Thoughts about air scoops.

[Thomas C. Weedon]

I had a mid-air this last summer that slightly damaged the nose of my plane.
Eric H. suggested that when I repair the nose, I should add an air scoop
just above the rear bearing of my YS-120FZ. He said that it would help cool
the rear bearings and would improve my top RPM. Guess what? He's right! My
engine had a little more power. The rev's increased about 100 to 150 RPM on
the ground and I noticed an improvement in the verticals. So, now I'm
finishing a new fuse and I'm adding another air scoop over the rear of my
YS-140FZ. I think it will help.
Tom Weedon
  -----Original Message-----
  From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org]On
Behalf Of Adam Quennoz
  Sent: Tuesday, February 04, 2003 8:34 PM
  To: Pattern List
  Subject: Thoughts about air scoops.



  It seems the trend these days are air scoops.  Before a scoop is
effective, the area of the air exit must equal or exceed that of the air
intake thus allowing a positve air flow to occur.  With all the scoops
people are putting on the nose of the aircraft, there must be a pretty good
sized hole somewhere for the air to escape.  There are cheek scoops, chin
scoops and now with the concern of cooling the crank cases, there are scoops
above the engine compartment.  I call them "nose scoops".

  Has anyone thought of making EXITS on the top of the nose above the
engine, and/or exits on the cheeks?  Basically put the scoops on backwards.
The air flowing over the backward facing scoop would actually create lower
pressure inside the engine compartment allowing a larger volume of air to
enter the chin scoop.  The air entering the chin scoop can flow all around
the engine as it makes way to the exits of the engine compartment, and
what's left can flow down the pipe tunnel.

  I'd like to hear what others have to say about this idea.  I'm thinking of
trying it on my pattern plane.

  Regards,
  Adam Quennoz
  AMA 383866
  IMAC 2439
  NSRCA 3546
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