Anyone have any experience in a later model 24 volt Cessna 185 moving the battery up front?

I got a quote from Beegles, but I'm not certain who else has done it, or how it will work.

-Brad

mtv wrote:Buy an Odyssey battery. NO box required, since the battery is sealed. No vent, etc. Just a bracket to mount the battery.

And, they crank like crazy.

Remember, folks, your EMPTY CG does not have to fall within the airplane's CG envelope. All you really care about is where the CG resides in various LOADED conditions, including of course, where it is in worst case for flight, which is pilot, min fuel and survival gear.

If you can get the plane within the forward limit in that case, you're good.

The Avcon conversion of the Cessna 170 puts a Lycoming O360 in the 170,and it DOES NOT require moving the battery aft. My airplane has the battery on the firewall, and even before I converted to the Odyssey, it was well within the forward limits.

MTV

Anybody have a copy of a field approval they want to show how it's done?

So out of everybody out there that's encouraging get a F/A nobody has an example of one? Does that mean it hasn't been done? Or nobody's willing to share?

If you want, I can take some pictures of the Burl's firewall mounted battery box.

Jr.,

The battery box on the 1952 170 is on the firewall, upper right. Avcon didn't move it, as far as I know.

MTV

Glidergeek wrote:So out of everybody out there that's encouraging get a F/A nobody has an example of one? Does that mean it hasn't been done? Or nobody's willing to share?

I believe 182STOL has copies of field approvals to approve the box he sells. I have no idea about any other "field approval required" battery boxes. I do know the FAA has been receptive to field approval requests for his box, because he has demonstrated to them that it is well built and a well thought-out installation.

Of some note (and sorry for the thread drift), everyone hears horror stories about the FAA denying field approvals these days. There was an actual, valid reason they became upset about field approvals and a valid reason why they had to adopt a less friendly attitude about them. The reason was that FAR too many people were pushing stuff through on 337's that really needed to be looked at a lot closer than a quickie field approval. Major modifications that easily could negatively affect flight safety... stuff that could cause a change in the way the airplane flies... primary control and primary structure stuff. "We" (the airplane tinkerers and modifiers) did this to ourselves.

But I was just recently peripherally involved in a field approval getting done (for a particular device unrelated to batteries) on a Maule, and it went very smoothly. The trick is good documentation and making a legitimate case to prove your claim that it will be safe.

If my customer had sent in a 337 form just saying "we want to install this device on this airplane", the folks at the FAA would have had no reason to believe it was or was not safe. But THEY would have been put in the position to ascertain if and why it was safe. That's a lot of work for them, they're not familiar with stuff like this the way they used to be, and they have to be "suspicious" by their sworn job description.

So what made this go smoothly is that I wrote out a full explanation of the benefit that justified a field approval, why it was safe to do so, and I laid out the specific risks or "failure modes" that could create an unsafe modification. I also gave the FAA a specific indication of what factors and details I would suggest their ASI (field inspector) should look for, when making a decision whether this was a high risk or low risk modification.

Assisting them in how to make this safety determination, as well as showing good faith and conservative thinking towards safety, made the FAA comfortable with what we were asking. So their attitude changed from "why should we take a chance on allowing something like this to be done?" ... to... "they showed us why it is a safe, low risk thing to do... there's no reason we should deny this."

So it takes extra time and effort to get something through on a field approval, compared to an STC approved mod. But it is certainly not impossible.

Glidergeek wrote:So out of everybody out there that's encouraging get a F/A nobody has an example of one? Does that mean it hasn't been done? Or nobody's willing to share?

I have had the grand total of two, count 'em two, field approvals done. On both of them, the IA I was working with contacted his PMI (FAA inspector) and ran the proposed mod by him. After getting the go-ahead, we went ahead & did the work, wrote it up, and got it signed off. So IMHO it is critical to have a good IA to work with, and also critical that he be on good terms with his PMI & that they both have experience and/or are comfortable with doing field approval mods.

hotrod150 wrote:

Glidergeek wrote:So out of everybody out there that's encouraging get a F/A nobody has an example of one? Does that mean it hasn't been done? Or nobody's willing to share?

