I have flown inthe rain with the standard setup=2C while rturning from Oshk
osh. I didn't notice any problems. But normally I try to avoid it=2C becaus
e it isn't good for the propeller.
Karl
From: sidsel.svein@oslo.online.no
Subject: Europa-List: 912S - Flying in rain
Date: Tue=2C 8 Jun 2010 18:13:07 +0200
The current thread on combustion air=2C ram pressure=2C where to place the
air intake=2C etc. brings up the issue of flying in rain with the Europa eq
uipped with the 912S=2C having the air intake arranged as a NACA duct on to
p of the cowling and the plenum box just below the opening. There are two
3.3 mm (1/8=94) drain holes at the bottom of this plenum box=2C which will
be able to drain away some water intake (you must fly with the ball in dead
center for both to be effective). A certain air pressure build-up in the
plenum makes the drainage more effective.
One theory I have heard goes as follows: If the engine were stopped and su
rrounding air passed over the cowling at a speed of say 120 knots=2C very l
ittle rain would enter the air box. The air would be backed up in the NACA
duct and =93new=94 air and rain drops would for the most part pass over it
. Given this starting scenario (the aircraft moving at a speed of 120 knot
s): If you now have a running engine it will still not suck in so much com
bustion air that the velocity through the NACA duct is anywhere close to 12
0 knots + propeller slip stream velocity. Air would therefore still be bac
ked up in front of the plenum intake=2C with a certain amount of the air an
d rain drops flowing over the inlet.
Theory and reality are two different matters also in this case. What has b
een experienced when it comes to flying this configuration in rain (drizzle
=2C light=2C heavy) ' is it definitely to be avoided or is it more a matt
er of vertical and horizontal visibility?
Regards=2C
Svein
LN-SKJ
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