What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Weight and balance numbers

RV7 IO360 Sam James Plenum Injected leather seats no side panels
painted tilt up oil no fuel IFR 1093 lbs
 
RV7
Tip Up
No Paint
SJ Cowl
IO360 M1B
CS Composite Hartzell
1/2 Raven
Oil Accumulator
OA Seats, Abby Leather w/heat
Classic aero - carpets side panels
Fire extinguisher

1139 lbs
MainR 538
MainL 535
TW 66

She is a little heavy, but I am not. :D
 
RV-7 Slider
Lycoming IO-360-M1B
MT Constant Speed Prop
AFS 5600 Quick Panel with Dual ADAHRS
Manual Flaps and Trim
Full Classic Aero interior with heated seats
Rocket link tailwheel steering arm
Oversized 380x150 Tires
Exterior a mix of paint and vinyl

Left Main 500.8
Right Main 507.5
Tailwheel 72.8
Empty Weight 1081.1
Useful Load 718.9
CG 80.62


This is a great thread for anybody in the building/planning stage of a 7. If you are building a taildragger, I would recommend keeping everything mounted as far forward as possible especially if you are going with a light prop. It seems the 7 was designed around a heavier engine and heavier prop. Once you start adding people and baggage, the CG can move aft quickly, especially if you have a composite prop, even if it is a Constant Speed. Without the weight on the nose you can end up with a limited baggage capacity if you don't plan accordingly.
 
RV-7 weight numbers

I completed the weight and balance on my RV-7 today with the following configuration and results:

Type: RV-7
Engine: IO-360M1B with dual PMAGS
Prop:Hartzell 72" Blended Airfoil CS prop
Dual Andair wing root gascolators, Andair fuel pump, Andair fuel valve.
Single G3X Touch IFR panel (GTN 625, G5, heated pitot, autopilot etc...)
Electric pitch and roll trim
Night lighting (flyleds Nav/Strobe and Baja Squadron Pro landing lights)
Tosten military grips
Dual brakes
Airframe fully primed internally (Ekopoxy) and fuselage fay sealed.
Canopy Supertracks (best mod on the aircraft)
Sikaflex Canopy and Carbon/Glass skirt
Full carpet (walls self adhesive "fossliner" 340gsm, baggage and seat pan with 490gsm Spectropile and forward floor with Autex Reef 800gsm)
Forward floor 3/4" sound insulation foam.
All Van's seat cushions/spacers installed (canvas covered)
5 point Crow harnesses.
EarthX lithium battery, single alternator
Oversized 380-150x5 tires (second favourite mod)
JD Air Parts Tailwheel assembly and vent/drain fairings.
Ceramic wool/stainless firewall protection
Titanium/ceramic wool belly fire protection
Fire extinguisher
Flight manual
Luggage net
Full external paint and all fairings in place.
Full oil
Unusable fuel (22lb or 3.68gal total)

Total Empty Weight: 1135lbs
Empty Arm: 79.35"

Tailwheel weight: 62lbs

So it appears I built a bit of a pudgy sucker. I focused hard on keeping the CG forward during the build, which I achieved, however I blew my target weight by 27lbs. It's amazing how all of these little mods add up, even after the lithium battery weight saving. With two 170lb people on board and full fuel I'm limited to a baggage weight of 72lbs due to gross weight (1800lb) limits, and for aerobatics I'm limited to half tanks with two on board. In no loading case am I CG limited.
If I was to do things again, I would look at a lighter engine/prop combo (perhaps a composite sump and propeller, but stick to the 8.5:1 compression) and put it on a 320 engine mount. I would maybe ditch the interior primer and just fay seal everything with a modified silicone polymer (apart from the 6061T6, which I'd still prime). I guess I'll have to build another one...

Tom.
 
Last edited:
I completed the weight and balance on my RV-7 today . . . . .

So it appears I built a bit of a pudgy sucker.

Tom.

Pudgy, naaaah . . . Take off the paint and extra fuel and its pretty good!! With a pilot and 1/2 fuel, she will jump off the runway just after you get to full throttle!
 
Thanks Bill. Looking back at Van's statement on page 14-4 of the manual, it appears that they may have weighed the aircraft used in the example with no fuel on board instead of the unusable fuel, which we have to do here in Aus, so really I guess I'm only about 5lb over. I did try to keep the paint pretty light when I laid it down, with one layer of zinc phosphate etch then two medium coats of PU over that and just a couple of decals on top. I tried to think about weight the whole time I was building, however I also wanted to make something that would be useful, safe and would last the test of time.
Tom.
 
