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Restriction removal denied

R

Ron B.

Well Known Member
We have flown off our 25 hr and had hoped to have our restrictions removed today. Instead we got a call from a Superintendant at Transport Canada that our C of G is too far aft. And he will not remove the restrictions as is. He has also passed it by his supervisor in Ottawa.
Here our details, I realise we are very heavy, but we expected to pay the penalty in capacity, not grounding the plane.
Right wheel 683 lbs.
Left wheel 699 lbs.
nose wheel 336 lbs.
our empty C of G is 109.52" to the datum. (99.44)
Changes to our RV to me don't add up to the center of gravity change we are experiencing.
We have an electric Ray Allen rudder trim. Two 680 batteries where the Concorde battery was to be placed. Van's said one Concord would be heavier than two 680s. Dynon auto pilot servo mounted as per Dynon.And the two ADHRS are mounted above the battery location. Our paint is probably heavy and all parts were primed (interior as well).
We have a Flightline interior (leather seats).Sound Down insulation arround cabin area. Aerosport overhead console, arm rest, and quadrant console. Lastly a fair amount of Polyfiber fil was used to make a smooth transition from glass canopy to alum tail.
One of my build partners says this is what is giving us an aft C of G. He must be right but I'm having trouble believing that we are the only ones with an aft C of G as that is what Van's said today. They believe we have an error in weighing or in our calculations.
My question is that this superintendent e-mailed us stating that our RV must be able to load up 150 lbs in the baggage compartment , two standard males (193 lbs in Canada) a pilot and perhaps a co-pilot if our gross weight limit allows and not exceed our C of G. He adds in all the aircraft he has dealt with,they add ballast if needed to guarantee you can not go over the aft center of gravity. We think this is hog wash as a Cessna 172 for one can be over the rear C of G . If all AC had this feature why would we have to do a weight and balance?
My specific question is for the flying RV-10 . Can you load your RV-10 (without going over gross and over max baggage 150 lbs) and exceed the aft C of G limits? I'm not talking about flying it that way, just asking if it's possible to do? I think I know the answer.
Thanks Ron
 
Van's says the baggage compartment limit is 100 pounds. Are the Transport Canada officials aware of that? I have the Flightline AC airconditioning system in my tailcone and my empty CG is 109.37. I, too, suspect you might have a weighing error of some kind. What are the Arm measurements on your landing gear? I plugged your numbers into the gear Arms on my airplane and came up with an empty weight of 1718 and an empty CG of 108.03.
 
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P.S., I can put two 195 pounders in the front seats, 100 lbs in the luggage area, and full fuel. This puts me close to max GW due to my heavy airplane, but the CG is nearly four inches forward of the aft limit.
The more I look at this, the more I agree with Van's that there has been some kind of error in calculations, measurements, or weighing.
 
Hi David
Could you list the additional items (other than Van's supplied) you have aft of your center of CG point.
We have probably more painted surface aft of CG center? Skyview auto pilot servo and two ADHRS mounted above battery location, rudder trim tab and Ray Allen servo, Aerosport overhead console and fairing for smoothing it out and center armrest console and quadrant console, Flightline interior with leather seats,and Soundex interior insulation kit. Two 680 rather than one Concord battery and two soleniod rather than one.
Thanks Ron
 
TruTrak autopilot servo, Pinpoint GADHARS, Chelton magnetometer on the aft deck below the vertical stab, Dual Vertical Power Control Units and Vertical Power Climate Control Unit next to the battery, Odyssey 925 battery, Flightline Interiors leather interior, armrest console, SafeAir1 Extended Range tip tanks, external power plug, Flightline AC air conditioning system aft of the baggage bulkhead,(that alone should give me a CG further aft than yours) Flightline AC overhead console, and Aerotrim electric rudder trim. I have a full custom paint job. I can't imagine I have significantly less paint aft than other -10s and I have a very smooth fiberglass to aluminum transition that required lots of filling.
What are the measurements aft of the datum for your main and nose gear?
 
