new battery and w&b

drgwentzel

drgwentzel

Pre-takeoff checklist
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Kobra
Flyers and mechanics:

I had enough of the Gill batteries and went with the Concorde battery because the word through the grape vine was that they were sealed, stronger and had better, longer life, all other things being equal.

I noticed that the Gill battery is about 27 lbs. and the Concorde is 32 lbs. On my plane (1971 C177RG, Cessna Cardinal RG) the battery is behind the rear bulkhead in the tail cone. Since it is 5 lbs. heavier, I would think I needed a recalculated w&b. I assume that I can't officially do that, so shouldn't my IA do that or is 5 lbs. so small that it's insignificant? I asked my IA and he said, "I'll have to think about it." What say the group?

Gene
 
Why not calculate the difference and have your A&P sign it off?
 
drgwentzel said:
Flyers and mechanics:

I had enough of the Gill batteries and went with the Concorde battery because the word through the grape vine was that they were sealed, stronger and had better, longer life, all other things being equal.

I noticed that the Gill battery is about 27 lbs. and the Concorde is 32 lbs. On my plane (1971 C177RG, Cessna Cardinal RG) the battery is behind the rear bulkhead in the tail cone. Since it is 5 lbs. heavier, I would think I needed a recalculated w&b. I assume that I can't officially do that, so shouldn't my IA do that or is 5 lbs. so small that it's insignificant? I asked my IA and he said, "I'll have to think about it." What say the group?

Gene
Click to expand...

Did the battery come with a STC? Many mechanics consider anything over one pound as the cut off for a W&B entry. An A&P has to sign off a change to the aircraft W&B documentation.
 
drgwentzel said:
Flyers and mechanics:

I had enough of the Gill batteries and went with the Concorde battery because the word through the grape vine was that they were sealed, stronger and had better, longer life, all other things being equal.

I noticed that the Gill battery is about 27 lbs. and the Concorde is 32 lbs. On my plane (1971 C177RG, Cessna Cardinal RG) the battery is behind the rear bulkhead in the tail cone. Since it is 5 lbs. heavier, I would think I needed a recalculated w&b. I assume that I can't officially do that, so shouldn't my IA do that or is 5 lbs. so small that it's insignificant? I asked my IA and he said, "I'll have to think about it." What say the group?

Gene
Click to expand...
Did you weigh both batteries or just use the manufacturer's data?
 
Your IA has to think about this? Odd. He needs to do the W & B.
 
drgwentzel said:
Just the Manufacturer's data was used. Not good?


Gene :dunno:
Click to expand...
From what I've read, the specified weight of a properly filled and charged (the weight does vary with the charge) Gill vented battery is often a pound or two higher than what their data shows and the sealed Concords generally come in under the "manufacturer's suggested" weight.

I'd weigh the old one after charging it overnight and filling the cells and do the same with the new one (sans filling) then adjust the aircraft W&B accordingly. No sense throwing away a couple pounds of useful load.
 
gismo said:
I'd weigh the old one after charging it overnight and filling the cells and do the same with the new one (sans filling) then adjust the aircraft W&B accordingly. No sense throwing away a couple pounds of useful load.
Click to expand...
I would suggest that instead, you check your equipment list for the weight used there for the old battery, and compare the new one to that. Weighing the old battery will only tell you if the old w&b data inaccurately reflected the actual weight of the old battery, not what the plane is going to weigh after the battery swap.
 
Yes anything under 1 pund is considered negligible. Over 1 pound you update the W&B.

I don't understand why your AI would want to think about it. That will take longer than just updating the W&B.

When I switched from Gill to Concorde I did the W&B change myself and handed it to the AI while he was filling out the log book. It took all of 2 minutes.
 
Ron Levy said:
I would suggest that instead, you check your equipment list for the weight used there for the old battery, and compare the new one to that. Weighing the old battery will only tell you if the old w&b data inaccurately reflected the actual weight of the old battery, not what the plane is going to weigh after the battery swap.
Click to expand...
I agree and wish I'd suggested that.
 
