Full workup of Weight and Balance

[gitmo234]

I have a 1956 C172 that was produced before a lot of standard paperwork (by todays standards) was done. That includes the standard POH type writeup (outside the owners manual).

So from then I have work ups done since installation of avionics equipment and other work. I am wondering now, how difficult it would be to get a legitimate weight and balance work up done, and how much it would cost?

is that even feasible?

 

[RotorAndWing]

I have a 1956 C172 that was produced before a lot of standard paperwork (by todays standards) was done. That includes the standard POH type writeup (outside the owners manual).

So from then I have work ups done since installation of avionics equipment and other work. I am wondering now, how difficult it would be to get a legitimate weight and balance work up done, and how much it would cost?

is that even feasible?

May cost $20, may cost $2000.

It's feasible, very easy to accomplish. But with only two paragraphs of vague information on an internet forum, you are not going to get an accurate answer.

If you own an airplane, I would think you have a mechanic that does the annual inspection. Why not just ask him?

 

[gitmo234]

Havent owned it long enough to require an annual and its a sunday night and I just thought of it now.

He's replacing the spinner dome tomorrow so I'll probably give him a call tomorrow (now that I know the basic range of it)

 

[RotorAndWing]

Havent owned it long enough to require an annual and its a sunday night and I just thought of it now.

He's replacing the spinner dome tomorrow so I'll probably give him a call tomorrow (now that I know the basic range of it)

Sure, lay it out in front of him and get his opinion. You may be pleasantly surprised.

 

[Silvaire]

If what you are looking for is a complete equipment list with accurate weight and arm data I think that would be extremely difficult to accomplish because you really don't have any base to start with and any data you do have would have to be verified.

Probably the best thing to do is just weigh it and start with a clean sheet.

 

[gitmo234]

Spoke to him today and we went through all the available docs back to about 1972. He hs all the equipment to a new weight and balance with a new equipment list. Since I'm getting the spinner some replaced he's just gonna do that at no charge immediately after. He's also going to organize the AD list a bit better.

I have to say that I'm liking my experience with the shop at 58M.

 

[gitmo234]

Should also note that I have all the docs and books dating back to 1957, but there isn't much to go by until 74. There's a lot more logging and annotation of equipment changes, etc since then

 

[mrkbbd]

All you have to do is weigh it on the three wheels and it's easy to figure out CGs and everything, just a little math and measuring

 

[ja_user]

You could just weigh it, but be warned.. It doesn't get lighter with age...

 

[LDJones]

All you have to do is weigh it on the three wheels and it's easy to figure out CGs and everything, just a little math and measuring

The odds of the adds/deletes ultimately being right would be fairly slim, especially since you've indicated early records are a bit thin on details. Just weigh it and know exactly where you stand as configured today.

 

[Tom-D]

Your A&P-IA should have an accurate equipment list to do their AD research prior to the annual, it takes about 30 minutes to weigh the aircraft, and get the three numbers you need, then another 30 to compute the new CG and empty weight.

I do the whole chore for $150.00

 

[Tom-D]

You could just weigh it, but be warned.. It doesn't get lighter with age...

Many times they do get lighter when the owner dumps the 2 Mark 12s the ADF, the DME, all the associated wires, co-axe, and antennas and only replace them with 1 GPS, plus dumping the old nauga interior, and replace with a light weight wool and leather it will really lighten the load.

 

[Silvaire]

Like I said in my first post if all you want is a document then you can cobble one together from the data and log entries you have but you don't know the accuracy of that data without physically weighing and measuring each item listed. Honestly, the only real use of an accurate and detailed equipment list like that (in regards to weight and arm) is to make it convenient to recalculate the W&B when an alteration is done.

From a realistic perspective it makes more sense to wipe the slate clean and just weigh the aircraft. That way you get the numbers that you really need. Any alteration then starts from a rebooted datum and is not carrying the baggage of an inherent error.

 

[Tom-D]

Like I said in my first post if all you want is a document then you can cobble one together from the data and log entries you have but you don't know the accuracy of that data without physically weighing and measuring each item listed. Honestly, the only real use of an accurate and detailed equipment list like that (in regards to weight and arm) is to make it convenient to recalculate the W&B when an alteration is done.

From a realistic perspective it makes more sense to wipe the slate clean and just weigh the aircraft. That way you get the numbers that you really need. Any alteration then starts from a rebooted datum and is not carrying the baggage of an inherent error.

You can just as easy make the mistake weighing the aircraft.
How much gas was aboard?
Was the pilots flight bag aboard?
How much tear weight was that?
Was the A/C really level?
Did the scales get zeroed?