Thanks David
Our mains are 123.94 each and the nose is 50.19. Your's should be farther aft than ours due to the A/C unit. Do you know how much it weights? Your battery should be over 6 lbs lighter. Do you know which concord battery Van suggest?
 
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My mains are right 123.44, left 122.99 and nose gear 47.44. The aft air conditioner equipment weighs around 30 lbs.

It looks like your nose gear is almost three inches further aft than mine. That moves your CG about 6/10 of an inch aft.

In spite of that, I think if you stick to the Van's design limit of 100 pounds in the baggage area, you should be just fine. Does Transport Canada require you to figure it with 50 per cent more luggage than the design limit or something like that?
 
We may have gotten the bagage limite wrong. But that is not his only concern.We might have trouble satisfying him?
 
Well, with two 193 pounders in the front seats and 100 lbs. in the baggage area, you should be well forward of the aft CG limit of the airplane. I don't see how they can ask you to put more weight in the baggage area than the design limit.:confused:
I hope you get it worked out.
Good luck and let us know how this plays out.
 
If that nose wheel is that far aft then there has to be some additional weight in the back due to something. Flying nose heavy in an RV-10 is fine. Tail heavy planes can be very interesting to fly. The RV-10 elevator size and the momnet arm of the elevator can probably handle tail heavy flight but you can really get yourself into some serious trouble stall and spin wise. You should still be inside the envelope though. When you say polyfiber fill are you talking Bondo or something like West systems and fill?
 
I ran into a similar problem you had though except in the reverse. Luckily the powers to be understood aircraft loading. Practically any plane can be put out of CG if you don't load it correctly. Gulfstreams are out of CG when empty. The easiest way to get them off you back is to put a few pounds at the nose of the plane( not the best way IMHO.) Do you have a spread sheet showing all loading conditions?
 
If I had to guess: (sorry for being presumptious... You weighed it wrong. You need to LEVEL the airplane before you will get proper weight readings.
Also, you made no mention of what prop you used.
Tim
 
Thanks for the responces , it's what we need (help). Our next step is to weigh it again and start fresh. We had a 4' carpenters level on one inch blocks from one door sil to the other. Blocks were to clear the lip for the door seal. Checked the level by flipping it end to end to make sure it's true yesterday. We used a 2' level on same door sil for and aft.
We have a blended airfoil Hartzell prop purchased from Van's.
Thanks again Ron
 
Ron, from your last reply it sounds like you had the wings level. The important issue here is was the aircraft level in pitch. If it is just sitting there in the hangar parked it will be in a nose up attitude which will cause the CG to shift aft when it is weighed in that mode.

Martin Sutter
Building and Flying RV's since 1988
EAA Technical Counselor
 
Ron B. said:
Thanks for the responces , it's what we need (help). Our next step is to weigh it again and start fresh. We had a 4' carpenters level on one inch blocks from one door sil to the other. Blocks were to clear the lip for the door seal. Checked the level by flipping it end to end to make sure it's true yesterday. We used a 2' level on same door sil for and aft.
We have a blended airfoil Hartzell prop purchased from Van's.
Thanks again Ron
Click to expand...

Then maybe the scales you used have an error.

The empty weight of your airplane is about 120 lbs heavier than a basic equipped RV-10. Depending on where that extra 120 lbs is distributed, it could easily effect the C.G. in a negative way. That being said...the first thing I would do is reweigh... very carefully. Double check the wheel position measurements (a 3" difference in nose wheel position is very unlikely from one RV-10 to the next) Missing the proper level point by even a small amount can have a measurable effect on the empty c.G. position. You could help a little by doing the re-weigh with the maximum 12 qts of oil in the engine (just set bottles on top of the cowl).

One thing that sounds totally strange to me...the superintendent says you need to be able to put 150 lbs in the baggage area, two standard (Canadian) passengers in the back seats and just a single pilot in the front? Is that correct? It would be very strange to load an airplane that way but if that is what he wants, I would request that he show you a few standard category aircraft that can load the baggage area to it's max rating, put standard size passengers in the back two seats and just a single pilot in front, and still be in C.G. A few probably can, but not many. Can't do it in a C-172.

