Useful load

Questions and tips for safe and fun flight.

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Useful load

Postby seneca2e » Thu Mar 06, 2008 9:47 pm

What is the ACTUAL useful load on some of the owned Brantlys on here? I know the gross is 1670 and empty around 1070 book but what are some of the actual weight numbers? Does the CG move any appreciable distance as fuel is burned? What is the biggest loads you've carried and how did it handle?
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Re: Useful load

Postby SunHelo Paul » Fri Mar 07, 2008 5:41 am

The empty weight on our B2B is 1067.

Fuel burn has no effect on CG since the fuel tanks are located in the bottom of the fuselage, directly under the engine and on the CG.

I've flown it in hover at max gross takeoff weight and 15 degrees above ISA. It flew just fine with MP at about 27". This was BEFORE we corrected the grossly mis-rigged rotorhead.
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Re: Useful load

Postby N2285U » Fri Mar 07, 2008 8:08 am

My last B2B at full gross would do a max performance take-off (straight up out of my driveway 50' between trees) on a 90-degree day. There was not a bunch of extra power available, so that was definitely the limit, but it was nice to know it would do it. My first B2B struggled to the same take-off on a 50-degree day. It's all about who maintains the helicopter and how tight your engine is.
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Re: Useful load

Postby Ron Spiker » Fri Mar 07, 2008 5:07 pm

I've frequently had 400+ lbs in the seats and full fuel with no problems. There have been a few times though, on a hot day and 2500-3000' DA that with that same weight I've had to do a running take-off. We'll see now after the engine rebuild how performance changes, if any. Normally, though, if the passenger is heavier I'll wait to burn off some fuel (or start with less) before s/he gets in for their ride. Just to give me a little more wiggle room.
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Re: Useful load

Postby seneca2e » Fri Mar 07, 2008 6:39 pm

Okay so 1670-1077=593 pounds. So with a shade over a hours fuel say 15 gallons you got 503 pounds for two people. Probably gonna be out of cg in that case I would guess though.
Last edited by seneca2e on Sat Mar 08, 2008 12:09 am, edited 2 times in total.
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Re: Useful load

Postby Ron Spiker » Fri Mar 07, 2008 7:50 pm

I've never been in an out of CG situation, no matter what I had in the seats or fuel bladder. Like Paul said, the fuel is centered already, so the quantity doesn't matter.
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Re: Useful load

Postby SunHelo Paul » Fri Mar 07, 2008 9:55 pm

Actually, seneca2e is correct. In his scenario, the aircraft would be slightly forward of the CG limit. With such heavyweight pax, you need to replace some fuel weight with baggage weight to remain in CG. A better solution is to avoid so much weight in the cabin :) Two 250 pounders would find it a tight squeeze and probably couldn't raise collective anyway :)
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Re: Useful load

Postby Ron Spiker » Sat Mar 08, 2008 6:20 am

Agreed. I didn't answer completely to his post. You can get out of CG that way, and you should be doing the w/b calculation any time you are not sure whether you fall inside the limits or not. For me to get out of CG with too much weight up front I'd have to have a pax about 275+ lbs, then would have to do as you say with starting to decrease fuel and put some baggage weight in. I would just not attempt that. I know how tight it is with getting a 240 pounder in there as my pax. The w/b excel file available for download here on the site is a great and easy tool to use for this.
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Re: Useful load

Postby SunHelo Mark » Sat Mar 08, 2008 8:30 am

flylow wrote:Agreed. I didn't answer completely to his post. You can get out of CG that way, and you should be doing the w/b calculation any time you are not sure whether you fall inside the limits or not. For me to get out of CG with too much weight up front I'd have to have a pax about 275+ lbs, then would have to do as you say with starting to decrease fuel and put some baggage weight in. I would just not attempt that. I know how tight it is with getting a 240 pounder in there as my pax. The w/b excel file available for download here on the site is a great and easy tool to use for this.

I guess at a whopping 140 lbs I'll have to try my damnest then! (this is a funny posting, ya'll are supposed to laugh now) :D
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Re: Useful load

Postby seneca2e » Sat Mar 08, 2008 12:54 pm

So I don't have to look it up lol how does the empty weight/balance issues compare to a R22? Been going to go fly one to try it out but just haven't done it yet.
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Re: Useful load

Postby Ron Spiker » Sat Mar 08, 2008 1:29 pm

Here's a couple of the pages out of the R22 POH. Can't do ALL the work for you!! :D

Image

Image
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Re: Useful load

Postby seneca2e » Sat Mar 08, 2008 3:19 pm

Just looked up one that had an empty of 855 so useful load was 1370-855=515 pounds. In the one you attached I guess the empty would be 920-130(minimum pilot weight)=790 so usefule would be 1370-790=580 pounds. So it looks like the Brantly has a edge in useful load at least by the numbers.

flylow,
Any luck on getting your engine sorted out yet? We need some more Brantly videos!
Last edited by seneca2e on Mon Sep 10, 2012 8:19 pm, edited 1 time in total.
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Re: Useful load

Postby Ron Spiker » Sat Mar 08, 2008 7:32 pm

I'm taking my ship somewhere to be worked on in a couple weeks. I'll post the (good) results when he's done, as well as the (hopeful) long XC flight back home after that.

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Re: Useful load

Postby Steve Chenoweth » Sun Mar 09, 2008 9:28 am

Hopefully everyone has seen this, but for those of you who have Microsoft Excel, I created a spreadsheet with graphics for weight and balance. Click on Download on the left index, and then Weight and Balance.

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Re: Useful load

Postby seneca2e » Mon Mar 10, 2008 10:21 pm

Nice job on that Steve. Thanks for the heads up.
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