Weight gain over years

[Ignacio Allende]

It seems every weight & balance from factory can seldom be kept up in time. But interiors are getting lighter, as well as avionics and instruments. Even if the plane has damage history it had to be repaired with the same parts, no add-ons.

Surely adding extra equipment to the original list will make its toll, but not reasonable ones it seems. In my case I am carrying about 350 misterious-pounds. Many (most?) people have the same issue in scale to what they own. Can't be gathered dust, can it?

 

[Salty]

Every plane I've ever seen weighed has gone up, and usually significantly. It's to the point where I think the factories were fudging their numbers.

 

[JAWS]

That is one reason why scales need to be calibrated. Then they need to be used correctly. Then the aircraft has to be configured and leveled properly. Then the person doing all this needs to keep the numbers in line.

Many variables that can lead to many different outcomes (ie: a bit heavier, a lot heavier, cg fwd, cg aft, etc). Even the ceiling fans or open hangar door can affect the end result.

Make sure the mm and tcds are followed for configuration and arms.

 

[MooneyDriver78]

I put the 100 w&b changes made to my plane into a spreadsheet to check the math, found numerous mistakes: simple math errors, transposed digits, etc. In the end, it was a 1-2 lb difference.
APs don’t empty the fuel tanks, they either use the horrible inaccurate fuel gauges, or fill the tanks and use the stated fuel capacity.


Tom

 

[MBDiagMan]

My Cessna 140 has peaked out and now headed the other way. In about 1980 it got an O200A with a vacuum pump, alternator and at the same time got a custom IFR panel with lots of heavy NAV’s and COM’s and a remote compass. Just before I got it, an oil filter was added to the mix.

A few weeks ago she got a fresh O200 and got a lightweight starter in the conversion. Not long before that it got a slightly lighter transponder. As more time goes by, I expect the radios will be updated causing more dietary loss.

 

[Dan Thomas]

Every plane I've ever seen weighed has gone up, and usually significantly. It's to the point where I think the factories were fudging their numbers.

Yup. I've seen that.

We bought a 2006 Cessna 172SP. Its weight and balance was a "fleet" W&B, in their terminology. They must have weighed a few airplanes and averaged the numbers. I did an actual and found that it was off by eight or 10 pounds. And I used calibrated and certified electronic scales.

 

[Dan Thomas]

It seems every weight & balance from factory can seldom be kept up in time. But interiors are getting lighter, as well as avionics and instruments. Even if the plane has damage history it had to be repaired with the same parts, no add-ons.

Surely adding extra equipment to the original list will make its toll, but not reasonable ones it seems. In my case I am carrying about 350 misterious-pounds. Many (most?) people have the same issue in scale to what they own. Can't be gathered dust, can it?

Damage repairs usually make an airplane heavier. Patching cracks, adding doublers, more primer and paint--it all adds up. Dirt in the belly adds up. But the biggest source of extra weight is often errors in the arithmetic on W&B amendments. I've found stuff removed and its weight added instead of subtracted. Found the arms all confused (i.e. behind instead of ahead of the datum) so that the CG is way off. I once came across a Taylorcraft that had, according to the W&B paperwork, a 120-pound useful load. That 120 pounds had to cover the fuel and occupants and baggage. It meant that there was an error of around 400 pounds somewhere, and there was no way that an 800-pound airplane had gained 400 pounds.

Sometimes one simply has to do an actual weighing. Start all over again.

 

[Ignacio Allende]

Every plane I've ever seen weighed has gone up, and usually significantly. It's to the point where I think the factories were fudging their numbers.

But it doesn´t seem to stop after that first out-of-factory real W&B. If they averaged airframes and/or fudged their numbers then it reflected immediately on the next w&b. But we seem to have a continuous increase (like my belly) here. Two or ten pounds here and there... but that's not the case to almost every owner if they crosscheck their actual weight against delivery or first ones done. It makes me real wonder...

Damage repairs usually make an airplane heavier. Patching cracks, adding doublers, more primer and paint--it all adds up. Dirt in the belly adds up. But the biggest source of extra weight is often errors in the arithmetic on W&B amendments. I've found stuff removed and its weight added instead of subtracted. Found the arms all confused (i.e. behind instead of ahead of the datum) so that the CG is way off. I once came across a Taylorcraft that had, according to the W&B paperwork, a 120-pound useful load. That 120 pounds had to cover the fuel and occupants and baggage. It meant that there was an error of around 400 pounds somewhere, and there was no way that an 800-pound airplane had gained 400 pounds.
Sometimes one simply has to do an actual weighing. Start all over again.

That's interesting. I was told that in my case (my plane had wing damage) the exact same parts were replaced so I can't justify such a gross increase, but I'd have to visually check for doubles really.

What are your increase numbers over time?

 

[Caramon13]

It seems every weight & balance from factory can seldom be kept up in time. But interiors are getting lighter, as well as avionics and instruments. Even if the plane has damage history it had to be repaired with the same parts, no add-ons.

Surely adding extra equipment to the original list will make its toll, but not reasonable ones it seems. In my case I am carrying about 350 misterious-pounds. Many (most?) people have the same issue in scale to what they own. Can't be gathered dust, can it?