I'm starting to get the same feeling Fin. I shut the pump down at the first sound of it drawing air, which may have only been an air lock or something in the lines as this was the first time I had run the fuel system. I set the pickup as low as possible in the tank when I closed it up. Here's an excerpt from my log:

"Installed the fuel pickups into the tanks, ensuring they were in the right position prior to sealing through the use of a borescope through the fuel level sender port. Once this and the inspection panel was sealed in place with proseal, the fuel level senders were installed, again with proseal around the sealing face and the screws. #8 NAS1351 cad plated cap screws were used instead of Philips head screws so that future removal would be possible."

I posted on another thread regarding the Van's screens I am using (see link below). I think I will pump the tanks dry and check again the remaining fuel.
http://www.vansairforce.com/community/showthread.php?t=84544&page=2

Tom.
 
W&B

Rv7, tip up
O-360 carb, 2 Pmags
Hartzell cs BA
Dynon avionics, autopilot,
Full leather classic Aero interior, carpet
Fire extinguisher, glass break, smoke system tank installed behind passenger seat
Painted
B&G starter and alternator(heavy)

Total weight. 1,140. (#70 on the tail)
Has gained about 25 lbs over the last 15 years!
 
So yesterday, after my weight and balance, I had my first inspection by an A&P before I go for my final certificate of airworthiness inspection. This A&P (or L.A.M.E. as they like to call them here) discovered two rather important items. First was that my governor didn't hit the full fine stop (now rectified), and the other was that my wing root gascolator bowls were not tight and lockwired. The penny finally dropped this morning that this may be the cause of my excessive unseeable fuel issue. Thus I tightened both this morning and safety wired them, then re-ran the unusable fuel test, disconnecting the line at the fuel servo and pumping the respective tanks until the pump ran dry. The results were 60ml remaining in the right tank, and 45ml in the left tank. I'm not kidding. That Andair pump is a friggin hoover. That's less than two ounces of fuel remaining in the left tank. So it turns out that when the tanks got below 7 liters previously, the pump suction was so great that it started pulling air through the seal on the loose gascolator instead of fuel. I'm so glad this A&P discovered the issue, and since I've basically worked in a complete vacuum apart from VAF for the past 3 years, it's great to have a second set of eyes on things. Fortunately 22lbs is 9.97kg, so I can just re-calculate the CG impact instead of re-weighing things (CAO 100.7 6.3(a) stipulates that I must re-weigh if the change is greater than 10kg). Thus my final results are as follows:

Total zero fuel weight: 1113.6lb
Arm: 79.34"

Tail weight: 60.7lb.

The aft CG with two up, zero fuel and 100lb of baggage is still .5" within the limit so I'm pretty happy.
Thanks guys for helping me clear this up. Now I'm only 2.6lb over book weight, which isn't too bad considering this thing has more fruit than your local grocer.
Cheers,
Tom.
 
Baggage Capacity

First, I'm brand new to the forums though I've been reading them for several years.
I'm considering building an RV-7 or 7A...providing I can figure out how to ship it over here to the UK where I'm stationed without giving Her Majesty $6,000 in taxes...

As I read through this thread I'm noticing that Aft CG is a potential handicap of preventing one from carrying the 100lbs of baggage advertised by Vans. My wife an I together are around 300lbs, with 100 lbs of baggage and full fuel it seems we may be out of the aft CG envelope assuming IO-360, CS prop, IFR instrumentation, etc even though we'd be under max gross weight. Even if we were okay with full fuel, I'm assuming we would be well aft once fuel burns down after several hours of cruise.

Is this a design "problem", am I missing something, or is this something that can be mitigated by building carefully?

Greg
 
Baggage Capacity

Herb,

Do you know where I could get some ballpark weight and balance figures so I can run the numbers and make an estimate on how close I'd be to aft CG?

Greg
 
Your desired setup sounds pretty similar to mine, and with two old school FAA pax (170lb each), zero fuel and 100lb of bags, I'm 0.5" within my aft cg limit. This is assuming that you build with all options forward. My transponder is under the sub panel, my GPS antennas are in the engine bay, I have no aft mounted ELT and my AHRS are on the sub panel. I also laid down a pretty light paint job. Given that your combined pax weight is less, you should be fine, but I still stand by the fact that if I were to do it again I'd get a lighter prop/engine combo that my Hartzell BA and IO360-M1B setup an use the 0320 engine mount.
Tom.
 
