Date:         Sat, 11 Nov 1995 09:48:16 PST
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         Berry Kercheval <kerch@parc.xerox.com>
Subject:      Re: Tragic story: Wonder what failed? 

>>>Cetin Seren said:
 > When Matt D., his 14 yr. old, me and my 11 yr
 > old went up on the Cessna few weeks back, Matt showed me around the
 > plane.  The propeller was not on the crankshaft -- it was mounted on
 > the shaft of a flywheel-sized gear, which was driven by the gear on
 > the crankshaft....

Yes, some planes have geared propellers. Most small planes don't -- my 
propeller attaches directly to the crank flange. (Beech Musketeer with 
COntinental IO-346 for the curious)

 > Do these do-it-yourself planes with VW engines have the propeller
 > directly attached to the crankshaft?  Would this not be a little too
 > fast?  It figures that the prop would be doing better than 30 revs/sec
 > at 2,000 rpm....

No, this is prety normal.  My plane's engine redlines at 2550 RPM.  Much 
faster than that and the prop tips go supersonic, which is inefficient and 
LOUD.

Life for an aircraft engine is often pretty easy, for all they run at near max 
power all day long.  "Low" RPM. high quality fuel, required regular 
maintenance... 

  --berry

Berry Kercheval :: Xerox Palo Alto Research Center