-----Original Message-----
From: Klaus Dietrich <KDIETRIC@AT.oracle.com>
Date: 27 September 1999 11:21
Subject: NSI-VP prop
We both had one technical incident which we would like to report because we
believe it could affect all those with the NSI prop.:
Both electrical wires from the electrical motor to the hub where badly
damaged on their base. After removing the motor/gear combination from the
hub, it turned out that all the four small screws which are holding the gear
box to the aluminium support block from behind where completely loose which
enabled the electrical motor/gear to turn on itself and damaging the wires.
I checked immediately my prop and after removing the motor housing found out
that also here the motor/gear was not firmly fixed on its support but had
some play. After removing the motor/gear from the hub I discovered that also
here two of four the small screws where loose by three or four threads and
the two others by one or two threads. (however, the four small screws which
are holding the motor on the gear box where all tight, on both props)
Those little screws are not secured in any way (no Loctite, no washers, no
safety wire, no cover) and have room to get loose and even to fall out.
A fix of this should be found urgently and all current users should be
advised to check this before the next flight.
Safe flying
Klaus (OE-CKD)
Hi Klaus,
On our prop the screws are wire locked, but I also have found the wires
pulled tight over edges of the fixing flange, this is made worse by having
to keep tension on the wire as you assemble the hub. Also be aware, the
holes in the hub (engine side) where the wires come out have sharp edges as
well, and can cut through the insulation. I have just had to replace both
the wires on our hub.
We have also been very pleased with the performance of our propeller, but we
have a couple of minor irritations. We find the operation becomes
intermittent after about 20 hours due to a build up of carbon on the slip
rings, clean the rings back to bare brass and it works fine again, have you
found this. Also the red limit light is very un-reliable, usually works on
the ground, but more often than not it fails in flight. I have tried
altering the settings on the control box but have never been able to get it
to work properly, how do you find it?
Regards
Jim
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