Your 150 lb baggage limit isn't helping you any either. You may or may not have tried to sneak this by them because of your expected higher empty weight, but Van's specified baggage area limit shown here is 100 lbs. Changing that, and getting some slightly different #'s from a re-weigh might get the superintendent what he wants.
 
Martin Sutter said:
Ron, from your last reply it sounds like you had the wings level. The important issue here is was the aircraft level in pitch. If it is just sitting there in the hangar parked it will be in a nose up attitude which will cause the CG to shift aft when it is weighed in that mode.

Martin Sutter
Building and Flying RV's since 1988
EAA Technical Counselor
Click to expand...

He said "We used a 2' level on same door sil for and aft. "
 
rvbuilder2002 said:
Then maybe the scales you used have an error.

The empty weight of your airplane is about 120 lbs heavier than a basic equipped RV-10. Depending on where that extra 120 lbs is distributed, it could easily effect the C.G. in a negative way. That being said...the first thing I would do is reweigh... very carefully. Double check the wheel position measurements (a 3" difference in nose wheel position is very unlikely from one RV-10 to the next) Missing the proper level point by even a small amount can have a measurable effect on the empty c.G. position. You could help a little by doing the re-weigh with the maximum 12 qts of oil in the engine (just set bottles on top of the cowl).

One thing that sounds totally strange to me...the superintendent says you need to be able to put 150 lbs in the baggage area, two standard (Canadian) passengers in the back seats and just a single pilot in the front? Is that correct? It would be very strange to load an airplane that way but if that is what he wants, I would request that he show you a few standard category aircraft that can load the baggage area to it's max rating, put standard size passengers in the back two seats and just a single pilot in front, and still be in C.G. A few probably can, but not many. Can't do it in a C-172.

Your 150 lb baggage limit isn't helping you any either. You may or may not have tried to sneak this by them because of your expected higher empty weight, but Van's specified baggage area limit shown here is 100 lbs. Changing that, and getting some slightly different #'s from a re-weigh might get the superintendent what he wants.
Click to expand...

I think you misread Ron's original post. Nothing about back seat pax. Two 193 pounders in the front and 150 pounds in the baggage. The nose wheel being further aft (either mis-measured, or actually further aft) and putting 150 lbs in the baggage compartment are causing this issue. 100 lbs in the baggage, even with the nose wheel further aft, would keep the CG within limits according to my calculations.

$.02 worth
 
dmaib said:
I think you misread Ron's original post. Nothing about back seat pax. Two 193 pounders in the front and 150 pounds in the baggage. The nose wheel being further aft (either mis-measured, or actually further aft) and putting 150 lbs in the baggage compartment are causing this issue. 100 lbs in the baggage, even with the nose wheel further aft, would keep the CG within limits according to my calculations.

$.02 worth
Click to expand...

You might be right, but what he said is...

Ron B. said:
My question is that this superintendent e-mailed us stating that our RV must be able to load up 150 lbs in the baggage compartment , two standard males (193 lbs in Canada) a pilot and perhaps a co-pilot if our gross weight limit allows and not exceed our C of G.
Click to expand...


He wrote, two standard males, a pilot and perhaps a co pilot.
The "perhaps" part threw me into thinking... In addition to the two in back, a pilot, and perhaps a co-pilot if weight limitations allowed.

I haven't pluged the #'s into a spread sheet but I find it hard to understand why an RV-10 with two 190+ pounders in the front seats, couldn't carry 150 lbs in the baggage if the rear seats are empty
 
On my airplane, which is fairly close to Ron's empty CG, to get to the aft CG limit for my FAA paperwork, I had to load one 220 lb. pilot, 300 lbs of pax in the back seat, 50 lbs of baggage, and 21 gallons of fuel. That kind of odd load puts me right at the aft CG limit.

