W&B

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Finley
Posts: 31
Joined: Sun Dec 18, 2016 7:54 pm

W&B

Post by Finley »

What are you guys using for a CG range? My numbers as it sit are 1947Lbs. 98.32". I use the tip of the spinner as a reference point.

I found in some of the original builders notes that the range was 11". But nothing about where the range started and stopped. ie: 90" - 101"

I've also seen that the CT has a very small CG range. Does anyone know if 11" would be correct?
LouisCarre
Posts: 21
Joined: Sun Oct 16, 2016 10:19 am

Re: W&B

Post by LouisCarre »

Hi,

Auriga Express 2000 RG, I have empty weight of 2074 # at 46.4 inch, Datum is firewall.

I'm using cg range from 43 to 55 inch from Datum

Regards,

Louis
Express 2000RG
C-GGVX
Rimouski, Quebec, Canada
282ex
Posts: 54
Joined: Wed Aug 10, 2016 12:59 am

Re: W&B

Post by 282ex »

i'm hanging on to this post link for reference. Did you still need w&b help? I have a contact, he used to work for Glasair and Express and is open to providing advice.
Erik Petersen
Wheeler Express Series 90 Auriga
Sequim, Wa
Finley
Posts: 31
Joined: Sun Dec 18, 2016 7:54 pm

Re: W&B

Post by Finley »

It would be great to talk to your guy about the W&B for my plane. I have had several conversations about the issue, but no one who knows Express CT's.

Thanks for your help!
Guapo
Posts: 8
Joined: Thu Jan 11, 2018 8:26 pm

Re: W&B

Post by Guapo »

Good evening!
I have a CT and I have all the manuals, including I did my Weight and Balance
If you need contact me
5567999652503
juniorguapocar@gmail.com
Guapo Jr
Tres Lagoas, Brazil
PT-ZUX Express CT Builder
Finley
Posts: 31
Joined: Sun Dec 18, 2016 7:54 pm

Re: W&B

Post by Finley »

Guapo-

It would be great to chat with you about your plane. I haven't flown a Wheeler, so any info you could pass on would help.

I will try to call you on Sat. the 2nd.

Thanks

Finley
270-839-7668
jchisolm
Posts: 103
Joined: Tue Jun 17, 2014 9:56 pm

Re: W&B

Post by jchisolm »

I've been busy with job related things and have not had much time to look at the messages here.

In the CAFE article on N360EZ the table has the datum 34" forward of the firewall which would be FS 0 (zero, The firewall is installed at FS 34) and CG limits of 76.25" to 82".

The example express POH has a range of FS 74 to 84.95 (datum at 34in forward of the firewall as above)

In an Express Builders Exchange news letter for C-CUPZ (datum listed as the fuselage/cowl joint which would be close to FS34) says:

CG limits supplied by Wheeler - Leading edge of MAC is at 33.25in, Length of MAC 51.33.
The CG limits are stated as FWD: 19% of MAC = 43in (51.33*.19 = 9.75 + 33.25 = 43)
AFT CG 40% of MAC = 53.78"

Adjusting these numbers by +34 (to get us to datum zero) gives 77" to 87.78

In a NOR CAL Express Builders news letter Vol 1 number 6, there is data for N300EX. Reference datum 33.5" forward of the FORWARD face of the firewall. This would effectively be FS 0.
Leading edge of MAC is at FS 67. MAC is 51.3 inches in length. CG range is listed as FWD 74.7 (15% of MAC) and AFT 87.5 (40% of MAC)
These number match up closely with C-CUPZ given the uncertainty of exactly where the datum was on C-CUPZ.

In my build manual, procedure for inspection holes, it says the spar center line is at FS 88.85

An example spread sheet I found for N190AM has:

Maximum weight 3200 lbs
Most forward arm 74.69 ins
Most rearward arm 84.95 ins

The 84.95" max AFT listed in the example POH, for N190AM and N49EX is at 38.8% of MAC.

Here are the arms used in the spread sheets for N49EX and N190AM:
pilot/passenger 76.8
rear passengers 123.1
fuel, inbd 80.2
fuel, outbd 80.2
luggage 150

The CAFE article for N360EZ uses arms of:
Pilot 76.9
Passenger, rear 122.0
Fuel, wing tank 80.1
Baggage 132.2
Joe Chisolm
Express CT builder
Marble Falls, Texas
Finley
Posts: 31
Joined: Sun Dec 18, 2016 7:54 pm

Re: W&B

Post by Finley »

First I'd like to thank Mr. Guapo Jr and Mr Chisolm. They both have taken time to help.

Junior' Express CT #'s look very close to my numbers. I won't post them here, because he shared them with me and I haven't
asked permission.

N185WE IO-540 C4B5
Using FS-0 at the tip of my spinner. (The original builder has his CG calculated from there.) He is unavailable.

Front Wheel is 40 @ 472 18880
Mains are 117 @1475 172575
Front PX 99
Rear PX 152
98.33 1947 191445

Just in front of my forward MAC. which I have marked on my wing, at the hanger.
I don't have my MAC numbers with me.

While calculating the CG using the firewall as FS-34. My CG falls within .5 of my numbers from the spinner.
The reason I'm beating this horse is all the different info I've seen, along with all the discussion on CG importance with the CT.
The Original builder left so much data out of his calculations. However his final total weight (1935) and empty CG (98.56) seem to be inline with what I'm getting.

Joe-
What flying qualities are you getting with forward, then Aft CG?

Thanks again with your help.
I will be back with more info from my plane.
Finley
Posts: 31
Joined: Sun Dec 18, 2016 7:54 pm

Re: W&B

Post by Finley »

Louis and Erik-

Thanks for your help as well.
I did compare Louis' # to mine and will share those as soon as I retrieve them from the hanger.

Blue Skies!
LouisCarre
Posts: 21
Joined: Sun Oct 16, 2016 10:19 am

Re: W&B

Post by LouisCarre »

Good,

Actually I have fowler flaps instead of reflex flaps, and it flies nose down a little bit...

If more strait, i figure out that speed would be a little faster...

Regards,

Louis
Express 2000RG
C-GGVX
Rimouski, Quebec, Canada
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