Today's Message Index:
----------------------
1. 05:12 AM - Self-disassembly of outrigger OR12 spring fitting? (Glenn Rainey)
2. 09:03 AM - Drop in RPM/Mag drop (Hans Joergen Danielsen)
3. 11:02 AM - Re: Self-disassembly of outrigger OR12 spring fitting? (Fred Klein)
4. 01:10 PM - Re: Drop in RPM/Mag drop (pestar)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Self-disassembly of outrigger OR12 spring fitting? |
This is strange.
Hopefully attached to this posting is a picture of the starboard outrigger
mechanism as we found it on preflight yesterday; ops were cancelled due wx,
and also due to uncertainties about this discovery.
The stiffnut normally securing the rearward part of OR12 spring is only par
tially threaded onto its bolt, and finger loose. The AN960-10L washer is mi
ssing, and OR12 hangs from one end.
An engineer in our group also inspected the locknut and found it satisfacto
ry on a new bolt. The original bolt awaits closer examination, however a ne
w fresh nut was secure when attached to it.
These parts would potentially be missing in any accident investigation sear
ch.
I cannot understand how a stiffnut can come undone in this installation. Th
is assembly was fine when inspected one week earlier prior to a test flight
, during which the gear needed cycling once to achieve an outrigger- retrac
ted green light indication. It was not examined post flight then, but the
aircraft was subsequently unattended.
If we hypothesize that perhaps the washer was missing from the original ass
embly, methinks unlikely, then could the thing manage to self-disassemble i
n the course of one short flight with two gear cycles?
I can think of one _possible explanation for this which is a worrying one,
but perhaps other folks have ideas? No maintenance was needed or carried ou
t on this part of the airframe in recent time.
Glenn Rainey / Martin Burns
G-OJHL
Classic monowheel
Scotland
* my second attempt to post, perhaps the image is a problem. Can anyone hel
p with image posting / hosting?
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Drop in RPM/Mag drop |
Engine Gurus!
The engine (914) of the Europa I built, and subsequently sold is not up to acceptable
standards. The new owner experienced a drop in RPM combined with a cracling
noise in the head set. The Flydat also went temporarly black. He was barely
able to maintain altitude and on return to the airfield he switched on the
secondary fuel pump. After awhile the engine regained power. In the heat of the
moment he forgot to check the fuel pressure when the engine was faltering.
During investigation we experienced a slight delay on initial switching of the
fuel pump - till we heard the familiar sound of the pump. During later switching
everything was normal.
We have tried everything - jigling contacts with pump running, changing to another
switch on the panel and even checked the battery itself, to no avail. We are
about to run out of ideas.
This may be a separate snag in itself. When running the engine the Mag drop was
unaceptably high - 400 rpm on Left and 300 rpm on Right magneto. We regapped
the plugs to 0.70 mm, but no effect. We noticed though that both plugs on Cylinder
1 were black with soot while all the others were normal grey. After cleaning
the plugs and running for a few more minutes, the plugs got all black again.
What could this be - a compression leak? I am ruling out the carburetor, since
the plugs on the other cylinder on the same side - which is being fed from
the same manifold - was normal grey.
I'm tossing out these problems to all you knowledgeable people in the group. Any
with a good advice??
Cheers, Hans - ex LN-HJD
<pre><b><font size=2 color="#000000" face="courier new,courier">
</b></font></pre></body></html>
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Self-disassembly of outrigger OR12 spring fitting? |
Glenn...as someone still in the throes of building, I feel it would presumptuous
to offer an opinion on how this situation evolved other than to note that the
AN960-10L washer serves a critical purpose between the sleeve and the stiffnut,
and that the profile of the stiffnut may suggest at first glance that a washer
is in place when in fact it is not.
On a previous post-flight inspection, unrelated to our Europas, I was utterly astonished
to learn how quickly a bolt (once unconstrained) can back out from its
threaded receptacle just from the subtle vibrations of a VERY short flight...
Fred
A194
On Apr 8, 2013, at 5:04 AM, Glenn Rainey wrote:
> This is strange.
>
> Hopefully attached to this posting is a picture of the starboard outrigger mechanism
as we found it on preflight yesterday; ops were cancelled due wx, and
also due to uncertainties about this discovery.
>
> The stiffnut normally securing the rearward part of OR12 spring is only partially
threaded onto its bolt, and finger loose. The AN960-10L washer is missing,
and OR12 hangs from one end.
>
> An engineer in our group also inspected the locknut and found it satisfactory
on a new bolt. The original bolt awaits closer examination, however a new fresh
nut was secure when attached to it.
>
> These parts would potentially be missing in any accident investigation search.
>
> I cannot understand how a stiffnut can come undone in this installation. This
assembly was fine when inspected one week earlier prior to a test flight, during
which the gear needed cycling once to achieve an outrigger- retracted green
light indication. It was not examined post flight then, but the aircraft was
subsequently unattended.
>
> If we hypothesize that perhaps the washer was missing from the original assembly,
methinks unlikely, then could the thing manage to self-disassemble in the
course of one short flight with two gear cycles?
>
> I can think of one _possible explanation for this which is a worrying one, but
perhaps other folks have ideas? No maintenance was needed or carried out on
this part of the airframe in recent time.
>
> Glenn Rainey / Martin Burns
> G-OJHL
> Classic monowheel
> Scotland
>
> * my second attempt to post, perhaps the image is a problem. Can anyone help
with image posting / hosting?<Image1.jpg>
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Drop in RPM/Mag drop |
Hans
I have a 914 but not experienced enough to comment however suggest you post this
question on the Rotax forum of this group (Matronics). There are some very
learned characters who will be able offer you sage advice.
--------
Peter Armstrong
Auckland, New Zealand
DynAero MCR-4S (Do not shoot me :) ).
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=398176#398176
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|