Sopwith Camel weight and balance. Scott Matthews Latrobe Valley

インデックス作成: 2026-05-22

[00:00:01][cough] [clears throat] >> Morning guys. Scott Matthews Latrobe Valley South with Camel Build.

[00:00:09]Getting very close. Here's what we did in the last few days.

[00:00:19]All right.

[00:00:20]Camel.

[00:00:23]Uh I had the weight and balance officer came down. Thank you very much. I think he's a viewer of sorts.

[00:00:32]On occasions is what I mean.

[00:00:34]Um The aircraft's fine. It's it's CG's within range. I can show you exactly on my airplane.

[00:00:42]This screw right here um happens to be on the CG.

[00:00:48]And for the model airplane guys, that's pretty much it's a 2-in spar well weather.

[00:00:55]No, it's not. Sorry. The spar the leading edge spar is here. But if it was a D box uh it'd be on the spar here.

[00:01:04]Of the lower wing.

[00:01:06]Um and how we got to that I'll try and sort of explain it, I guess. It's pretty interesting process.

[00:01:12]Relatively simple, I guess.

[00:01:15]Uh what did we do?

[00:01:17]So, if you I've written myself some notes just [snorts] so I cuz it's easy to model this up.

[00:01:26]Um >> [clears throat] >> Start off with datum. Now, datum can be anywhere. I remember working on C-130 Hercules and when we weighed I was involved in weighing a big uh four-engine Hercules the datum was in front of the aircraft.

[00:01:42]Um that allowed different radomes. You might have seen pictures with big funny radomes and things like that on on the Herc.

[00:01:49]>> [snorts] >> Um You you could put datum on the trailing edge, but then everything forward of that becomes a negative number and it gets a bit funny.

[00:01:57]Speaking of numbers, the Robert Baslee plans from Aerodrome Airplanes planes gives a an example and it's in pounds and inches.

[00:02:08]Um I found it easier to work in pounds and inches.

[00:02:14]However, my inspector um is an authorized weight and balance officer, if you like.

[00:02:23]Measured it in kilos and millimeters, so I just converted everything.

[00:02:28]Okay.

[00:02:29]So, you can establish datum.

[00:02:33]In this on this aircraft, uh I found out that well, I know the firewall and the leading edge of the top wing is on the same um plane. So, the first thing we did was get the aircraft level. Now, I did that.

[00:02:50]That actually reminds me.

[00:02:52]I'm pretty sure >> [clears throat] >> I need to get the level out of the aircraft.

[00:02:57]So, that has reminded me.

[00:02:59]If I come around here, >> [snorts] >> yeah, you can see my level over there.

[00:03:13]Maybe.

[00:03:15]Just here.

[00:03:17]So, the longeron is datum in the horizontal plane.

[00:03:23]>> [clears throat] >> I hope I don't make you guys seasick.

[00:03:28]So, I took the battery off the DeWalt drill.

[00:03:31]Uh and just sticky taped it. This has got a magnet on it, but it wasn't strong enough.

[00:03:37]So, with the uh level on the on the horizontal longeron, we raised the tail.

[00:03:45]I moved the Cruiser outside. Raised the tail to to get the bubble zero the aircraft in flight attitude, if you like.

[00:03:53]>> [clears throat] >> A quick verification of that for me, I sort of wondered around and made the prop vertical. Yeah, you could reference the vertical lines on the hangar door.

[00:04:05]And also the tail plane was still slightly, I know it's 2°.

[00:04:12]So, it wasn't level, but it was pretty close to level.

[00:04:16]So, we've got the aircraft level.

[00:04:19]>> [clears throat] >> Then we had some ramps under the wheels. Long story short, three three three scales.

[00:04:28]Move the aircraft back, put the scales in front, wheel the aircraft up some ramps onto three scales. We did that twice to give us the three weights.

[00:04:40]So, you'll end up with Well, what's the aircraft weight?

[00:04:45]Uh I can tell you somewhere I've written it down.

[00:04:49]Uh ch- ch- So, the aircraft came out at 896 lb.

[00:04:59]I'm looking up here, the projected weight empty weight, 943 lb.