Moves the entire engine 2” forward. Lots of nice space between engine and FW easy to work on. You need a 320 mount and 360 cowls. Have to graft 2” to the rear of the cowls is only issue. Vans should tell people they are going to have rear cog problems with parallel valve 360 engine and light prop and give them the option of a longer untrimmed 360 cowl and 320 mount. Alternatively some people have added spaces between 360 mount and FW to push it forward during build, my thought was might as well use the longer mount and fix the problem from the get go. Limited to composite CS options and might be difficult for me to ever mount a angle valve engine and Hartzel BA later without moving some weight back but that’s easier than the other way round and unlikely to ever happen.
 
Moves the entire engine 2? forward. Lots of nice space between engine and FW easy to work on. You need a 320 mount and 360 cowls. Have to graft 2? to the rear of the cowls is only issue. Vans should tell people they are going to have rear cog problems with parallel valve 360 engine and light prop and give them the option of a longer untrimmed 360 cowl and 320 mount. Alternatively some people have added spaces between 360 mount and FW to push it forward during build, my thought was might as well use the longer mount and fix the problem from the get go. Limited to composite CS options and might be difficult for me to ever mount a angle valve engine and Hartzel BA later without moving some weight back but that?s easier than the other way round and unlikely to ever happen.

I would have seriously considered this (w&b calculations) had I known weight would tend to be aft.

Bevan
 
Moves the entire engine 2” forward. Lots of nice space between engine and FW easy to work on. You need a 320 mount and 360 cowls. Have to graft 2” to the rear of the cowls is only issue. Vans should tell people they are going to have rear cog problems with parallel valve 360 engine and light prop and give them the option of a longer untrimmed 360 cowl and 320 mount. Alternatively some people have added spaces between 360 mount and FW to push it forward during build, my thought was might as well use the longer mount and fix the problem from the get go. Limited to composite CS options and might be difficult for me to ever mount a angle valve engine and Hartzel BA later without moving some weight back but that’s easier than the other way round and unlikely to ever happen.

If you build an aircraft and deviate from the manufacturers design, then you alone are responsible for the consequences of those design changes.

The 320 engine mount was designed for a 320 with FP prop, not the heavier/higher HP 360, again make those design changes at your own risk.
(installing an angle valve and CS on a 320 mount, proceed with caution is all I can say)
 
Last edited:
True, but the 360 mount was designed for the angle valve engine which is significantly heavier than the parallel valve most are using. The point is that a IO-360 parallel valve with a composite CS propeller (eg. WW200) is going to weight about the same or less than an IO-320 with a hartzell CS aluminium propeller, and significantly less than than an angle valve with a CS aluminium prop. I had 6,000hrs of build time to mull this one over, and would go a longer engine mount and composite prop with IO-360/340 if I was going to do it again. I'm a big believer in the Van's philosophy of keeping the weight down, but you still need to ensure the CG range is adequate to enable you to carry full bags. At the end of the day, whoever is going down this path needs to just run the numbers on their specific configuration. Not hard. Just a few minutes and an excel spreadsheet.

Tom
RV-7 IO-360M1B Hartzell BA CS prop
 
My RV7 with an angle valve engine and an MT prop weighs in at 1090Lbs with full IFR panel. The CoG is fine. I can do full fuel, wife, full bags and still be within limits.

I may take the strobe power unit out of the tail and replace with LEDs to save a bit of weight and move the CoG forward a bit.

I know the angle valve is not light, but it chucks out so much power, I love it! Well worth the weight I think. There is a noticeable difference in performance between a 180 and a 200. I would rather spend the weight on an engine than fancy leather trim ( I have no trim at all) or a heavy paint job.
 
Anyone with a IO 360 200 hp, with a Catto 3blade on a 7A? Does this combination help with weight and balance issues? Also how is take off and climb performance?
 
RV7A W&B Data:

Empty 1136 LM=412 RM= 426 Nose=298
Empty CG 80.10

Engine Mattituck w/FADEC TMXOF-360
Propeller Hartzell - C2YR
 
here comes another data point...

RV7 slider, not painted but fully primed internally, Dynon Skyview with AP and a bunch of steam gauges. IO-375 with backup alternator and Hartzell CS BA. Classic Aero aviator seats but minimal interior. ELT under the emp fairing, sunshades and 8 qts of oil.

