Vmca

[Shannon]

Of course I must note that my single engine performance increased by a good little margin with P-tips. I found they gave me a little extra umph for straight and level single engine flight. You can literally feel a better "pull" whereas with carbon props you could feel the "sink". The key is the slightly higher forward speed P-tips enable which helps to keep the ruddervators more effective.

As I've said before you must have good running engines to get anything extra from P-tips. In the past guys have complained that they saw no real difference in performance with their P-tips than with their original Bi-props. It's worth nothing that these were the same guys who had no idea how many hours were on their engines, when the engines were last rebuilt, when the engines last had rings, or even how to go about properly adjusting the engines.

Note: It was discovered a while back that Prince was producing some Lazair Rotax props that were not quite right (slightly over-pitched). These props only allowed the engines to turn up around 4500 rpms static which is unacceptable. A good set of P-tips should allow the engines to turn up around 5,000+/- static on standard bore engines in good condition.

[Shannon]

On a related note a Lazair with a nosepod will see an increase in single engine performance. We found that adding a Pod (Mikes) and even with Bi-props single engine performance increased by a notable margin. Nothing drastic but an improvement is an improvement.

On this plane (with pod and Bi-props) single engine performance was as good as or maybe slightly better than an open-air Lazair equipped with P-tips. Again being able to maintain a slightly higher single engine speed is what makes the difference. You are able to maintain directional control with less ruddervator input straight and level.

[ozzie]

G'day All
something that may be of interest to you is a disscussion on V tails and their controllability going on at the moment on yahoo moni groups.
interesting comments on side slipping at low speeds, may or may not be entirerly revelant to Lazairs but interesting.

regards
Ozzie

[Shannon]

Thanks for the info. I'll check it out.