I have had the grand total of two, count 'em two, field approvals done. On both of them, the IA I was working with contacted his PMI (FAA inspector) and ran the proposed mod by him. After getting the go-ahead, we went ahead & did the work, wrote it up, and got it signed off. So IMHO it is critical to have a good IA to work with, and also critical that he be on good terms with his PMI & that they both have experience and/or are comfortable with doing field approval mods.

I have SOLD One Hundred and twenty one (121) Firewall Mounted Battery /boxes in last 10+ years all over the Country and World . I'm retired U.S. Army to pay my regular bills -house payment>car and house Insurance ,taxes etc. The working on airplanes ,Annuals, Prebuys, Weigh and Balance, Rigging and Battery's payments go into MY AIRPLANE account for Insurance-Fuel,Hanger >parts and everything else connected to my airplane habit.I spent a considerable amount on tools,drawings and parts just on My Firewall Mounted battery and If I sell 1-2 or more a month that's good. I went for a STC/PMA for 2 years at a cost of over $17,000.oo USD -and still didn't get my STC .I pretty well connected at FAA MIDO/FSDO and they just told me they would approve my Install per a 337 and Field approval so that's where were at. The 337's I issue with a kit will put you on the fast track to approval > That's how it is if you want to BUY my Firewall Battery Kit it comes with everything including the approved example that has worked in over 100 airplanes world wide.I had Many request "let me take this to FAA and see if I can get this approve" I won't send it out to customer --- I will send direct to FSDO Inspector office and tell you want to mod your airplane. I would be glad to sell individual parts as necessary but not give them away. If you want to contact me or my website for information that's ok. If you want a Burls box so be it -use his paperwork > If you want mine you'll have to buy it .

hotrod150 wrote:

Glidergeek wrote:So out of everybody out there that's encouraging get a F/A nobody has an example of one? Does that mean it hasn't been done? Or nobody's willing to share?

I have had the grand total of two, count 'em two, field approvals done. On both of them, the IA I was working with contacted his PMI (FAA inspector) and ran the proposed mod by him. After getting the go-ahead, we went ahead & did the work, wrote it up, and got it signed off. So IMHO it is critical to have a good IA to work with, and also critical that he be on good terms with his PMI & that they both have experience and/or are comfortable with doing field approval mods.

2? and were these done on the SBS J16 battery mounted on the firewall in a bracket or fabed box?

Some interesting reading on pages 107 thru 122 of the link below.

http://rgl.faa.gov/Regulatory_and_Guida ... _13-2B.pdf

And in this forum on the Skywagon Forums if you scroll down about 7 threads there is discussion that a F/A was not needed for this installation citing the above circular.

http://www.skywagons.org/forum/showflat ... #Post10632

Glidergeek wrote:

hotrod150 wrote: I have had the grand total of two, count 'em two, field approvals done.......

2? and were these done on the SBS J16 battery mounted on the firewall in a bracket or fabed box?

One was for installing the SBS J16 battery in the existing battery box, the other was for a single (185) rear seat in my C170.

bushwagon wrote:
I bought the Burl's mount for $115 direct from them ..........

Pretty hard to beat an STC complete with the mount for $115. There's a guy who has quite a few STC's for Pacers, pretty simple stuff like bigger tires, borer prop, etc, and I think he gets $250 each just for the paperwork. Worth it if you wanna do them mods & stay legal -- believe it or not, not everyone does the paperwork required
But at $250 a crack, they do add up after a while.

It's $225 for Burl's now gotta buy the mandatory heat shield, still a good deal. But from my last post could possibly be considered a minor alteration only requiring a log entry and maybe a 337 at the most. Any A&P's out there got an interp?

Anyone care to comment about the issue of build quality and ease of installation between the STC version and 182STOL's field approval version?

Here's a great example... the Gill 35 standard garden variety airplane battery has been certified for a long time. The sealed lead-acid batteries (first called Gates, then Hawker, now Odyssey) is a far better, safer battery by comparison but it was not certified for a long time. The Gill was cheaper and it was certified. The sealed battery was more expensive and needed a field approval but it is a better battery.

Most everyone who has flown with the sealed battery is happy they spent the extra money to buy it. Anyone here think that this frightening concept could also apply to the battery box?

