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Re: [CriCri] Re: flutter problems

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  • W. David Doiron
    In , on 07/28/03 ... Actually there have been 2 that I know of, both in Europe, and both due to obvious pilot error...NEVER an
    Message 1 of 9 , Aug 2, 2003
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      In <bg3oit+vbtm@...>, on 07/28/03
      at 06:04 PM, "Stephan" <sboutenko@...> said:

      >I wanted to thank you all for very useful information. I think I
      >finally get the picture. See, initially I thought that the plane was
      >called Cricket by the FAA just so that it has a name in the US, but now
      >I understand that the Cricket is actually the poorly modified version
      >built (as a kit) by Zenair and is not the same as the original CriCri,
      >which has never had a fatal accident (?)

      Actually there have been 2 that I know of, both in Europe, and both due
      to obvious pilot error...NEVER an airframe failure.


      >I also know that the plans I
      >have are of the original Cricri and not the other one, so I feel much
      >better. Thanks again for the help of all who responded to my original
      >email. It's good to know that there are many enthusiasts out there who
      >share the same passion for this beautiful airplane like I do.
      >Stephan.


      Bon chance...David
      ----------------------------------------------------------------
      W. David DOIRON <DDoiron"at"cox.net>
      ----------------------------------------------------------------
    • W. David Doiron
      In , on 07/26/03 ... Sorry, but the KNOWN cases of Zenair kit aileron flutter were: Morris, DeJarnette,
      Message 2 of 9 , Aug 2, 2003
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        In <20030726173818.21003.qmail@...>, on 07/26/03
        at 06:38 PM, John Lamphere <k_john_lamphere@...> said:

        >The only flutter issues that I have heard of were
        >found in the flaperons on one example of the aircraft.

        Sorry, but the KNOWN cases of Zenair kit aileron flutter were: Morris,
        DeJarnette, Tiffany, Harper, and one other I forget the name of. And of
        course Jim Harper had 2...


        > Post flight inspection of the controls found
        >excessive play in the linkages.

        Again sorry, but NOT true. This "excessive play" quote came
        out of the mouth of Chris Heintz in an effort to deflect attention away
        from himself and his killer kit. (apparently the EAA did fall for this
        ruse...)
        Chris has NEVER inspected Jim Harper's wreckage, but I HAVE, and it is as
        obvious as the nose on your face that flutter originated with the
        Zenair-modified steel tuning-fork tube.


        >From what I heard, the controls were adjusted and subsequent flights
        >proved normal.

        Urban myth.


        >Also, in reference to the last reply,
        >the fatal accident that I know of to my knowledge was
        >not put down to flutter specifically.

        The NTSB and FAA accident reports both show the cause as aileron flutter.


        >In the fatal incident that I am refering to the control linkage on
        >the horizontal tail failed, and the pilot lost pitch control.

        Jim crashed because the link (also a Zenair-modified part..)
        on the tail failed. But the link on the tail failed because of the
        extreme aileron flutter.


        >I have also heard that the tailplane may
        >have separated completely from the aircraft.

        No, it did not.


        >I do not, and I am not sure if anyone knows of the failure
        >mode for this incident, that is whether it occurred
        >under high load or normal flight conditions.

        Level flight on downwind at about 80 mph.


        >It certainly ruined the pilots day and appears to be the
        >main incident leading up to Mr. Colomban's departure
        >from the North American Market for his aircraft
        >design.

        That is correct.


        >I am in the process of building a Zenair kit Cricket.
        >I have looked at the Zenair mod's for the horizontal
        >tail plane mount, and compared them to the drawings
        >supplied with the kit. The drawings are that of the
        >original design by Mr. Colomban. After reviewing
        >everything, I believe like most others on this site
        >that the Zenair Tail mod is a bad one, cheapening and
        >possibly

        Not possibly, most definitely.


        >rendering the aircraft less safe. When I
        >aquired my project, much of the work in this area had
        >already been completed by the former owner in
        >compliance with the Zenair mod. I didn't like it, and
        >have taken great pains to return to the original print
        >specs. This rework cost me in the neighborhood of 30
        >hours put I am far happier with what I have, and will
        >feel much more comfortable flying with the "new" tail
        >knowing what's back there is built right.

        You have done the right thing; most of all, be sure to
        discard the steel Zenair tuning-fork in the aileron linkage.


        >I think that this airplane is a good design, and
        >although unconventional, should be as safe as any
        >aircraft if built correctly and with care. Just my
        >opinion.....
        >John

        John I am not trying to pick on you, and you seem to have
        a good natural instinct concerning the design.
        But since I knew Jim Harper personally, and knew he was
        a meticulous craftsman, I felt it important to tell the truth that he did
        NOT leave any play in the linkages.
        To make sure, I spent several days inspecting the wreckage
        in Colorado. If you want the details of my findings, give me a call:
        480-967-2309.
        I would not believe anything Chris Heintz said.
        He lied to Michel Colomban, and he lied to me.
        Jim made one BIG mistake: that was to take Chris Heintz
        advice on making flight controls...

        ----------------------------------------------------------------
        W. David DOIRON <DDoiron"at"cox.net>
        ----------------------------------------------------------------
      • John Lamphere
        David, Thank you for some clarity on these issues. I was simply trying to join in this discussion as the statements I made were based only on the limited
        Message 3 of 9 , Aug 5, 2003
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          David,

          Thank you for some clarity on these issues. I was
          simply trying to join in this discussion as the
          statements I made were based only on the limited
          knowledge that I had to work from.