[00:05:05]Um So, that's in the ballpark. That's a bit lighter than what was advertised.

[00:05:16]So, the three weights gives us you some the sum of the three weights, being the two main wheels and the tail wheel.

[00:05:23]You save that total. We'll get to that in a minute.

[00:05:27]Then [clears throat] from datum, hanging a plumb hanging a plumb bob straight down from the firewall, that was these marks on the ground, if you like.

[00:05:35]Um some of them have rubbed off.

[00:05:37]>> [clears throat] >> This mark down here being was the axle.

[00:05:43]Then for argument's sake, there was a mark here somewhere.

[00:05:53]Yeah, the aircraft's not back in the same spot, but you can see there's a mark there and a mark there.

[00:05:59]Is the was the firewall at that time.

[00:06:02]So, from that mark if there's a yellow line, if you can see that on the camera.

[00:06:10]From the firewall back to this line on the ground. So, that represented firewall back to the axle is one dimension.

[00:06:19]That gives you the um uh the moment for the weight here.

[00:06:28]We'll do the same from the firewall back to the tail wheel.

[00:06:33]That gives us three figures.

[00:06:37]So, we end up with our three weights.

[00:06:41]Gives us a total of 896 lb and our three moments which in this case, I think that was in I know it's in This is in inches. You get a figure anyway. It doesn't matter what the value is.

[00:06:57]17,000 over over 17,000.

[00:07:02]Then basically you divide the moment by the weight or the sum of all the weights.

[00:07:09]So, the sum of all the moments divided by the sum of all the weight.

[00:07:15]In a nutshell, that gives you your CG.

[00:07:18]This is not an instructional video.

[00:07:21]Um however it came down to uh the CG limits uh 20 Well, I know what they are. They're It's 20 in to 20 in to 23 in is the most rearward CG.

[00:07:41]From datum which I've used as the firewall.

[00:07:47]Obviously, if you use the prop hub, it'll be it'll be almost triple that. It might be something like 60 in.

[00:07:55]So, for me 20 in back was the So, balanced in limits, which I was surprised on the most rearward.

[00:08:10]Um so, at 23 in.

[00:08:14]But, there's no pilot and there's no fuel on board as well.

[00:08:17]So, if we add then we do the calculation add a pilot and then you can do this for different pilots um including like a helmet, parachute and a big heavy jacket or in summer in your pluggers and your t-shirt.

[00:08:33]Um but, you can sort of work out the math and I think we worked out I can have up to a 110 kilo pilot or something like that.

[00:08:42]Um which is do the quick math 220 plus pound um maybe 232 lb, something like that.

[00:08:50]So, pretty big guy.

[00:08:53]Um Where I get to? Yeah, the you add the pilot in.

[00:09:01]So, add the weight of the pilot plus the moment of the pilot to your columns and then you can add the full fuel as well and that had 10 in of moment as well. And then you get get the calculation sorted out. So, it worked out pretty easy. It probably sounds a bit confusing.

[00:09:19]Um and I did it two or three times. I've got an I've got an official document there.

[00:09:25]Um So, you can see here or maybe you can. I added the pilot um myself, 85 kilos, 187 lb ringing wet with a mo- moment arm Sorry, the distance. Yeah, the moment.

[00:09:43]The distance gives you the moment.

[00:09:47]Add the and then you just add those on.

[00:09:49]Um and as I said, the CG is I've got here Y / X.

[00:09:56]Y being the total moment divided by the total weight.

[00:10:01]Gives us your CG.

[00:10:03]That worked for me.

[00:10:06]I know I don't I open it up to whatever guys. I've paid it I paid a guy certified guy who's done the weight and balance. Don't worry about my chicken scratch there too much.

[00:10:17]And that's pretty I'm very surprised like it doesn't need lead or anything in it.

[00:10:26]Good design. Is it a fluke? Well, all these aircraft are basically identical.

[00:10:33]Um and I guess the engine mount and things like that uh has taken everything into account of the designer has.

[00:10:44]Um and the computer sort of told him where to put everything, so it actually works out.