EZFlap wrote:Anyone care to comment about the issue of build quality and ease of installation between the STC version and 182STOL's field approval version?

Sure, I can provide some info on the Burl's battery box. It appears to be made of high quality material. The workmanship is excellent. As far as ease of installation, it was probably one of the easiest mods I have done on my aircraft. I too have the heat shield with my box. It is simple to remove with 2 supplied wing nuts and provides for easy remove of the battery if needed. I am extreemly impressed with the cranking power of the Odyssey paired with my new Skytech starter. For me the STC was the easiest way to go. I'm being told the approval process through the Denver FSDO is averaging around 3 months.

EVERYthing Burl Rogers builds and sells is top quality, well thought out, and is backed up by Burl. He's a stand up guy, and a great craftsman.

MTV

Glidergeek wrote:It's $225 for Burl's now gotta buy the mandatory heat shield, still a good deal. But from my last post could possibly be considered a minor alteration only requiring a log entry and maybe a 337 at the most. Any A&P's out there got an interp?

FAR part 43, apendix A addresses major alterations. Also AC43-13 has guidelines for work performed.
Reading part 43 app A it doesn't seem to me that relocating a battery is a major alteration. But using an Odyssey type battery, even (as I did) the PMA'd one that's approved for PA18's, is not in accordance with the Cessna TCDS & so maybe does require specific approval.
The whole 337/field approval thing seems like a gray area to me. I've seen plenty of radio's installed with just a logbook entry. Yet when I replaced the com radio in my airplane, my A&P talked to his PMI & was told that a 337 was required, and if the radio was not TSO'd, a field approval would also be required.
I guess it all boils down to however your A&P/IA feels comfortable handling it-- if he just logs it & signs it off, great-- but if & when another A&P/IA gets involved with the airplane a few years down the road, it may be that he won't be satisfied & will want a 337 etc. My thought is when in doubt, do some paperwork & CYA.

So an aircraft will stall slower, and cruise faster with an aft CG. An aircraft will stall slower and usually cruise faster with less weight. The placement of the smaller battery into a forward location removes weight but moves the CG forward. While I fully appreciate the benefit of this mod when operating the aircraft loaded I think many fly one or two up front and don't see the benefit to flight characteristics.
So my question for the engineers out there: If there is a 20# weight reduction, but we've moved the CG forward by so much, all other things neutral (you aren't loading your gear in the way back, like we would all do) - is this a neutral change to the flight characteristics. Does the benefit of the weight reduction cancel out the downside of forward CG. Anybody with a fancy calculator?

Matt 7GCBC wrote:So an aircraft will stall slower, and cruise faster with an aft CG. An aircraft will stall slower and usually cruise faster with less weight. The placement of the smaller battery into a forward location removes weight but moves the CG forward. While I fully appreciate the benefit of this mod when operating the aircraft loaded I think many fly one or two up front and don't see the benefit to flight characteristics.
So my question for the engineers out there: If there is a 20# weight reduction, but we've moved the CG forward by so much, all other things neutral (you aren't loading your gear in the way back, like we would all do) - is this a neutral change to the flight characteristics. Does the benefit of the weight reduction cancel out the downside of forward CG. Anybody with a fancy calculator?

try this

http://home.roadrunner.com/~trumpetb/alph/wb180.html

Glidergeek wrote:My dilemma is with the Pponk Super Eagle mod I'm doing it's supposed to add 45-50 lbs. that's all up front. I'm changing to the Lite wt. starter and the alternator loosing about 16 lbs with the 2. If I do the battery on the firewall I'll loose an additional what 20-25 lbs? With a net gain of 10-15 lbs but with a even more forward CG. Will 10 lbs in the tail counter the forward CG? And if you answer this today why aren't you out flyin, I've got an excuse

Not sure this got answered for you. Shorfielder has a 180 with a p-ponk and he has the Burl fire wall mounted battery. He just loves it. Send him a PM about it. I have his cell phone # that I would give you if you want. Send me a PM if interested in that.

I put a Burl box on my current 182B. I put an early version 182 Stol box in my previous 182B. Both good boxes. I have seen Bill's latest version and it looks real good. As far as the boxes themselves are concerned, I see no advantage of one over the other. Bill is a good guy IMHO. But then again, some think I am not.

Tim