My airplane, with an empty CG that is very close to Ron's, has a CG of 114.02 with two 195 pounders up front, and 150 pounds in the baggage area. That is over two inches forward of the aft CG. So, maybe you are right and they do want some weight in the back seats. Ron's post was not too clear on that point.
 
Ron B. said:
(...)
we got a call from a Superintendant at Transport Canada that our C of G is too far aft. And he will not remove the restrictions as is. He has also passed it by his supervisor in Ottawa.
Here our details, I realise we are very heavy, but we expected to pay the penalty in capacity, not grounding the plane.
Right wheel 683 lbs.
Left wheel 699 lbs.
nose wheel 336 lbs.
our empty C of G is 109.52" to the datum. (99.44)
(...)
My question is that this superintendent e-mailed us stating that our RV must be able to load up 150 lbs in the baggage compartment , two standard males (193 lbs in Canada) a pilot and perhaps a co-pilot if our gross weight limit allows and not exceed our C of G.
(...)
He adds in all the aircraft he has dealt with,they add ballast if needed to guarantee you can not go over the aft center of gravity.
(...)
Thanks Ron
Click to expand...

Hi Ron,

first of all I have no idea if your empty CG is really aft or not - I have no clue about the RV-10.

It seems that the representative of TC (Transport Canada) had something of FAR 23.25 (Weight limits) in mind:

(a) (...) The maximum weight must be established so that it is--
(...)
(2) Not less than the weight with--
(i) Each seat occupied, assuming a weight of 170 pounds for each occupant for normal and commuter category airplanes, and 190 pounds for utility and acrobatic category airplanes, except that seats other than pilot seats may be placarded for a lesser weight; and
(...)
(B) At least enough fuel for maximum continuous power operation of at least 30 minutes for day-VFR approved airplanes and at least 45 minutes for night-VFR and IFR approved airplanes; or
(ii) The required minimum crew, and fuel and oil to full tank capacity.
(...)

This paragraph applies to weight, it can be inferred that the given circumstance should also apply to CG limits. Although I do see no reference supporting such a ruling, neither in the requirement nor in the guidance material (AC 23-8B, Flight Test Guide in this matter).

So try to figure out if your maximum weight and CG limits are adequate to cover the above loading. If so, talk to your TC representative and ask if he has other reasons.

One note about aft CG limits. As your CG approaches the neutral point of your a/c, the aircraft gets less stable. This can lead to a severe degradation of stall characteristics among other things. So procede carefully if you want to extend the aft CG beyound what others (Vans) have set.

Last note about requirement. I know that experimental aircraft are exempt (to a certain degree) from showing compliance to the appropriate airworthiness requirements, but different countries handle the degree of exemptions very differently. And in my opinion, it can't hurt trying to adhere to some of the requirements, especially if they are easy to do.

Cheers


Thomas
 
OK , to clarify , we made a mistake and somewhere got the idea that the max baggage was 150 lbs. It's 100 lbs.
What the superintendent wants to see is our RV-10 with now the 100 lbs in the baggage area (this reduction will help a lot but not solve our situation), is not being able to exceed the rear C of G limites by loading 100 lbs of baggage, two standard males (193) in the rear seats and what ever you can think of for fuel and front passengers and Pilot of coarse. While the combination does not exceeding the gross weight. A 172 cannot meet these requirements.
 
Nor does...

Ron B. said:
OK , to clarify , we made a mistake and somewhere got the idea that the max baggage was 150 lbs. It's 100 lbs.
What the superintendent wants to see is our RV-10 with now the 100 lbs in the baggage area (this reduction will help a lot but not solve our situation), is not being able to exceed the rear C of G limites by loading 100 lbs of baggage, two standard males (193) in the rear seats and what ever you can think of for fuel and front passengers and Pilot of coarse. While the combination does not exceeding the gross weight. A 172 cannot meet these requirements.
Click to expand...

