2005 Masters maneuver #4 - Warning

[John Pavlick]

Hey, my Bridi UFO has no problem with it...  Maybe it's the anhedral stab...
Just kidding.
John Pavlick
http://www.idseng.com


  -----Original Message-----
  From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org]On
Behalf Of Mike Hester
  Sent: Friday, January 07, 2005 9:08 PM
  To: discussion at nsrca.org
  Subject: Re: 2005 Masters maneuver #4 - Warning


  Well, when the wing in question has tubes thinner than tissue and no
proper end support, you'll have that.

  Be careful guys, watch that covering for buckling. We've seen quite a few
lately around here with this same problem.

  -Mike
    ----- Original Message -----
    From: Cameron Smith
    To: discussion at nsrca.org
    Sent: Friday, January 07, 2005 8:39 PM
    Subject: RE: 2005 Masters maneuver #4 - Warning


    SAME THING ON MY HYDE-A-WAY!! I installed a larger False Rib from the
bottom & used Elmers Polyurethane on Foam areas! Cause it swells & fills any
Voids in the foam areas. Don’t get any in your sockets!!

       Now back to trying to get a C O N S I S T A N T  Snap!



    -----Original Message-----
    From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org]
On Behalf Of Grow Pattern
    Sent: Friday, January 07, 2005 7:40 PM
    To: discussion at nsrca.org
    Subject: 2005 Masters maneuver #4 - Warning



    This is a sort of public service announcement, or at least please regard
it as a "Heads-up".



    For all of you who are flying or will be flying the Reverse Avalanche
you might want to check your wing tubes and phenolic tube wing supports.



    It seems that if you go into the snap a bit hard you can bend your wing
tube or, in the worst case scenario break, your wing. The plane is pulling
some G's at the bottom of the loop and then you add more by putting in a lot
of elevator to get a good break for the snap.



    Last year I had several incidents reported to me and my initial reaction
was to say that they were probably not flying the maneuver correctly. "You
need to slow the plane down at the bottom of the loop", I said. I must add
that what I said did not impress an FAI and pilot and District masters
champion very much. :-(



    So strapping on my asbestos underwear I decided to do some testing of my
own. At the end of November 2004 it was nice here in NJ. I took the Focus-2
and the Temptation out for a day of Masters 2005. Both planes were inspected
for tube tightness and the wing covering touched up with the glove-iron.



    Twelve flights later and an average of 10 reverse avalanches in each
flight I went home thinking all was well. (It got cold and a bit dark too).



    Back in the shop the first thing that I noticed was new wrinkles in the
covering on the Temptation wings. Nothing was loose. To test this I put the
wing-tube in the wing and leaned on it a little. All was well but I was
beginning to think that the wing must have flexed to cause the covering to
loosen up. A bit like what the covering sometimes does around the aileron
horns. It this case it was at the roots above the tubes - both sides.



    Then I turned to the Focus-2 wings. Not good! The wing-tube could now be
moved up and down and I could hear foamy crunches in both of the wings. Both
wings have Carbon tube wing tubes and it dawned on me that they could not
bend (much) or stay bent. That is why I had not seen this before. The forces
were applying themselves to the ends of the wing tubes. I opened up both
panels and added epoxy and micro balloons to stabilize the sub ribs. It was
an easy repair but could have been a lot worse if I was not looking for it.



    I am advised that stress damage is cumulative and that it does not show
up initially. It certainly had not revealed itself while I had been
demonstrating the 2005 schedule over the late summer of 2004. So where does
this leave me?  I think we have a potential problem that requires frequent
preventative equipment inspection depending upon the planes that you fly. If
you can slow down your plane and it is at around 10 lb you may never see
this happening.



    I would strongly advise checking your wing with the wing tube in place
to look for tube movement. Also look for straightness if you have an
ali-wing-tube.



    This situation is a bit unique for me. It is the first time I have been
involved with a maneuver that you don't know you are doing it wrong unless
you fly it that way too many times. And then only if the wing shows damage
or even worse it breaks in the air.



    Regards,


    Eric Henderson.



    P.S. The only time I remember seeing a reverse avalanche before is in
the hardly flown? current FAI Finals schedule.


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