Tom-D said:
Do you have a reference for that ?
Click to expand...

Yep:


AC 2043.13-1B

Section 10.1

c. Negligible Weight Change​
​
is any
change of one pound or less for aircraft whose​

weight empty is less than 5,000 pounds;
 
gismo said:
I agree and wish I'd suggested that.
Click to expand...
Simply read the AC 43-13,2B

1021. WEIGHT AND BALANCE. After installation or alteration with the replacement battery the weight and balance of the aircraft should be recomputed if:
a. The weight of the replacement battery is different from that of the original battery.
b. The location of the battery is different from that of the original battery.
NOTE: Weight and balance procedures for aircraft are contained in AC 43.13-1 (as amended), chapter 10.

it doesn't say any thing about how much the change will trigger the new W&B.
 
COFlyBoy said:
Yep:


AC 2043.13-1B

Section 10.1

c. Negligible Weight Change​
​
is any
change of one pound or less for aircraft whose​

weight empty is less than 5,000 pounds;
Click to expand...


didn't you make an alteration? changing from one battery to a different type of a different weight?

the AC 43,13-2B takes precedence (chapter 10.)
 
Tom-D said:
Simply read the AC 43-13,2B

1021. WEIGHT AND BALANCE. After installation or alteration with the replacement battery the weight and balance of the aircraft should be recomputed if:
a. The weight of the replacement battery is different from that of the original battery.
b. The location of the battery is different from that of the original battery.
NOTE: Weight and balance procedures for aircraft are contained in AC 43.13-1 (as amended), chapter 10.

it doesn't say any thing about how much the change will trigger the new W&B.
Click to expand...

Apparently any weight change would trigger new W&B calculation in this case.

PPC1052 said:
Your IA has to think about this? Odd. He needs to do the W & B.
Click to expand...
Mabe he wants to consult AC43.13 to be certian that W&B calc. is warrented? I dunno, but....
 
Last edited:
bluerooster said:
Apparently any weight change would trigger new W&B calculation in this case.
Click to expand...
It says "should" doesn't make it mandatory.

What would?? the STC installation instructions.
 
Tom-D said:
It says "should" doesn't make it mandatory.

What would?? the STC installation instructions.
Click to expand...

AH!, IC ;)

I'd probably do it anyway, but then I'm kinda anal about accurate records.

Depending on the age of the airplane, and how long it's been since it's been on the scales, and what's been done in the interim, I'd probably even weigh it. :eek:

I did that on our Cherokee 180, after an extensive avionix renovation. And found that we gained about 100 pounds of useful load. But this airplane had not been on the scales since 1963 when it was new. :rolleyes:
 
Did you check with Obama for this battery change? If not you are in real trouble and your plane is grounded.:eek:
 
bluerooster said:
AH!, IC ;)

I'd probably do it anyway, but then I'm kinda anal about accurate records.

Depending on the age of the airplane, and how long it's been since it's been on the scales, and what's been done in the interim, I'd probably even weigh it. :eek:

I did that on our Cherokee 180, after an extensive avionix renovation. And found that we gained about 100 pounds of useful load. But this airplane had not been on the scales since 1963 when it was new. :rolleyes:
Click to expand...

Odds are I wasn't even on scales in '63...
 
Skylane81E said:
Odds are I wasn't even on scales in '63...
Click to expand...
Good point. :)

But I found it interesting, that after removing 1 kx155, and installing a GNC300 with indicator, MK12D with indicator, KMA24, intercom, and king transponder, I actually lost weight.
and gained 100# useful load. :D
 
bluerooster said:
Good point. :)

But I found it interesting, that after removing 1 kx155, and installing a GNC300 with indicator, MK12D with indicator, KMA24, intercom, and king transponder, I actually lost weight.
and gained 100# useful load. :D
Click to expand...

Does that mean that the old W&B was wrong or the new one is?
 
Tom-D said:
Does that mean that the old W&B was wrong or the new one is?
Click to expand...

Methinks that your joke filter is suboptimal. It could probably be recalibrated at the pub of your choice, though. At no cost to you.
 
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