...my Tiger - perhaps he should de-certify those in Canada too...:eek:
 
We had to supply Transport Canada with numerous W and B senarios from the get go. Max forward cg max aft and each senario had to allow for landing with minimal fuel. They all fell within the limits but we didn't have max weight in all positions as the Cof G would not allow it. Nothing different than a 172 . We do acknowledge we have a aft cg . It does affect our capability. We are thinking of moving one 680 battery forward of the firewall. Unless we find a mistake in our weight or measurement.
Ron
 
One last thing for today. We were not trying to add aditional weight in the baggage , it was a mistake. We are not trying to get by and fly with a farther rearward c of g range. We just what to fly with the Van's prescribed c of g limit. Before the Transport Canada issue we discussed moving the battery to give us more utility.
Thanks for the ideas
Ron
 
Ron when you are weighing your plane make sure that the hanger doors are shut and there is no breeze on the plane. This can shift the weight dramatically and give you false weights. Good luck with TC or the MD-RA
 
So Canada defines scenarios...

Ron B. said:
We had to supply Transport Canada with numerous W and B senarios from the get go. Max forward cg max aft and each senario had to allow for landing with minimal fuel. They all fell within the limits but we didn't have max weight in all positions as the Cof G would not allow it. Nothing different than a 172 . We do acknowledge we have a aft cg . It does affect our capability. We are thinking of moving one 680 battery forward of the firewall. Unless we find a mistake in our weight or measurement.
Ron
Click to expand...

...for home built planes that are not included in the US Certification per Part 23?

Time to buy them a tuque to keep their brains warm and active...:D
 
Ron B. said:
One last thing for today. We were not trying to add aditional weight in the baggage , it was a mistake. We are not trying to get by and fly with a farther rearward c of g range. We just what to fly with the Van's prescribed c of g limit. Before the Transport Canada issue we discussed moving the battery to give us more utility.
Thanks for the ideas
Ron
Click to expand...

I wasn't meaning to accuse you of that Ron. Just raising the question as to the difference since I am pretty sure they require you to use the #'s specified by the designer.
 
Ron moving a battery forward is a great idea but just make sure it has a good secure spot and good secure battery connections. The first RV-10 lost was more than likely caused by moving the battery forward and not making the proper connections. From you posts I doubt you will make the same mistake. Good luck.
 
Scott I wasn't implying anything, I was just clearing the air and admitting we had made a mistake on the 150lbs baggage capacity. I appreciate all the comments trying to solve our situation.
Thanks everyone, keep the questions coming. We are planning on re-weighing on tuesday.
Norman, we had the hangar doors closed I do believe. They will be closed next time. I do recall the numbers staying constant as in not jumping up and down at all.
Thanks Ron
 
Re did our weight and balance. Used three certified scales used every day in commerce. Actually had to wait til noon because they were in use and had to return tonight as needed at 7 tomorrow. Leveled the aircraft for and aft. Closed the hangar door. Same results as we expected. We did get the empty CG to move forward .30 of an inch. Probably because we knew which way to lean with discrepency. It's obvious that our extra weight is aft. More painted area, extra battery, autopilot servo, rudder trim and servo, Soundown insulation, rear window close outs (fiberglass), Flightline interior, bagage door closer, ELT, etc.
We removed the two 680 batteries and the two solenoids along with the # 2 wire including the battery mount, and temporary mounted them to the front of the firewall.While typing this I thought I remembered the empty CG but it's late and I'm just getting home from a Pilot's safety seminar. I'll have to do like the television and say "to be continued". It's too late here to go to the hangar and retrive that info.
Sorry Ron
 
Our new empty C of G is now 106.8 ". We also discovered how we came up with a bagage limite of 150 lbs. It came directly our of the documents we recieved from Van's Aircraft pertaining to weight and balance. Second page third paragraph. Our tail kit was purchased in Feb. 08 and the subsequence kits were purchased thereafter. Van's must have changed their minds after we recieved our documentation?
Anyone have experience mounting batteries to the firewall of an RV-10, pictures?
Thanks Ron
 
Moving battery?