          > The only flutter issues that I have heard of were
          >found in the flaperons on one example of the
          > aircraft.

          I certainly was not suggesting poor construction on
          Jim's part!

          Also, I did not know of the "Zenair mod steel tuning
          fork" in the aileron linkage on the kit cricket. My
          project is nothing like the kit, having been
          extensively changed back in favor of the orriginal
          design. Also many of the kit supplied parts that came
          with it have been lost and I do not have them. I do
          however have the proposed Zenair mods, and after
          looking at them I have to agree, they are crap.

          If I offended anyone by putting my two cents forward I
          apologise. This forum is however for discussion of
          the Cri Cri design, and If you have imparted some
          knowledge upon me that may save my life, I call that
          success. Thank you.

          Incidently, I had the opportunity to fly a CH2000 back
          in July of 2000 (a Chris Hientz certified airplane
          design) and not that others don't but, I didn't like
          it much either.

          John

          --- "W. David Doiron" <DDoiron@...> wrote: > In
          >
          <20030726173818.21003.qmail@...>,
          > on 07/26/03
          > at 06:38 PM, John Lamphere
          > <k_john_lamphere@...> said:
          >
          > >The only flutter issues that I have heard of were
          > >found in the flaperons on one example of the
          > aircraft.
          >
          > Sorry, but the KNOWN cases of Zenair kit aileron
          > flutter were: Morris,
          > DeJarnette, Tiffany, Harper, and one other I forget
          > the name of. And of
          > course Jim Harper had 2...
          >
          >
          > > Post flight inspection of the controls found
          > >excessive play in the linkages.
          >
          > Again sorry, but NOT true. This "excessive play"
          > quote came
          > out of the mouth of Chris Heintz in an effort to
          > deflect attention away
          > from himself and his killer kit. (apparently the EAA
          > did fall for this
          > ruse...)
          > Chris has NEVER inspected Jim Harper's wreckage, but
          > I HAVE, and it is as
          > obvious as the nose on your face that flutter
          > originated with the
          > Zenair-modified steel tuning-fork tube.
          >
          >
          > >From what I heard, the controls were adjusted and
          > subsequent flights
          > >proved normal.
          >
          > Urban myth.
          >
          >
          > >Also, in reference to the last reply,
          > >the fatal accident that I know of to my knowledge
          > was
          > >not put down to flutter specifically.
          >
          > The NTSB and FAA accident reports both show the
          > cause as aileron flutter.
          >
          >
          > >In the fatal incident that I am refering to the
          > control linkage on
          > >the horizontal tail failed, and the pilot lost
          > pitch control.
          >
          > Jim crashed because the link (also a Zenair-modified
          > part..)
          > on the tail failed. But the link on the tail failed
          > because of the
          > extreme aileron flutter.
          >
          >
          > >I have also heard that the tailplane may
          > >have separated completely from the aircraft.
          >
          > No, it did not.
          >
          >
          > >I do not, and I am not sure if anyone knows of the
          > failure
          > >mode for this incident, that is whether it occurred
          > >under high load or normal flight conditions.
          >
          > Level flight on downwind at about 80 mph.
          >
          >
          > >It certainly ruined the pilots day and appears to
          > be the
          > >main incident leading up to Mr. Colomban's
          > departure
          > >from the North American Market for his aircraft
          > >design.
          >
          > That is correct.
          >
          >
          > >I am in the process of building a Zenair kit
          > Cricket.
          > >I have looked at the Zenair mod's for the
          > horizontal
          > >tail plane mount, and compared them to the drawings
          > >supplied with the kit. The drawings are that of
          > the
          > >original design by Mr. Colomban. After reviewing
          > >everything, I believe like most others on this site
          > >that the Zenair Tail mod is a bad one, cheapening
          > and
          > >possibly
          >
          > Not possibly, most definitely.
          >
          >
          > >rendering the aircraft less safe. When I
          > >aquired my project, much of the work in this area
          > had
          > >already been completed by the former owner in
          > >compliance with the Zenair mod. I didn't like it,
          > and
          > >have taken great pains to return to the original
          > print
          > >specs. This rework cost me in the neighborhood of
          > 30
          > >hours put I am far happier with what I have, and
          > will
          > >feel much more comfortable flying with the "new"
          > tail
          > >knowing what's back there is built right.
          >
          > You have done the right thing; most of all, be sure
          > to
          > discard the steel Zenair tuning-fork in the aileron
          > linkage.
          >
          >
          > >I think that this airplane is a good design, and
          > >although unconventional, should be as safe as any
          > >aircraft if built correctly and with care. Just my
          > >opinion.....
          > >John
          >
          > John I am not trying to pick on you, and you seem to
          > have
          > a good natural instinct concerning the design.
          > But since I knew Jim Harper personally, and knew he
          > was
          > a meticulous craftsman, I felt it important to tell
          > the truth that he did
          > NOT leave any play in the linkages.
          > To make sure, I spent several days inspecting the
          > wreckage
          > in Colorado. If you want the details of my findings,
          > give me a call:
          > 480-967-2309.
          > I would not believe anything Chris Heintz said.
          > He lied to Michel Colomban, and he lied to me.
          > Jim made one BIG mistake: that was to take Chris
          > Heintz
          > advice on making flight controls...
          >
          >
          ----------------------------------------------------------------
          > W. David DOIRON <DDoiron"at"cox.net>
          >
          ----------------------------------------------------------------
          >
          >
          >

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