Nothing is perfect.

 

[Silvaire]

You can just as easy make the mistake weighing the aircraft...

But you are in control and can just as easily find someone's prior error. You can't very well argue against weighing the aircraft just because you might make a mistake.

 

[Jimmy cooper]

But you are in control and can just as easily find someone's prior error. You can't very well argue against weighing the aircraft just because you might make a mistake.

Very true! Logical. Another place to look is paint......paint is heavy. If it's been repainted by light sanding instead of stripping it could add a good amount of weight.

 

[gitmo234]

I'll find out and report back. The spinner dome is supposed to be replaced "sometime this week", followed by it being weighed and all that stuff computed, new POH issued and a few other small things done all for the cost of the spinner dome being replaced.

 

[Tom-D]

Very true! Logical. Another place to look is paint......paint is heavy. If it's been repainted by light sanding instead of stripping it could add a good amount of weight.

Do you know the difference between the polished 172, and a painted one?

Factory numbers were 15 pounds.

 

[Tom-D]

But you are in control and can just as easily find someone's prior error. You can't very well argue against weighing the aircraft just because you might make a mistake.

Just making the note, be certain it's done right.

 

[bnt83]

This really isn't as big a deal as everyone makes it.

#1 Just weigh the airplane. Fuel drained and sumped is the best way. There is "headspace" in each fuel tank and aircraft weigh heavy when the fuel tanks are topped off vs weighing drained and sumped.

#2 You should be able to get the factory equipment list from Cessna. If not, ask around on the forums and hopefully someone with the same year airplane can give you a copy of theirs to use as a guide in making a new one for yourself.

(Equipment Lists in heavy private aircraft are typically a mess because often they don't have just one book that holds the ORIGINALS, so there are a few books containing both copies and originals and if one book gets updated the others may or may not. Its a huge PITA!!!!)

My advice to all customers, is keep the originals in a binder with logbooks. Keep copies of them in the airplane.

Make a binder to keep things organized in the airplane. You can throw the originals on a copy machine to reduce the size to about 63% and they will fit into a half-sheet binder with no problem. That binder will fit in all the glove boxes I've tried.

In this case I bought a brand new 205 owners manual (from Cessna $40) and was pleasantly surprised to see the plastic spiral binding. I removed the binding, three-hole punched it then re-installed the binding. Now it can be added to the three ringed binder.

If you have FAA approved supplements, like an Aspen, I would try to get a pdf color copy from Aspen then print it two sided color on a laser printer at 63% to 67% size to fit this binder. I use at least 24# paper as 20# is just too cheap and not durable.











An example of trying to catch up the equipment list:

 

[gitmo234]

Brian,

thanks for the post. Very helpful. This all stems from buying the airplane, I got it low priced and was suspicious even though I had an intense pre-buy, and several disinterested parties look through logs, results etc.

Still had that feeling... There was no organization or just clean papers I could look at and get a clear answer. I have stacks of paperwork from 56 on to as soon as now, but no one thing seemed comprehensive.

Unrelated to the weight and balance, I got some of my answers (and its good news).

Getting an updated airworthiness certificate (mine is from '56 and pre-dates the FAA) since mine is laminated but tattered and torn.

I talked with the local mechanic and we sat down and went through every page of everything, and all the log books. I explained that I wanted things clean, concise and organized. All the required docs, I wanted an updated/current version, and needed to know what I should save, burn, etc from all the other stuff.

He's helping me out with it (including getting it weighed) but as part of all that digging the only thing we found is that my transponder needs to be tested. That is scheduled for Friday (while I'm meeting with my DPE, prior to scheduling a check ride).

So when that time comes I've got a handful of clean docs to show, I'm confident the airplane paperwork is in good order, and I dont have to dig and bungle through a stack of paperwork, explain some stuff wasnt done prior to certain years etc.

I'm not worried about the transponder test. I've used it on flight following and the controllers have consistently read back accurate altitude and squawks.

 

[bluerooster]

As far as "cleaning up" the documentation, I would not dispose of anything, but keep it in a folder somewhere. (I'm a packrat)
Over the years, our Cherokee 180 had undergone all kinds of removal/replacement/upgrades. All was properly documented, and new W&B calculated each time. When we first got it, it had a single kx155/vor/loc. and a transponder, that was it. We "upgraded" to a kma24, gns300 with indicator, and mk12d with G/S, and indicator. In the process there was a bunch of old wiring, and antennae removed that no longer went to anything. When finished, we decided to weigh the airplane and re-calculate the W&B. We lost several pounds.