I don't like to see Tony K getting all this flack, (although I enjoy
watching the fireworks) so I'll divert some of the fire by sticking my nose
above the parapet. First of all the Airmaster test aircraft which Tony
flies is a bog-standard Europa Classic bought from Australia, although
nicely made (I have seen it). It has more sophisticated test equipment in
it than you would be wise to shake a stick at, and Tony flies mainly in the
early morning when conditions are calm and non-thermal. I have flown in
four or five different Europas, all with 912's, and their performance has
differed markedly. Some very fast Europas exist although none of them have
contributed to this discussion. I sometimes wonder how many Europas, when
trimmed for level flight in the cruise, have tailplanes flying out in a
straight line, and how many are undulating, because the angle of incidence
at which they have been set isn't actually the optimum given the possible
other vagaries in the rigging of the aircraft. I personally believe Tony's
figures, because I know he has gone to endless lengths to verify them.
As regards "on the step", Fred F omitted one vital component, airspeed.
There can be no doubt that you can fly level at two different A of A with
different power settings, The question is whether you can do this at the
same airspeed. Might I suggest that if you are coming up to your cruise
speed from a climb you have the propellor thrashing around possibly
upsetting the lift of one or both wings, while if you dive down to attain
your cruise speed, and particularily if you have a variable pitch prop, you
may have smoother flow over the wings, a lesser A of A and less induced
drag. Just a thought, but there is often more than a grain of truth in
urban myths or old wives tales, even is science is sometimes a bit slow to
reach the same conclusion.
Frank Mycroft
|