Weight & Balance Problems

Important: These forums are for discussions between SkyDemon users. They are not routinely monitored by SkyDemon staff so any urgent issues should be sent directly to our Customer Support.

Weight & Balance Problems

Author	Message
dave_kent	dave_kent posted 7/28/2013 3:00:04 PM Topic Details Share Topic
Group: Forum Members Posts: 37, Visits: 2K	Hi, I'm trying to enter the weight and balance schedule into SD (windows) but I think I've got some problems with the units relative to each other. Hopefully the attached scans of the schedule are readable and someone can tell me what I need to put in the fields (I think it's something to do with the CoG setting!). Thanks in advance Dave
	Reply Like 99
Richardd55	Richardd55 posted 7/28/2013 5:30:19 PM ANSWER Post Details Share Post
Group: Forum Members Posts: 16, Visits: 1.8K	Hi Interesting. I am only used to working with Weight/Lever Arm Envelopes. You have a MOMENT envelope. I can't be sure if the MOMENT points from that envelope should be used in SkyDemon (SD). I need to get my head round that. Might be ok? SD recommend you do the conversion I can't see a CoG value for your aircraft. That should be in the POH. It might be 1.003m (100.3cm). Need to check that. I don't know that it matters that you have gone anticlockwise round the envelope. I put mine in clockwise. (so your 2nd point would be 790,890). SD recommend clockwise. Personally I would find all the lever arm/weight coordinates for the Normal category (assuming that's the category you'll mainly want to fly within). They are usually in the POH and probably the ones you should use but you can get good approx figures from your envelope image knowing that Weight x LeverArm (dist) = Moment so Lever Arm = Moment/Weight Your first envelope point is approx. 620,700 Convert the 620 Moment to Lever Arm. ie 620/700 =0.8857 m or 88.57 cm (if you prefer cm) so first envelope point is 88.57,700 Similarly 2nd envelope point 790,890 becomes 88.76,890 Good Luck .... and do check my maths!!!!! Richard Edited 7/28/2013 5:58:02 PM by Richardd55
	Reply Like 100
dave_kent	dave_kent posted 7/29/2013 6:48:33 PM Post Details Share Post
Group: Forum Members Posts: 37, Visits: 2K	Thanks Richard - it was the starting CoG that was throwing me. I've put in 100.3 for now and it makes everything look better, and I'll check the actual figure when I get to the airport at the weekend. Dave
	Reply Like 101
filippo1974	filippo1974 posted 10/15/2013 9:59:06 AM Post Details Share Post
Group: Forum Members Posts: 12, Visits: 38	Hi, I resumed this thread just to notify that I found some abnormal behaviour of SkyDemon plan (for PC) when configuring the weight & balance limits for an aeroplane. When the regional settings of Windows are configured so that the decimal separation character is the COMMA ',' and the list separation character is SEMICOLON ';', then SkyDemon on a random basis does not read and use all the points of the w&b limits polygon I defined, and/or does not consider subsequent modifications made to the polygon definition. Unfortunately, the aforementioned regional settings are by default for an italian setup of Windows. If I manually modify these settings to have '.' as decimal separator and ',' as list items separator, then everything works just fine. SkyDemon Plan 2.7.2, Windows 7 Ultimate x64, all patches & updates by MS in place (including those for the .NET framework). Best regards, Filippo ============================================== Filippo1974 PPL(A) holder - CPL + IR + MEP in progress Senior specialist in throwing Italian ATS units into panic every weekend.
	Reply Like 56