L main: 520 lbs
R main: 511 lbs
Tail: 64 lbs
total empty: 1095
CoG: 79,8"

i'm a happy camper.

Cheers
Kay Stecklum
 
Last edited:
RV-7 Slider
IO-360M1B/ Hartzell BA Prop.
VFR single screen G3X touch, 1 comm
Basic interior, Vans seats, lightweight carpets
Painted
FlyLeds full lighting

R 511, arm 69.25"
L 511, arm 69.19"
TW 59, arm 249.75"

1081lb CG 79.07

This is in the envelope for all possible scenarios. In the aerobatic envelope with 2 up and about 3hrs of gas. I'm super happy. Now to keep it this way!
 
Last edited:
Hmmmm

So I’m planning
7A
Io 360 m1b thunderbolt
Pmags
Composite 3 blade fixed
Leather/synthetic full interior
Zip tips
Single 10” g3x with 375 dual axis autopilot
James cowl/plenum

Should I sincerely think about getting a 320 mount with this setup to avoid an aft CG????
Also, with the advancement in the nose gear design that vans now includes in the kits, does that help with the CG issue enough that a 320 mount wouldn’t be needed?
 
Last edited:
Am I calculating right?

RV-7 Slider
IO-360M1B/ Hartzell BA Prop.
VFR single screen G3X touch, 1 comm
Basic interior, Vans seats, lightweight carpets
Painted
FlyLeds full lighting

R 511
L 511
TW 59

1081lb CG 79.07

This is in the envelope for all possible scenarios. In the aerobatic envelope with 2 up and about 3hrs of gas. I'm super happy. Now to keep it this way!


I'm doing my own W&B calculations right now and thought I would double check myself by using my spreadsheet on some posted numbers. I get a different CG using the same numbers (using the calculations on page 14-6)
For these numbers 511, 511, and 59, I get 78.31, not 79.07.

Can anyone verify whether I am doing something wrong?

Using 68.45 for main gear and 249.19 for tail wheel arm, per the manual.

Thanks
Ivan
 
I'm doing my own W&B calculations right now and thought I would double check myself by using my spreadsheet on some posted numbers. I get a different CG using the same numbers (using the calculations on page 14-6)
For these numbers 511, 511, and 59, I get 78.31, not 79.07.

Can anyone verify whether I am doing something wrong?

Using 68.45 for main gear and 249.19 for tail wheel arm, per the manual.

Thanks
Ivan

You're correct. 78.31"
 
I would really recommend you measure those which is also per the manual. Mine were different from Van's.

Thanks, Jereme,

I saw that about measuring, but assumed (perhaps incorrectly) that measurements from Van's computer drafted plans would be more accurate than me with a plumb bob and a tape measure. I figured that things like the location of the landing gear was not subject to much error induced during the build.

What does anyone else think? Use van's moment-arm numbers or determine them your self?
=Ivan
 
Thanks, Jereme,

I saw that about measuring, but assumed (perhaps incorrectly) that measurements from Van's computer drafted plans would be more accurate than me with a plumb bob and a tape measure. I figured that things like the location of the landing gear was not subject to much error induced during the build.

What does anyone else think? Use van's moment-arm numbers or determine them your self?
=Ivan

I thought this too but did it anyways. I was glad I did, my mains were off by almost exactly half an inch. I thought this "this can't be right" so I measured it multiple times. My nose was also slightly off too. The gear go into welded items, anything welded is subject to a lot of movement, even if in the same welding jig.
 
Last edited:
Thanks, Jereme,

I saw that about measuring, but assumed (perhaps incorrectly) that measurements from Van's computer drafted plans would be more accurate than me with a plumb bob and a tape measure. I figured that things like the location of the landing gear was not subject to much error induced during the build.

What does anyone else think? Use van's moment-arm numbers or determine them your self?
=Ivan

Sorry to be late to the party, but I can confirm the difference comes from different measured Arms on My airplane. I measured Right main at 69.25, Left main 69.19, tail wheel 249.75. These were double checked by others. Perhaps going forward it would be useful to include arms in these weight and balance posts so future builders can get an idea of the differences we are seeing.

I'm not sure why there are differences, but the RV-7 fuselage is far from fully matched hole, with most of the forward fuselage requiring sub structure to be drilled, and of course we have hand shaped longerons. And I'm sure the tolerances on the welded engine mount are not perfect. A number of small differences will add up.
 