[00:10:50]Very surprising, but she's good to go.

[00:10:56]So, I hope that all makes sense.

[00:10:57]Um Now, I must admit I'm getting a I'm working really hard on paperwork. Um a lot of work at this stage now.

[00:11:10]Not actually touching the aircraft.

[00:11:12]So, I got the aircraft registered yesterday.

[00:11:15]Registration number is 19 2291, which coincidentally reads the same both directions. 1922 91.

[00:11:25]Um And it and this is where it starts to feel like you just start throwing money to everyone.

[00:11:33]So, $90 to register the aircraft. I paid the weight and balance officer.

[00:11:38]Um now I need to get my final inspection. I'm going to pull the panels off today, pull the prop off, pull the cow off, the kidney panels, I call it, those jelly bean panels on the side or potatoes panels on the side there.

[00:11:53]Both sides.

[00:11:54]Um While I do that, I can do some extra little bits of trimming.

[00:12:00]Neaten some edges up.

[00:12:02]Get that done today.

[00:12:04]And get a final inspection, then I'll get the chief test pilot down.

[00:12:10]He can go over it as well. I do expect, you know, whatever he asked for, he'll get basically. If he's going to fly it, um I know it's in rig, so, you know, if one cable was too loose, will I have to do two. I can't just do one cable.

[00:12:26]Um but in my opinion, we're good to go. I need to do a suck and blow test, which is a um pitot-static leak test.

[00:12:37]And what else?

[00:12:40]Oh, then, which will be an enjoyable job, is to panel it all up. The panels have been on, if you've been following.

[00:12:46]Um well, the click panels haven't, but the big square ones have.

[00:12:51]Uh just some little jobs to do there. Want to vacuum out the cockpit. I need to come up with a better um I've got to keep all the all the rocks and stuff out of the cockpit.

[00:13:05]Maybe a maybe a brush as I hop in, just to brush my shoes.

[00:13:08]I know it sounds pedantic, but that that fine gravel is very abrasive and gets in everywhere.

[00:13:15]And then I probably should go over it myself to avoid a bit of embarrassment in case I've completely missed you know, everything needs to be um in safe secondary means of uh being secured like lock wire need a mirror to look at some of these split pins.

[00:13:33]Um yeah, just get everything 100% go over the aircraft.

[00:13:43]>> [sighs and gasps] >> Then there'll be more paperwork, so a final final sign-off, which goes to RAAus Australia.

[00:13:51]Another form, I guess.

[00:13:54]So throughout the build you get uh you get to see like progress progress amateur built aircraft stage inspection.

[00:14:02]So you can do the stage inspections and a final sign-off.

[00:14:06]Then I start uh chatting to RAAus via emails to you know, I might have to send a photo of the uh the warnings label warnings, which I've got in the cockpit uh contents of the tank. You need some sort of sticker, I believe.

[00:14:26]Basically copying what I did on the Cruiser.

[00:14:29]I need to write an email to RAAus Australia Recreational Aircraft Australia.

[00:14:34]So the number on the side, I've covered this before, that's just fictitious.

[00:14:38]Uh Foxtrot 2024 that's the year I predominantly built the aircraft.

[00:14:45]Um so the 19 What is it? 2291 if it was a sport aircraft like this one there's they've got to be the registration I'm talking about needs to be 150 mil high.

[00:15:01]Um and uh a big contrast, i.e. black on white.

[00:15:08]I had to apply to get this number in italics, so they lean over, and also the gray um shadow.

[00:15:19]Excepted that cuz you can't go to for instance you couldn't do uh uh this sort of font for the registration.

[00:15:31]Well, when I say you can't do it not without a prior approval.

[00:15:37]Um from RAOs and then you have to send them a photo of that.

[00:15:43]So, in that case you know, they may say to me I need a 150 mil on the side.

[00:15:50]Uh 19-2291.

[00:15:55]However, because it's a replica I think I'll get away with just a smaller one in the cockpit, but that's the next um bit of correspondence that has to go in.

[00:16:06]Well, it's all that work that I'm doing behind the scenes not actually touching the airplane.