Ron,

I do hope you find e better way to deal with this than to move the battery.
Mine will be almost identical and buillt mostly to specs except for some upholstery and overhead console.
I just can't see why you are the only one that has to move the battery forward. As I said, I simply don't understand it.
Please keep us updated.
 
Ron B. said:
Anyone have experience mounting batteries to the firewall of an RV-10, pictures?
Thanks Ron
Click to expand...

I only know of one instance of somebody moving the battery forward of the firewall. Unfortuantely, that turned into a very tragic incident. Neither the aircraft or pilot are still with us.

With that said, the problem wasn't due to w&b.
 
Your new CG number sounds like a normal RV-10 CG. Be careful that moving a battery to the firewall doesn't leave you with an airplane that will require carrying aft ballast when only the front seats are occupied. Most standard -10s seem to be a bit nose heavy and your numbers look like that might be the case for you.
Your airplane does not seem to have any unusual equipment installed and your new CG number seems to agree.
Have you talked to any of the other RV-10 builders in Canada to find out if this requirement to put two 193 pounders in the back seat is common with Transport Canada? Something just isn't right here.:confused:

I bought my kit in the spring of 06 and I don't recall seeing any baggage number other than 100 pounds. What is the document that mentions 150 lbs?
 
It's the actual weight and balance document, dated 2/4/05. It's the document that describes empty weight, gross weight , max gross weight and payload etc. It describes how to weigh your aircraft.
We will probably have watch our forward CG when no rear passengers. Perhaps as Tim O mentioned with our first aid kit, spare oil and a few tools we will be OK. We will have to crunch the numbers.
Ron
 
In Canada, as the builder, you are the manufacturer and can set the limits. What effect would reducing your placarded baggage weight to 100 lbs have? Enough to let you put the battery back where it was, and then get numbers more like other RV-10's? Just thinking out loud here.

Otherwise, i'll guess you've checked that you're not smuggling a family of squirrels in the tailcone somewhere...
 
Ron

I am coming into this debate quite late, and not read every post but here are my thoughts for what they are worth.

One caveat.....our rules are very closely modeled on the FAA and I expect your rules are too, but there may be some differences on getting your Cof A.

1. They have no right declaringing your CofG is not acceptable in the first instance.
2. The CofG range for the RV-10 is something like 107.84" - 116.25" Aft of the datum (make sure your datum is good)
3. Our empty CofG is 108.58" and your original one is 109"........SO WHAT'S THE PROBLEM
eusa_wall.gif

4. Time for you to find some folk with a brain and common sense. Do not go moving batteries and rewiring your perfectly balanced RV10 just because of some moron who thinks he knows more than Vans.....and the rest of us. heck we signed ours out at 2900lbs too!:)

All the best with your battle.

DB :cool:

PS Just did a quick calculation at your CofG and with 2 95kg folk up front, one in the back and 100lbs (Vans number) you are still in the CofG range with full fuel. You MTOW limit might have to rise to 2900lbs though! And they do it easily!!
 
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I agree that our original C of G was do-able. But with a empty C of G of 106.8 we have many more practical options for loading. Other than the work of moving the batteries and perhaps a little balast in the bagage when no rear passenger seats are occupied, what other downfalls are going to encounter?
Ron
 
Ron, if you are happy doing all that work to achieve a certain result, good for you, but the idea some Dept of Transport guy can refuse lifting your phase 1 test flight restrictions because the CofG is ...errr in the acceptable zone.....is outright criminal.

For that matter they should be ashamed for not insisting at issue of the CofA to begin with.

Battery position shown above by John....That looks great now, until you have the aircraft completed, all the wiring, cables and brake lines installed. How on earth will the battery ever be removed?

Maybe its been done before but I have some serious concerns with that.

DB:cool:
 
RV10inOz said:
Battery position shown above by John....That looks great now, until you have the aircraft completed, all the wiring, cables and brake lines installed. How on earth will the battery ever be removed?

Maybe its been done before but I have some serious concerns with that.

DB:cool:
Click to expand...

