H_Zwakenberg wrote:
Hi Group,

if you're building your own plane AND you're thinking of installing
anything but a direct drive engine prop/engine system (i.e. a redrive,
drive train, whatever), I urge you to read on:

Donald P. Hessenaur - an engineer who worked at companies like Bede,
RotorWay, Avian and others - wrote a paper about 'Propeller Drive
Systems and Torsional Vibration'. This paper influenced my thinking
about what engine/prop choices I have for my RJ.03 IBIS homebuilt
aircraft project in a major way.
snip

Download it, read it, study it. Be informed! For my canard project,
I've decided to go for a direct drive solution.


If you want the "proven solution" buy a direct drive air cooled
aircraft engine with its lawn tractor ignition and induction-attached
to a production aluminum or tube-and-rag airframe.

If you want to experiment, why experiment with unconventional airframe
designs when airframes are way ahead of propulsion systems in this
market? We have a conucopia of flying airframe designs to suit most all
buyers but relatively few powerplant choices with any substantial
demonstrated success rates.

In another few years,European autoderivative and other diesels will
kill the LyCon export business completely, and third parties will be
undercutting Lycoming on parts so badly that Lycoming is probably going
to die. The Europeans will probably continue the PFM tradition of not
selling to homebuilders. As far as I am concerned there are only two
possible powerplants for homebuilts, autoderivative engines with
US-based parts support, and the P&WC PT-6 series of turboprops. The
Allison 250 I tend to discount because the main versions available tend
to be helo variants and making them work in a fixed wing aircraft
requires what Soloy did-and Soloy is not in the homebuilt business
either. The 331 Garrett and the J-69/Turbomeca centrifugal flow
turbojet (Marbore??) are too loud to be allowed on civilian ramps as
far as I am concerned.

Make no mistake, I will shed no tears at the boarded up windows at 651
Oliver Street.