REFLECTOR: Pitch Cycling (was Pitch Trim Mystery)

[John Dibble]

Pat,
My cycling is WITH the ap on.  And it is very short cycles (a few secs).  If I
disengage the ap, it goes away.  It only happens once in a while and usually a quick
jab of the stick stops it.  If not, I just fly manually for a while.  Maybe the ap
gets tired.

John

Pat Shea wrote:

> I posted a query a while back about cycling. Flying
> solo and trimmed for level flight, my XLRG has a
> tendency to cycle in pitch. It can settle into 2
> minute cycles with an amplitude of +/- 100'. With two
> people up front this cycling tendency goes away. My CG
> is comparable the most XL's.
>
> What's interesting is that the refecltor replies at
> the time reported negative cycling. I've since spoken
> to multiple fliers who do experience pitch cycling.
> I'm still curious if anyone has been able to combat
> this by means other than using the auto pilot or
> adding ballast up front.
>
> Pat
>
> --- John Dibble <aminetech at bluefrog.com> wrote:
>
> > Scott,
> > Thanks.  That helps a lot.  I was concerned about
> > pitch stability because sometimes my
> > S-TEC ap starts cycling, so I don't want to make it
> > worse.  But if having the strainer
> > inverted provides the same stability, then no
> > problem.
> > Any easy way to remove the strainer without
> > incurring a lot of cosmetic work?
> >
> > John
> >
> > Scott Baker wrote:
> >
> > > Hello John,
> > > Removing the sparrow strainer will cause the pitch
> > control motion to become
> > > more sensitive - but not to the point of
> > instability.
> > > I'm not sure of the aircraft's behavior if the
> > sparrow strainer were
> > > reversed - thinking about it, the upward lifting
> > of the strainer will lend
> > > itself to favor nose pitch down - which left
> > unchecked will result in
> > > greater air speed - which gives more power to the
> > sparrow strainer - which
> > > causes the nose to pitch down some more --- I
> > suppose at some point, the
> > > pitch spring will halt this cycle of events.
> > > SB
>
> __________________________________________________
> Do You Yahoo!?
> Tired of spam?  Yahoo! Mail has the best spam protection around
> http://mail.yahoo.com
> _______________________________________________
> To change your email address, visit http://www.tvbf.org/mailman/listinfo/reflector
>
> Visit the gallery!  www.tvbf.org/gallery
> user:pw = tvbf:jamaicangoose
> Check new archives: www.tvbf.org/pipermail
> Check old archives: http://www.tvbf.org/archives/velocity/maillist.html