skysoarer
Active Member
This evening I have spent three hours reading things on this forum. There is so much information. I am a more practical person than a maths person. I seem to be alone here in Cornwall with a fascination for flying wings, but there are loads of you here ! Having purchased Jim Marske composite design manual (Graphlite composite spars), I still cannot grasp how to join a 20 degree swept wing.Have books by Karl Nickel and Michael Wolfhardt, Sonya Englert ( SB13), Alex Stojnik, Zeke Smith, Jack Lambie and none show a method. All I can come up with is (in theory) laying up a spar which is curved (40degrees) within the confines of the 'fuselage' and wing roots, and having the join further out where the spar is straight. After reading about wing twist, the spar could have less sweep than the wings but with an aspect ratio of 1:4.93, perhaps may not be required. Am building a model using the MH70 section, though open to suggestions.The idea is for a swept, constant chord wing ( good lift distribution) with winglets as these hopefully reduce induced drag and improve adverse yaw, and using elevons. We have a category in the UK called SSDR ( single seat deregulation) with a total empty weight of 115KG and wing loading less than 10 KG/sq.m. My wing has 20 degree sweep, wingspan of 3.7m and chord of 1.5m. Winglets are as per Karl Nickel and Michael Wolfhardts ideas. Like the idea of the six flap function as proven on RC aircraft, but how to construct a linkage system for a man carrying plane? Have ordered a set of plans for the Vampyr / Pelican which should arrive any day, as interested in how it is built, but in the Nickel-Wolfhardt book, they advise lengthening the chord in the elevator section for the Fauvel AV36, which I think the Vampyr/Pelican is based on. This apparently would smooth out the lift distribution and "thus reduce the induced drag". The reason being that pilots of the AV36 reported hopping, and with elevator down, this is wash in, not good but bad lift distribution and stall behaviour are confined by the two fins. I have not found any literature describing the flight characteristics of the Pelican to know if this also may be affected in the same way, but tend to think it could be. I would like to build the Vampyr, but obviously make use of new knowledge to aid its flying characteristics. Did think about sweeping the wing at the join and using elevons and winglets, as did someone else here, BUT, it did fly as per the plan so best leave 'as is', apart from the chord extension on the elevator ! Apologies for drifting off the title. Look forward to your comments. Regards Bruce
Last edited:
