ORIGINAL: David Ingham
I have been re-reading Model Aircraft Aerodynamics by Martin Simons, 1978, because I have a copy. It has some nice data and tells much about what was common practice, but sometimes draws wrong conclusions.
He concludes that there is no aerodynamic advantage to combining the stabilizer and elevator into a stabilator, because he misses the way these work together and just considers the effect of the elevator.
David,
I've just been re-reading Simons book. Thanks for bringing it to the attention of everyone. I forgot how thorough and useful it is. Going through it again has reminded me of a lot of the details that aren't often of day to day importance. And his coverage of the basics is worth the time for any beginner.
As for his conclusions about the two types of horizontal tail, I think they're fairly well summed up by a couple of sentences in the section that compares the two.
"Since the pendulum elevator [i.e. the stabilator]
is more effective, it can achieve the same result by moving through a small angle. If for example, the symmetrical profile is shifted to an angle of attack about 5 degrees, it will be as effective as a hinged flap at 10 degrees. Even this small movement takes the symmetrical profile out of the low drag range, which is quite narrow on the thin aerofoils normally used for tailplanes." He goes on to compare the values of the stabilator and the problems encountered when using it on models. Unfortunately, he only touches on that subject in slightly less than a page.
The book is basically an excellent one for modelers who want to understand more about the aerodynamics of models. It would make an excellent text book for schools, if any ever decided to offer courses in model design (fat chance of that happening). Even experienced aero-geeks would benefit from reading it. For example, his section on Longitudinal Stability shows why the horizontal tail should be considered when computing CG ranges.
It's a really good book for sure.