Posted 28 Aug 2016 Hi everyone....especially Catalina/amphibian owners. At last my catalina (after some modifications targeting weight) has made it onto the scales and I am shearing my figures.....I also would love to know the other member's aircraft total empty weight and c of g position (please include setup setup engine/prop).My Catalina (rotax 912 with GSC 2 bladed variable pitch prop, xponder, vhf etc) has lost 20Lbs....and now is as stated below:Empty weight : 776,2 LbsAircraft c of g pos ; 22,59 inFore/aft limit used : most Fwd 11in / most Rear 17 in Also could you share what fwd/rear limits you use. Share this post Link to post Share on other sites
Posted 28 Aug 2016 Id imagine that's empty cg .the pilot passengers are quite a bit in front of the wing Share this post Link to post Share on other sites
Posted 28 Aug 2016 Dynomike, you got that right......the 22,59 in is the empty aircraft C of G Share this post Link to post Share on other sites
Posted 28 Aug 2016 The 22,59 inch c of g is measured from the datum (wing leading edge) going backwards towards the tail. It means when the aircraft sits empty on the ground it is quite tail heavy (normal for a pusher). As all the load put into the aircraft (fuel & pax) is forward of the 22,59in it will bring my Catalina once loaded within the 11-17 inch range. Hope that's clear as mud..... Share this post Link to post Share on other sites
Posted 29 Aug 2016 Copy. I forgot to factor in the config of the Catalina. Share this post Link to post Share on other sites
Posted 3 Sep 2016 Hello everybody......I am wondering if W&B is a secret thing......nobody to chime in???? What is your empty weight, C of G and configuration????Also the book says the fwd and aft limit are 11.185 and 16.5 but my Catalina was approved at 11.0 / 17.0.....any thoughts? In my manual a handwritten statement says Dean Wilson states 11.0 / 17.5 Share this post Link to post Share on other sites
Posted 3 Sep 2016 I do not have my paperwork in from of me for what the original builder has for the W&B on mine. I am still doing the rebuild and have never flown it so I don't have any updated numbers for you. I am pretty sure with the 582 it was right at the 600# empty weight.I talked to Dean about the CG on the Avid Flyers and he said I could go back to 19" with no issues, I have flown it there and its great empty. I have mine now where its at 18" and it flys much better than when I originally got it and the CG was at 11.5". With having never flown the catalina I could not tell you how it behaves with the more rearward CG, but if Dean said you could go 17.5 I would bet that is still pretty conservative. As always, pics of your plane and flying lies are always much appreciated!! Share this post Link to post Share on other sites
Posted 14 Oct 2016 I would love to look at a 600# Catalina and see how it's different from mine. Your performance must be incredible! I'm at 746#, 25.07" CG. That's 582 grey head, after significant work to bring it down from about 830#: fiberglass flaperons, fiberglass floorboard, rear seats & floorboards stripped out, no cushions, oil injection and tank removed, 2 pound LiFe3 lithium starting battery, aluminum tailwheel spring, water rudder removed, completely required with thin-gauge wiring, etc, etc. Share this post Link to post Share on other sites
Posted 14 Oct 2016 And I settled on testing a CG range of 11.185 to 16.75. My plots of stick force and stability showed that it could go a bit more rearward, but I have no need to explore that unless I start losing weight. Or get a heavier tailwheel setup. 1 person likes this Share this post Link to post Share on other sites
Posted 14 Oct 2016 Hey cowlove....great info here. I also would love to see how to get down to 600Lbs....sounds crazy low weight. I really would like to know more about your aluminum tailwheel spring as I am in the process of adapting a carbon/fibreglass spring.....Did you make the spring? What weight? Is it strong enough (should hold at least 500Lbs )? Thanks for your reply Share this post Link to post Share on other sites
Posted 14 Oct 2016 I did make the spring. I just ordered some flat bar aluminum, did some back-of-the envelope calculations to design it for about the same ultimate strength as the steel spring, tested it, and called it good. It has much less energy-absorption than the steel spring did, and of course there are big drawbacks to using aluminum in this fashion- it's almost an unsuitable material for a spring. I wouldn't recommend it. But it's just a placeholder until I can lay up a proper fiberglass spring this winter. Share this post Link to post Share on other sites
Posted 14 Oct 2016 I was in the process of laying fibers for my spring when I read a post of someone doing the same with great difficulty (hard to gauge the amount of glass to get yhe right strength & stiffness)....he found a second hand leaf spring already made from a chevrolet corvette C5 for 70 US. I just bought one for 60 US on ebay. I will have to cut the leaf spring to size. I will make a separate post for this one when I am done:) Cheers, laurent Share this post Link to post Share on other sites
Posted 14 Oct 2016 I was in the process of laying fibers for my spring when I read a post of someone doing the same with great difficulty (hard to gauge the amount of glass to get yhe right strength & stiffness)....he found a second hand leaf spring already made from a chevrolet corvette C5 for 70 US. I just bought one for 60 US on ebay. I will have to cut the leaf spring to size. I will make a separate post for this one when I am done:) Cheers, laurent Share this post Link to post Share on other sites
Posted 14 Oct 2016 (edited) Grove was making aluminum tailsprings for Kitfox at one time - I think I still have one - I planned to make a tailskid out of it. My Kitfox 3 had a 3-leaf steel spring on it - probably with the original kit. EDMO Edited 14 Oct 2016 by EDMO Share this post Link to post Share on other sites
Posted 3 Aug 2022 Hello everybody......I am wondering if W&B is a secret thing......nobody to chime in???? What is your empty weight, C of G and configuration????Also the book says the fwd and aft limit are 11.185 and 16.5 but my Catalina was approved at 11.0 / 17.0.....any thoughts? In my manual a handwritten statement says Dean Wilson states 11.0 / 17.5Avid AmphibianZK-NGURotax 582EW of 648lbs when constructedEW of 742lbs after salt water overhaul and strengthening 1 person likes this Share this post Link to post Share on other sites