ORIGINAL: JGrc
Hgiles,
That's correct, in most airplanes when you lower more than 40ยบ of flaps, the horizontal stab doesn't get enough airflow to be effective. It aggravates if you have a heavy nose airplane. In my airplane at least, I would not be able to raise the nose for flair in half rate mode unless I come much faster than necesary. Also we have to remember than not Spitfires models are the same or have being built the same way, so is hard to make a "general" rule.
Peter,
what do you mean by "porpoising on finals"?
JG
I have both a 1/5th scale Hurricane and a 1/5th scale Spitfire. The Spitfires flaps are much smaller, relatively speaking, than the Hurricane. When deploying the Spits flaps (to 85 degrees), the plane lands beautifully. When deploying the Hurricanes flaps to 85 degrees, the landing flare disappears. The flaps are much larger and the tailplane of the Hurricane is smaller than the Spitfire. The blanking of airflow over the surfaces appears to affect the Hurricane much more than the Spitfire. Don't think this was the case with the full size fighters, however, so it seems to be related to the scaling factor