Pietenpol-List: wing strut failure
Posted: Tue Oct 17, 2006 7:57 pm
Original Posted By: "Dick Navratil"
I think I've found a reference to Pietenpol wing strut failure, to go with the recent thread on aluminum struts and jury struts and all that. Chet Peek's book, discussing Bennie Skaarberg's Model A powered Aircamper, gives Pietenpol's comments following the fatal crash: "Pietenpol and other witnesses later revealed the cause of the crash was actually the failure of the wing struts. Skaarberg had tried to do a loop, fallen out of the maneuver at the top, thus putting a reverse load on the struts, and the wing came off."Doesn't say whether Skaarberg's airplane had jury struts installed nor are there pictures of the airplane other than the mangled heap of wreckage, but apparently the comment regarding negative G's was based on this incident. The aluminum strut substitution would seem to warrant some engineering analysis not just in tension, but buckling failure modes in compression when compared with the equivalent 4130 streamlined tubing struts.Oscar ZunigaSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net________________________________________________________________________________
I think I've found a reference to Pietenpol wing strut failure, to go with the recent thread on aluminum struts and jury struts and all that. Chet Peek's book, discussing Bennie Skaarberg's Model A powered Aircamper, gives Pietenpol's comments following the fatal crash: "Pietenpol and other witnesses later revealed the cause of the crash was actually the failure of the wing struts. Skaarberg had tried to do a loop, fallen out of the maneuver at the top, thus putting a reverse load on the struts, and the wing came off."Doesn't say whether Skaarberg's airplane had jury struts installed nor are there pictures of the airplane other than the mangled heap of wreckage, but apparently the comment regarding negative G's was based on this incident. The aluminum strut substitution would seem to warrant some engineering analysis not just in tension, but buckling failure modes in compression when compared with the equivalent 4130 streamlined tubing struts.Oscar ZunigaSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net________________________________________________________________________________