Hi all,
Running a 912 (Classic Europa) for 1250 hrs in the often cold moist air of
the UK with no carb heater has resulted in a reasonably regular indication
of carb icing.
The thing to be aware of is that with the Rotax 900 series engines carb
icing manifests itself rather differently from your Continentals and
Lycomings.
In the case of Rotax it shows itself as the occasional cough or what seems
like misfire as each carb in turn ingests bits of ice shed from the throat.
When it happens (and nowadays I have become quite good at predicting it)the
solution is to warm the core temp of the engine by making it work hard for
two or three minutes. IE open the throttle to climb power. Depending on the
severity of the icing will determine how long it is before getting a
recurrence. I have found that even in moderate icing conditions a period of
at least 20 mins elapses before a need to re warm the engine.
Now to the Rotax carb heater which uses coolant water to warm the carb
throat. Inevitably this will only work effectively if the coolant temp is
kept high enough.
Quite often I have flown Rotax engined A/C where the coolant temp in cruise
drops to 55 or 60 degrees C. In icing conditions, even with a carb heater
installed and low coolant temps I have still encountered carb icing on a
number of occasions.
So to sum up avoidance of carb icing, with or without a heater, it is
essential to keep your coolant (and Oil) temps minimums up around the 90
degree area.
Pete Jeffers
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of G-IANI
Sent: 28 June 2008 08:27
Subject: RE: Europa-List: Rotax carb heaters
Ron
In 250 hour flown in the UK never any sign of carb ice and we have flown all
winter. So, as I have read elsewhere, no need for carb heaters. Same
experience with G-IRON.
Ian Rickard G-IANI XS Trigear, 914, 250 hours
Europa Club Mods Rep (Trigear)
e-mail mods@europaclub.org.uk
or direct g-iani@ntlworld.com
Checked by AVG.
11:20 AM
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