[00:16:12]All right, guys. So, it's the latest. Just had an inspection final inspection carried out by my LAME L4.

[00:16:23]Nothing to report which is fantastic.

[00:16:27]Um maybe the elevator stick position in relation to neutral to give more up elevator. That'll come down to the test pilot's preference.

[00:16:37]Uh what else?

[00:16:41]Oh, this turnbuckle here it's got about four threads poking out, but that's a modified end on that turnbuckle. So, I've got good thread engagement.

[00:16:52]Um what else? Now, not one one thing they did pick up one thing. They being the uh LAME was the bottom exhaust stub has the weld is incomplete.

[00:17:12]Um it's just tacked on there. So, I'm going to pull off this exhaust stub and I'll get that welded.

[00:17:20]Not a big job. It's been off before, actually.

[00:17:24]Pull that off now.

[00:17:27]And one more inspection by the chief test pilot.

[00:17:33]And we should be looking pretty good.

[00:17:35]However, my least favorite part of now found my least favorite part of the whole build Good old GoPro.

[00:17:46]Yes, so my least favorite thing that I've discovered with being a home builder is the paperwork. An absolute nightmare.

[00:17:55]Um my list of jobs to do and basically nothing of that apart from the exhaust stub has got much to do with the airplane at all.

[00:18:05]Um couple little things like I got I know I've got to put a fuel you know, avgas 15 gallons or convert that to liters on the fuel tank, things like that.

[00:18:17]Paperwork, paperwork, paperwork. This is all full of paperwork. Big big tick and flick sheet today. Um all pretty much done. We have to revisit that because I think I mentioned it before, I don't want to put So, the registration's 19 2291.

[00:18:38]RAAus states 150 mil numbers on the side. So, I've emailed off to get an exemption an exemption.

[00:18:46]This being a replica aircraft, so standby on that one.

[00:18:49]Um but I'm not putting numbers on the side of my plane. So, we'll see what happens.

[00:18:56]The other little jobs calibrate the fuel tank.

[00:19:02]Um and then just paperwork. Like I said, as I'm getting older, I struggle with getting this information onto the computer. I know it sounds simple. I've got a scanner at home and somehow I lose files that are upside down.

[00:19:18]You know, struggle with that sort of stuff.

[00:19:22]Not struggle, I just get frustrated. I don't struggle. I get it done, but I find it very frustrating.

[00:19:27]Um Yeah.

[00:19:32]Um bungies.

[00:19:34]I needed to find some decent bungee cord to fix those up.

[00:19:39]So, I'm going to look at the now pull off the exhaust stub and I'll give you a quick look at that.

[00:19:44]So, you got one exhaust.

[00:19:47]You can see just where my thumb is there.

[00:19:51]The weld um is incomplete.

[00:19:59]So, we'll get that fixed up.

[00:20:05]Happens to be the one we got the wave AFR welded into it, too.

[00:20:10]All right, guys. Finished for the day.

[00:20:13]Um where did I get to?

[00:20:14]Did I tell you how much I don't like all the paperwork?

[00:20:17]And it's literally like Who wants the money?

[00:20:22]Um anyway, that's part of home building and that's what I'm trying to share with you guys, I guess what what's involved in home building.

[00:20:28]Um end result, we get a nice airplane.

[00:20:31]So, we'll continue on next video with uh Yeah, I guess the registration process.

[00:20:36]I won't bore you to tears with paperwork.

[00:20:39]Um I've got the exhaust stub on the bench here in front of me.

[00:20:43]Get that welded up.

[00:20:45]Uh and yeah, hit the computer.

[00:20:50]Lot of odd little jobs I have to do.

[00:20:53]Research an insurance company.

[00:20:55]Get the final sign-off from the test pilot.

[00:21:01]And then we'll sit around and wait, I guess. Um I do need to wait for all this stuff to come back to me to make it reggie ditch.

[00:21:07]You put in an application to test flight. This is the test pilot themselves. Um and that can take up to 10 business days.

[00:21:17]Anyway, I'll keep you informed with what we're up to as we get closer to the day.

[00:21:24]Thanks for watching. See you on the next one.