Bonjour Nigel
Do you know that Airmaster prop uses also Wrap Drive blades?Is there any
risk to find a similar problem ?
It's probably difficult to get a good answer as the total hour flying of
Airmaster prop is very low at the moment
JPN N 273 F-PSLH
Nigel Charles <72016.3721@compuserve.com>@europaclub.org.uk le 13/04/2002
10:41:01
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Objet : NSI CAP140 prop/Rotax 912S
All UK operators of the NSI CAP140 prop/Rotax 912S combination should
already be aware that there is a potential problem with this prop/engine
combination. One UK operator has had a crack appear at the root of one of
the blades after 250hrs operation. The prop had already accumulated 500hrs
with a Rotax 912 without problems. A possible cause for this is described
below and other prop operators may like to take note as the loads on any
prop are increased by the 912S over the 912. NSI now provide blade cuffs
with thicker aluminium to compensate. These stronger cuffs have been
standard since 1998 but are only likely to be essential in conjunction with
the 912S. As a precaution in the UK the PFA strongly recommend that no
Europa with this prop/engine combination flies more than 25hrs until the
upgraded cuffs are fitted.
The higher compression ratio of the 912S is placing greater loads on the
blades during shutdown and on kickback on an unsuccessful start attempt. I
understand that Rotax is considering offering a more powerful starter motor
to reduce the chances of kickback. The PFA is recommending that, on a cold
start, the choke is only pulled out when full cranking speed is achieved. I
would also suggest that it makes things easier for the starter if the prop
is positioned just after a compression point during the walkround before
start. The motor then has more chance to up to cranking speed before having
to overcome the high compression.
I am one of those affected by this and, as my aircraft is approaching the
25hr limit, I will shortly be grounded. My prop has had no problems and
rather than going to the expense ($650 plus international shipping costs)
to upgrade the cuffs for 912S use I am considering changing to the
Airmaster. This is not cheap (current UK price 2840 +VAT). As a result my
very low hours prop could be available for use with a 912 (or Jabiru,
Subaru etc) to get a little more performance. The NSI is electric variable
pitch (but without constant speeding) enabling max rpm on take-off and more
economic and quieter cruising. I am looking to get 1200 for my prop which
is less than half its original price so this may be an economic way for
someone to upgrade from a standard ground adjustable prop.
As it will take 30 days for Airmaster to make and deliver the new prop to
me I am looking for help in keeping my Europa flying in the meantime. To
this end, is there anyone in the UK who has a fixed pitch prop they can
lend me until my new prop is ready?
Nigel Charles
Tel 01380 860620
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