Concorde battery installation

[kevinw]

I don't mean to beat a dead horse. This has been discussed but I'm getting some conflicting information. I plan to replace my Gill G-35 battery soon with a Concorde; either the RG-35A or RG-35AXC. It's my understanding if I stick with the RG-35A I can do it myself, make a logbook entry and I'm done. If I go with the RG-35AXC, I'll need an STC, have the weight and balance updated due to the extra five pounds of weight and also have AP sign off on it. If that's the case I would go with the RG-35A, not lose any useful load and be done with it. Can someone tell me for sure? It's going in a 1982 M20J.

 

http://www.concordebattery.com/aag3.php?id=2268

 

[orionflt]

Concord holds a certificate allowing direct replacement without having to do STC paperwork for your aircraft. it is now just a logbook entry.

 

Brian

[Bob_Belville]

The weight difference is a couple of pounds, probably worth the difference in cranking power.

 

I just installed a XC in my M20E. The W/B had been done several years ago for a prior installation. I do not believe a STC but I am not an A&P so do not take my opinion as definitive.

 

Best price I found on a Concorde RG-35AXC battery was Chief Aircraft: $272.50, free freight.

[kevinw]

The weight difference is a couple of pounds, probably worth the difference in cranking power.

 

I just installed a XC in my M20E. The W/B had been done several years ago for a prior installation. I do not believe a STC but I am not an A&P so do not take my opinion as definitive.

 

Best price I found on a Concorde RG-35AXC battery was Chief Aircraft: $272.50, free freight.

Did you install it yourself without any W&B change?

[Bob_Belville]

Did you install it yourself without any W&B change?

I installed it and logged it with my name and PPL#. But the W&B already reflected the heavier battery from a previous "upgrade". If I had been replacing a lighter battery I would have updated the W&B and had my A&P sign off on it. 

[DonMuncy]

Is it everybody's opinion that an owner can change the battery and can do the weight & balance change, but an A&P has to sign off on it. Maybe the FAA thinks an owner is not to be trusted with higher mathematics, like multiplication.

[laytonl]

Y'all are too fussy about rules. Lee

[Hank]

I don't remember how mine was done, it was during annual in 2010. Still going strong at my annual in January, 4 years and a bit, still turning over fast enough to taxi the plane.

[jetdriven]

The weight difference is a couple of pounds, probably worth the difference in cranking power.

I just installed a XC in my M20E. The W/B had been done several years ago for a prior installation. I do not believe a STC but I am not an A&P so do not take my opinion as definitive.

Best price I found on a Concorde RG-35AXC battery was Chief Aircraft: $272.50, free freight.

It's not cranking power, it's reserve in minutes after your alternator quits. Especially important for a plane flown in IMC.

The other day I was giving a prospective 201 buyer a checkout in my plane. Halfway through, the alternator quit. We finished the stalls and went back for 5 or 6 landings. That took about 30-40 minutes. Then taxied to the hangar and there was enough reserve capacity to start the engine twice more after it sat a week. That's the benefit of an RG35-AXC

[47U]

As the FAR says... “Major alteration means an alteration not listed in the aircraft, aircraft engine, or propeller specifications—

(1) That might appreciably affect weight, balance, structural strength, performance, powerplant operation, flight characteristics, or other qualities affecting airworthiness;"

Sure, it's only a couple of pounds, but it's back towards the tail where the arm is a lot longer than us with the battery on the firewall. So, not only do you have a weight increase of a couple pounds, it's also going to move your CG aft.

What kind of terms are you on with your IA? The 337 is pretty simple to fill out, so why not just do it? If, on your next annual, your A&P/IA notices the battery and looks in the logbooks for the weight and balance change and doesn't find it, will they wonder what other mischief the hangar faries have been up to? It would be awkward if they decided to not sign the annual until the 337 was accomplished. Why put yourself in that situation?

[Andy95W]

As the FAR says... “Major alteration means an alteration not listed in the aircraft, aircraft engine, or propeller specifications—

(1) That might appreciably affect weight, balance, structural strength, performance, powerplant operation, flight characteristics, or other qualities affecting airworthiness;"

Sure, it's only a couple of pounds, but it's back towards the tail where the arm is a lot longer than us with the battery on the firewall. So, not only do you have a weight increase of a couple pounds, it's also going to move your CG aft.

Respectfully disagree. Key word is "appreciably". Even as much as 5 pounds toward the tail is a minor shift in CG, for a 2000+ pound airplane.

Y'all are too fussy about rules. Lee

Oh, yeah.

I installed it and logged it with my name and PPL#. But the W&B already reflected the heavier battery from a previous "upgrade". If I had been replacing a lighter battery I would have updated the W&B and had my A&P sign off on it.

Exactly correct, in my humble A&P/IA opinion. Though I've been wrong in the past.

[N601RX]

The axc is PMA approved for most models. No 337 is needed.

[47U]

The Concorde installation instructions say to update the weight and balance, if required... PMA or not. My switch from to the Concorde was a 5 lb increase which I interpreted as "appreciable" even though my battery is on the firewall. As always, though, YMMV.

[cliffy]

Any change of more than 1 (one) pound requires a W&B computation done by an A&P.

[cliffy]

Forgot to add

An owner/PP can do the battery change AND sign it off per regulation but if it requires a W&B change of more than 1 pound an A&P must do the W&B paper work. Yes, the Feds don't think pilots can add and subtract.

[Hank]

Forgot to addAn owner/PP can do the battery change AND sign it off per regulation but if it requires a W&B change of more than 1 pound an A&P must do the W&B paper work. Yes, the Feds don't think pilots can add and subtract.

Oh, we can plus and minus pretty well, it's that plutification is so haaaarrd!!

[carusoam]

Reference points...

1) The POH for the O uses 1/10ths of a pound regarding equipment added/subtracted from the plane.

2) Engineers are trained to perform W&B calculations, early on, in a class called 'Statics'.

To keep the trim system working as designed/calibrated it is best to keep the center of gravity cg from changing. This is done using the W&B calculation.

[Hank]

Reference points...

1) The POH for the O uses 1/10ths of a pound regarding equipment added/subtracted from the plane.

2) Engineers are trained to perform W&B calculations, early on, in a class called 'Statics'.

To keep the trim system working as designed/calibrated it is best to keep the center of gravity cg from changing. This is done using the W&B calculation.

Phun with physics!

-a-

Oh the joy!! Statics! Followed by Dynamics 1 & 2 (this is where poor W&B will bite you) and Dynamics of Machines. Lycoming apparently paid attention to this last one, as my engine runs smoothly. Ditto for whoever did the propeller balancing for the previous owner.

Just a few of the fun classes that made sure I knew all 300+ functions on the world's largest calculator.

[211º]

Looks like adding 5 lbs for the extra crank battery at Sta 160+/- moves the CG backwards about 0.25 inches.

[Hank]

3 hours ago, 211º said:

Looks like adding 5 lbs for the extra crank battery at Sta 160+/- moves the CG backwards about 0.25 inches.

Lucky you! Mine's on the front of the firewall. AND I have a heavy, metal Hartzell 3-blade prop.

Speaking of which, it's time to think about a new one. This one was installed in Dec 2010 (A&P wrote it on top in black marker), and I've not flown much in the last year, lots of sitting in the hangar in the heat. She's turning over slow, but still cranks reliably, even in hot starts, but I used to could taxi with the starter . . .