Is the plane eating things when you aren't looking? Is it being exercised? All that leaded fuel goes straight to the belly..

 

[Challenged]

I just gained 31 lbs of useful by replacing the entire panel. Unfortunately the only way I can make use of it in the Bonanza would be to shove my suitcases under the engine cowling. However, I also gained over 30 lbs of useful when I weighed the Beech Sierra I owned after purchase, so it is possible to go the other way sometimes.

 

[cgrab]

I go to the VA twice a year for checkups and my doctor has all my records since 1975. She frequently pulls up my weight history and tells me I weighed 110 when I joined the Navy and at one point I was 215. She is happy now that I'm hovering around 190.

 

[Kenny Phillips]

It seems every weight & balance from factory can seldom be kept up in time. But interiors are getting lighter, as well as avionics and instruments. Even if the plane has damage history it had to be repaired with the same parts, no add-ons.

Surely adding extra equipment to the original list will make its toll, but not reasonable ones it seems. In my case I am carrying about 350 misterious-pounds. Many (most?) people have the same issue in scale to what they own. Can't be gathered dust, can it?

Interiors are not getting lighter, in my opinion. The 27 G requirement on new seats certainly made them heavier than the featherweights in my '65 Skyhawk. Leather is heavier than cloth. Sound deadening is heavy. (And ... manufacturers lied in the past.)

 

[Timbeck2]

Cherokee 140 empty weight from the factory as listed on the brochure on my plane is 1,213 lbs.
As weighed empty about 4 months ago - my plane weighed 1,368 lbs and this was AFTER I removed the vacuum system, replaced the AI and DG with Garmin G5s, replaced the alternator and starter with light-weight Plane Power components. I also replaced my cloth interior with leather and the side panels were actually lighter than the original. My plane is clean inside and out so I have no idea how my plane could GAIN 155 lbs. A friend of mine did similar things to his 210 and his plane gained weight as well using the same scales. He is having his weighed again somewhere else as we think the scales were the culprit.

 

[asicer]

Cherokee 140 empty weight from the factory as listed on the brochure on my plane is 1,213 lbs.
As weighed empty about 4 months ago - my plane weighed 1,368 lbs and this was AFTER I removed the vacuum system, replaced the AI and DG with Garmin G5s, replaced the alternator and starter with light-weight Plane Power components. I also replaced my cloth interior with leather and the side panels were actually lighter than the original. My plane is clean inside and out so I have no idea how my plane could GAIN 155 lbs. A friend of mine did similar things to his 210 and his plane gained weight as well using the same scales. He is having his weighed again somewhere else as we think the scales were the culprit.

Does your A&P let you stand on the scale before the plane goes on it? Maybe a way to get a feel for how accurate they are.

 

[Timbeck2]

Hindsight being 20/20 and all, no but there wasn't any reason to doubt calibrated scales beforehand.

 

[Ignacio Allende]

Cherokee 140 empty weight from the factory as listed on the brochure on my plane is 1,213 lbs.
As weighed empty about 4 months ago - my plane weighed 1,368 lbs and this was AFTER I removed the vacuum system, replaced the AI and DG with Garmin G5s, replaced the alternator and starter with light-weight Plane Power components. I also replaced my cloth interior with leather and the side panels were actually lighter than the original. My plane is clean inside and out so I have no idea how my plane could GAIN 155 lbs. A friend of mine did similar things to his 210 and his plane gained weight as well using the same scales. He is having his weighed again somewhere else as we think the scales were the culprit.

This is what I'm talking about. Will be very interesting to know how your friend's new w&b goes. Anyway as far as I've seen the scales always errs up, never down.

Does your A&P let you stand on the scale before the plane goes on it? Maybe a way to get a feel for how accurate they are.

That's a good idea, now that I'll always be suspicious about airplane scales.

 

[asicer]

That's a good idea, now that I'll always be suspicious about airplane scales.

Alternate plan would be to bring a gallon of water and see if it weighs 8 pounds. Or 5 gallons and 40 pounds.

 

[Dan Thomas]

Alternate plan would be to bring a gallon of water and see if it weighs 8 pounds. Or 5 gallons and 40 pounds.

Don't forget the weight of the pail...

 

[asicer]

Don't forget the weight of the pail...

Well if it weighed 8lbs/gallon with the pail then I wouldn't be too unhappy about putting the plane on the scale. It's the other direction that's more concerning.

That is, unless it was a 5lb pail.

 

[Huckster79]

You can find weight to lose. I’m at about 50 lbs I’ve taken out of my Cessna 140. It’s last w&b was a 2016 reweigh. I will do one once done...

Second landing light 6lbs
Child’s seat 6lbs
Lightweight battery 16lbs
Full interior strip and extra goodies along the way like the antenna wire for the loran, etc guesstimate around 20lbs.

Going to get seats done cushions are old heavy horse hair filled ones- the new foams will be lighter, idk how much.

But look around close and you may find ways without breaking the bank to lighten her up.

Worse part of mine is with going naked interior someone plastered a glue on the inside of the skin, to hold fiberglass insulation- been getting that crap off her for 4 long nights, 90% of the way cleaned up after tonight. I’m going to leave it naked, though painted... will still be lighter than all that old upholstery.