Brodhead Pietenpol Association

Original Posted By: Christian Bobka
Date: Dec 31, 2000

Original Posted By: "Christian Bobka"
the only reason I'm adding a tad of dihedral is to kill the "drooping wing"visual effect of a straight winged Piet.DJ VeghN74DVwww.raptoronline.comMesa, AZ----- Original Message -----

Original Posted By: clif
Chris Bobka,Further to your treatise on dihedral, this is what an old aeronauticalengineeringbook of mine says:"...the High Wing or Parasol type of monoplane, which often has no DihedralAngle. The Low Wing Monoplane, on the other hand, must usually have aDihedral Angle." Ref. MECHANICS OF FLIGHT by A. C. Kermode London Sir Isaac Pitman & Sons, Ltd. 1942Kermode essentially says what you are saying: a parasol monoplane such asthe Pietenpol needs no dihedral for adequate lateral stability. (In spite ofthisI did incorporate a modicum of dihedral in my Pietenpol, mainly to reducethe "droopy" look while parked.)The other day I obtained a brochure on the new Murphy JDM 8 which in-cluded a basic 3-view layout showing zero dihedral! Since this airplane hasa low wing, it seems strange that they went this route. It strongly remindsmeof the Druine Turbulent (a delightful little plane) I test flew for a friendyearsago, but the Turbulent had dihedral typical of low wing monoplanes. I knowof several low wingers with no dihedral, but some were not all that success-ful.Back in the 1980's a fellow from British Columbia built a low wing Pietenpolpowered by a Continental A-65. It had strut braced wings with appropriatedihedral for this configuration. It flew successfully, but had a high sinkrate.He cited easy access to the cockpits and good visibility as the chiefbenefits.Graham Hansen (Pietenpol CF-AUN) in sunny Alberta, Canada.________________________________________________________________________________Date: Thu, 06 Feb 2003 00:15:15 -0800

Original Posted By:> Christian Bobka