A aviation & planes forum. AviationBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » AviationBanter forum » rec.aviation newsgroups » Soaring
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Max Weight of Non Lift Producing Components



 
 
Thread Tools Display Modes
Prev Previous Post   Next Post Next
  #7  
Old December 1st 17, 09:14 AM posted to rec.aviation.soaring
Jim White[_3_]
external usenet poster
 
Posts: 286
Default Max Weight of Non Lift Producing Components

At 22:44 30 November 2017, Bob Kuykendall wrote:
On Thursday, November 30, 2017 at 9:00:07 AM UTC-8, Kevin Neave wrote:

So what does the main pin(s) count as?


Very incisive question! That's a good demonstration of how the mass of
non-=
lifting is a reasonable metric for the approximation of wing main spar
maxi=
mum bending moment, but is still just an approximation.

At issue is that using a maximum mass of non-lifting parts to limit the
win=
g spar bending moment is only valid when any mass added to the wings is
dis=
tributed spanwise according to the wing lift distribution. So if for
whatev=
er reason you add a bunch of mass to the inboard ends of the wings
(deplete=
d uranium root ribs maybe?), you can be within the allowable non-lifting
ma=
ss and within the load factor envelope, but still develop excessive wing
sp=
ar bending moment.

Bottom line: Respect mass limits to the spirit and the letter of the
publis=
hed values. And if you want a glider with lots of non-lifting mass

margin,
=
build an HP-24. The one we finished last summer has an empty non-lifting
ma=
ss of ~220 lbs (ready to fly with batteries, instruments, 24 ft^2 O2
bottle=
, etc) and a maximum of ~605 lbs, yielding a payload of ~385 lbs for
pilot,=
parachute, FES, electric self-launch, BRS, etc.

--Bob K.

Ever wondered why commercial jets now all hang the engines from the wings?
Lighter spars and the added roll inertia in the wing component reduces the
effect of turbulence on the passengers.

 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Fiberglass cloth weight vs 'finished' weight Fred the Red Shirt Home Built 12 April 5th 08 04:24 PM
Glider Weight/Wing Loading and determing speed for best L/D for a given weight 65E Soaring 3 January 26th 06 09:26 PM
How much weight will 15 ft.³ of helium lift? John Doe Home Built 1 December 3rd 04 04:07 PM
Crosswind components James L. Freeman Piloting 25 February 29th 04 01:21 AM
Empty/Gross weight Vs. Max. Pilot weight Flyhighdave Soaring 13 January 14th 04 04:20 AM


All times are GMT +1. The time now is 09:01 PM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004-2025 AviationBanter.
The comments are property of their posters.