Help with Weight and Balance envelope C172

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Help with Weight and Balance envelope C172

Help with Weight and Balance envelope C172

Author	Message
Liam Sandie	Liam Sandie posted 5/23/2013 3:04:01 PM Post Details Share Post
Group: Forum Members Posts: 72, Visits: 261	Sorry for mis understanding but ignore the graph? The issue I think is sd sets their graphs up different to most poh https://www.instagram.com/liam548/
	Like 93
*stevelup*	*stevelup* posted 5/23/2013 3:00:40 PM Post Details Share Post
Group: Moderators Posts: 593, Visits: 4.9K	The moment graph will lean to the right, the CG graph would usually have a straight right hand edge.. Personally, I'd ignore the graph in your POH and just use the textual information.
	Like 102
Liam Sandie	Liam Sandie posted 5/23/2013 10:44:36 AM Post Details Share Post
Group: Forum Members Posts: 72, Visits: 261	Steve what does your point mean regarding the last figure? https://www.instagram.com/liam548/
	Like 98
Lyndon	Lyndon posted 5/23/2013 10:24:29 AM Post Details Share Post
Group: Forum Members Posts: 1, Visits: 3	Think I've worked out the figures to input into SD, but the graph (arm length vs weight) comes out a little differently shaped to the one on the spreadsheet (moment vs weight). instead of moment x 1000 weight of the POH 50.7 1500 67 1950 87.5 2450 107.3 2450 84.3 1500 I get this arm weight in sky demon 33.8 1500 34.36 1950 35.71 2450 43.8 2450 56.2 1500 I've tried a few plane configurations of various weights in different locations on both the spreadsheet and SD and they do appear to be working the same so I guess its right, its just a little disconcerting they look so different. Can anyone check this for me please? -Lyndon
	Like 106
Liam Sandie	Liam Sandie posted 5/23/2013 8:33:51 AM Post Details Share Post
Group: Forum Members Posts: 72, Visits: 261	Thank you Steve. Is the link the link to the file for sd? https://www.instagram.com/liam548/
	Like 106
*stevelup*	*stevelup* posted 5/23/2013 8:22:21 AM Post Details Share Post
Group: Moderators Posts: 593, Visits: 4.9K	Link
	Like 101
*stevelup*	*stevelup* posted 5/23/2013 8:18:53 AM Post Details Share Post
Group: Moderators Posts: 593, Visits: 4.9K	The reason you are struggling is because the graph in your spreadsheet shows the moment, not the CG. I've tried converting the moment back (by dividing the moment by the weight), but it still doesn't make sense - I have no idea where the last figure came from... I'd suggest carefully checking this against the POH instead. Disregarding the last figure, the graph comes out OK and looks sane when compared with the numbers in a random POH I found on the internet, but you must do it properly using your figures.
	Like 100
Liam Sandie	Liam Sandie posted 5/22/2013 10:33:15 PM HOT Topic Details Share Topic
Group: Forum Members Posts: 72, Visits: 261	Hi all, just subscribed to SD now Android is supported (hope the full range of features make it across). Anyway I am having real difficulty setting up the w&b envelope for our aircraft. There is already an online envelope which uses a Microsoft spreadsheet. This can be found here:- http://www.dukeriesaviation.f9.co.uk/downloads/wb/G-ROLY_WeightBalance.xls Can someone please assist me with using this graph to set up my Skydemon as I cannot get it to appear correct at all. Many thanks Liam https://www.instagram.com/liam548/
	Like 114