Actually it's not hard at all. The tray is two angles, outermost on hinges. Remove the bolts, outermost drops down. Slide battery forward, and it drops into your hands behind the pedals. Connection is a Moroso dual quick disconnect plug. See photo (sorry for the out of focus on the plug).

John

1zy8txe.jpg
[/IMG]
 
Hopefully we are not going into no man's land as we were contemplating mounting them on the forward side of the firewall, in the engine compartment. The 172 in our hangar has it's battery in the same location, (opposite side).
Ron
 
Well I admire your work.......but you have not a complete aircraft there. Its gets a lot more interesting when the whole thing is together, seats in panel in etc etc.

Not saying you can't do it, but its not going to get any easier either.
 
RV10inOz said:
Well I admire your work.......but you have not a complete aircraft there. Its gets a lot more interesting when the whole thing is together, seats in panel in etc etc.

Not saying you can't do it, but its not going to get any easier either.
Click to expand...

Coming in a bit late but reading since it posted...your numbers are there but you need to "finish" the aircraft. If not, you need to do the W&B in the current config, Mine was right on, as others have posted. Work up the scenarios for various configs and present them..I don't need ballast, Two people in the back makes it a tad faster because of less trim, and the airplane perforns well in all renages of the CG..BUT I do calc my W & B each flight, but I never had an issue either. Gotta love the AFS 3500 for making those calcs EASY!!! Don't move the battery, waste of time and effort.
 
Looking at your weight and balance, I would say there is nothing "wrong" with its current location. It is slightly back from the forward CG limit when empty, which is no big deal. There is absolutely no reason Transport Canada should have an issue with this, and I suspect it is a lack of understanding / experience with your contact there.

Even if you get the empty CG slightly forward of the forward limit, there are W&B scenarios that put you at aft CG prior to reaching gross weight. Put 100 lbs in the baggage, a pilot, and the remainder in the back seat until you hit gross, and you will be past aft CG. This is not unlike other production airplanes ... that is the point of performing a weight and balance. The CG on my RV-10 is near the forward limit, but there are real life scenarios I can't fly due to aft CG.

With all of that said, there is no reason you can't mount the battery on the forward side of the firewall if it makes you feel better, and is less of a problem that dealing with T.C. The RV-8A typically has the battery mounted on the forward side of the firewall, including mine. Original Odyssey battery is 6 years old and 400 hours with no problems. A side benefit is the short cable run to the starter, which gives better starting performance due to reduced cable loss at high current. Many people have commented they can't believe my small battery starts the engine, but with 2 feet between the battery and starter, the losses are low. Van's makes a firewall mounting tray that you could buy if you don't want to fabricate your own.

After crawling under the panel in the RV-10 with seats installed, I would strongly caution against putting the battery behind the firewall. Takes up prime real estate if you have a complicated panel, its hard to reach, and there really is no down side to having it located forward of the firewall.

Aaron
 
Thanks for your replies. We start re-mounting the batteries tomorrow. I did not realize the RV-8 had it's battery located firewall forward.
Thanks Ron
 
After crawling under the panel in the RV-10 with seats installed, I would strongly caution against putting the battery behind the firewall. Takes up prime real estate if you have a complicated panel, its hard to reach, and there really is no down side to having it located forward of the firewall.
Click to expand...

Thanks for confirming exactly what I thought too......having been under my panel to get to connectors for Dynon updates.......let alone a battery!
 
We are off tomorrow for our first cross country in our RV-10. We finished up on moving both batteries on the forward side of the firewall. Our empty C of G is now 107.29". Our Transport Canada man, came in while he was on vacation and drew up our documents today. I was not expecting anyone working for Transport Canada to do that. Much appreciated. I also did not think issueing a Special Certificate Of Airworthiness was a one man deal, I thought someone else would also be qualified to do so, somewhere in Canada. He was happy with the changes and we are moving on.
We are planning on a trip to Charlottetown PEI. , a one and a quater hr. flight each way. Or an all day trip in our Supercubs!!!
Thanks to all for all the help.
Ron
 
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