Because when, in flight, all the weight is concentrated in the fuselage and the lift is distributed along the full span of the wing, the maximum amount of shear is applied to the wing attach fittings. When the weight is distributed along the span of the wing, it results in less shear at the wing/fuselage juncture.
For further reading look up zero fuel weight. Sent from my iPad > On Dec 14, 2020, at 6:45 PM, Mark Wegmet via KRnet <krnet@list.krnet.org> > wrote: > > Okay, maybe I'm not too bright... I need to understand how you get reduced > load on the wafs with fuel in the outer wing. Assuming 6 pounds per gallon, > how does (for example) a 10 gallon wing tank reduce stress on the waf if > (lift issues aside) you maneuver in any direction, considering inertia and > mass, that the 60 pounds in each outer wing doesn't affect the load on the > wafs? > > If the fuel is in the wing stubs and/or a header tank, I could see how the > 'load' on the wafs might be neutral (all things considered), but with moment > arm considerations, wouldn't hanging that 60 pounds or so out at the outer > wing increase the flex load at the waf? > > Just asking for a friend. The CG issue would (I would think) depend on > placement of the tanks - wing or tip - relative to the "normal" CG > calculations for the airframe. > > Blue skies, calm winds. > > Mark W > N952MW (res) still workin on it. > > -----Original Message----- > From: KRnet [mailto:krnet-boun...@list.krnet.org] On Behalf Of Mike > Stirewalt via KRnet > Sent: Monday, December 14, 2020 5:34 PM > To: krnet@list.krnet.org > Cc: laser...@juno.com > Subject: KR> Wing tanks > > Larry said, > >> "Fuel in the outer wings also reduce the weight carried by the > W.A.F.'s." > > That is so true. Tip tanks, or outer wing tanks, carry with them great > advantages. Not only do they carry weight without affecting CG to any > significant extent, but unloads stress at the wing root, making for a > more resiliant structure. A third virtue, at least with tip tanks, is > their reduction of tip vortice drag, acting as winglets. > > Mike > KSEE > > ____________________________________________________________ > Sponsored by > https://www.newser.com/?utm_source=part&utm_medium=uol&utm_campaign=rss_tagl > ines_more > > Trump Says Barr Has Resigned > http://thirdpartyoffers.juno.com/TGL3141/5fd7f6ddb5cea76dd2087st02vuc1 > Biden Wins Electoral Vote, With No Defections > http://thirdpartyoffers.juno.com/TGL3141/5fd7f6ddd997176dd2087st02vuc2 > New COVID Variant Is 'Something to Keep an Eye On' > http://thirdpartyoffers.juno.com/TGL3141/5fd7f6de92f976dd2087st02vuc3 > > _______________________________________________ > Search the KRnet Archives at > https://www.mail-archive.com/krnet@list.krnet.org/. > Please see LIST RULES and KRnet info at http://www.krnet.org/info.html. > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change > options. > To UNsubscribe from KRnet, send a message to krnet-le...@list.krnet.org > > > _______________________________________________ > Search the KRnet Archives at > https://www.mail-archive.com/krnet@list.krnet.org/. > Please see LIST RULES and KRnet info at http://www.krnet.org/info.html. > see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change > options. > To UNsubscribe from KRnet, send a message to krnet-le...@list.krnet.org _______________________________________________ Search the KRnet Archives at https://www.mail-archive.com/krnet@list.krnet.org/. Please see LIST RULES and KRnet info at http://www.krnet.org/info.html. see http://list.krnet.org/mailman/listinfo/krnet_list.krnet.org to change options. To UNsubscribe from KRnet, send a message to krnet-le...@list.krnet.org