First let me say thanks again Jereme and Ed for telling me to go back and measure my moment arms and not just use the figures from the construction manual. Like you, my gear measurements were different. Here's what I got after measuring it a couple of times using different tools and having others double check me:

Right man 69.25, left main 69.375 and tail wheel 249.31.

That puts my main gear about 3/4" further aft than Van's sample numbers. That is enough to make a difference. So let me reinforce the point that you need to carefully measure your own moment arms.

Here's what I came up with for weight and CG:

Rt man 524.3, Left main 521.8, tail wheel 66.8

Total empty weight 1113 lb. Empty CG location 80.12. That's heavier than I had hoped for (aren't they all?) but entirely workable. We can top off the tanks, put my wife and I and 100# of baggage in it and still be within both max gross and CG limits.

Now on to get it licensed and flying!
 
Should have included details on the plane. RV-7 Slider. Io-360, Sensi metal FP prop. Single screen Dynon, full interior, painted.
 
Be Carefull

Total empty weight 1113 lb. Empty CG location 80.12. That's heavier than I had hoped for (aren't they all?) but entirely workable. We can top off the tanks, put my wife and I and 100# of baggage in it and still be within both max gross and CG limits.
Now on to get it licensed and flying!

Don't forget that the CG moves aft as fuel is burned. Remember to calculate where the CG will be with minimum fuel at the end of the flight.
 
Thanks, Mel. Great point. I did those calculations too. And you are right. CG moves aft as fuel is burned. In our case, if we take off at max gross and burn down to VFR minimums, we are still within the allowable aft limit. Not by a lot, but still within. That's as long as the combined pilot and copilot weight are moderate, under 335 lb. With heavier people, we would have to limit baggage to stay with the aft CG limit.

thanks
 
Empty Weight: 1189
Empty CG: 79.62

Full paint, fire extinguisher, full Classic Aero interior, IO-375, 2 qt oil accumulator, Whirlwind 300 prop, full Garmin glass, 6 quarts oil in the engine, 1.5 in the accumulator.
 
W & B

R/H Main Wheel 426 lb (193 Kg)
L/H Main Wheel 444 lb (201 Kg)
Nose Wheel 240 lb (109 Kg)
Total Weight 1,110 lb (503 Kg)
Empty CG 82.07 in (2084 mm)

The weight on the nose wheel is on the light side which is caused by the Catto composite propeller and spinner plus the EarthX lithium battery. Though I do have a Saber 16 lb Crush Plate (i.e. a 20 lb one with a hole machined in the middle for the Catto spinner) retaining the prop which has compensated but not to the level I was expecting.

The CG is further back than I was hoping which has limitations in relation to luggage and passenger weight with minimum fuel on board.

So back to the options available. One option is to replace the EarthX battery (i.e. weighs 1 Kg) with the heavier Odyssey PC 680 battery (i.e. 7 Kg) which is an easy weight gain option.
 
V2:
Empty weight: 1,115
Empty CG: 77.89
Left: 532
Right: 528
TW: 55

Empty it is forward of CG but with any weight added (for example 5 gal & 100 pilot which is not me!) it falls within range and will give me full loading options.

“Chino” paint job - I.e primer fiberglass and bare aluminum, James cowl, extended hub Hartzell, leather seats, full carpet, slider Sika bonded. Was hoping for under 1,100 but happy with the loading options. Hard to get out CG range as it stands. DAR inspection Thursday then fly it!!!
 
Last edited:
RV-7 N159LG
Right Wheel: 480lb
Left Wheel: 490.5lb
Tail Wheel: 70.1lb
Empty CG = 80.59"
Total: 1040.6lb

Its tail heavy as expected so I placarded the baggage @75lb's.
Primed fiberglass but otherwise unpainted. I0-370, dual P mags, AFPFM150, Catto 3 blade w/nickel leading edges, Dual Dynon SkyView, Roll & Pitch Autopilot, Garmin 355, Garmin intercom, manual elevator trim, classic aero sportsman seats, carpet under seats and feet, Sam James cowl, home-brew plenum, 11 row cooler, heated pitot, earthx680, stubby wingtips, larger 380 tires.

I'm pretty happy with the results. Paint will probably add another 25-30lbs for an all up weight of around 1070.
 
Last edited:
Back
Top