you necessarily get adverse yaw. I have been assured that this is simply the consequence of drag being proportional to lift. The lowered aileron results in more lift and, hence, more drag while the raised aileron reduces lift and drag. Is this a correct and complete explanation?

BEB, that's a very simple and elegant geometrical explanation - thank you.

Thank you Simon for your explanation. This is one of those thing which I felt intuitively to be so but couldn't find any theoretical support for. My own rationalisation was that if you could consider the aileron as essentially a thin flat sheet, hinged to the top surface of the wing then it was obviously going to penetrate more into the airflow above the wing than below creating more drag there. But, as one of my old maths lecturers used to say, "Obvious is what I know how to prove" and I don't. That's why I've raised the question here.

I am building a model which has a fairly thick wing section with ailerons hinged along their top edges using the covering film. My question is does this have a similar effect to using differential aileron movement. Or, to put it differently, will the up going aileron produce more additional drag than the down going one, although they have the same movement?

BEB, you meant Momentum is MassxVelocity, of course. However, I would argue that an aircraft will resist disturbing forces by virtue of its INERTIA. Ie. it's MASS. The effect of the disturbing influence will be to change its Velocity. (Pt=mV-mU) Hence the heavier a model, the less it will be disturbed by gusts - so just add weight. That brings us back to the point you rightly made that the heavier model will need to fly faster to develop the necessary lift.

I bought the Shacklock book last year after seeing a friend's copy. I was immediately attracted to the MicroT as I thought it would make an excellent camera platform and it is now completed and waiting for some halfway decent weather to fly. I thought the original plans looked unnecessarily beefy so I have built as lightly as possible. For example I used thinner ply for the body sides and made a lighter tail boom. Having said that, I did make the wings in two parts which are joined using carbon tubes in paper tubes - they go into the car easier than a one-piece wing. The plan gives a flying weight of 5 lbs and I aimed at 3. In the event the completed thing, ready to fly, came out at exactly 4 lbs. It uses an OS OCA150 motor with a 4s 2200mAH LiPo. The tail boom is made from four laminations of soft 1/32 in balsa formed around a 1 1/8 in broom handle, using PVA glue. I had previously used this method for making motor tubes for competition rubber-powered models. This is my first contribution to this forum but hope it will not be the last.