Charlie weight vs standard load??

[Marc_B]

I’m having some work done and noticed I have a weight in the tail. My POH (or any W&B sheet in my POH) doesn’t document that I had Charlie weights installed although the standard pOH does include the various Charlie weights and weights for all optional equipment.
is this an extra weight that I could remove if I see fit or is this a standard part of loadout?

(and pay no attention to loose washer, etc. work currently in progress…)

[KSMooniac]

Which model?

I don't have any on my J, but have thought about adding one or two. Generally, aft CG (within appropriate range of course!) increases speed. Adding weight decreases it...but adding a little way back in the tail is the most efficient way to move the CG aft, as opposed to adding some in the baggage compartment.

Many/most mid and long body Mooneys could benefit from moving the CG aft a bit, unless frequently flying with full back seats and/or baggage. Engines got bigger and heavier, turbos got added, heavy 3 blade props got popular, etc, and CGs moved forward. Long bodies got a second battery installed way back in the tail to counter some of that. I think on something like a Rocket you can go out the front of the range with just front seats occupied as an example...

I'd suggest getting your W&B current and see the effects of the weight for your plane, then decide to keep or remove.

Sent from my LM-V450 using Tapatalk

[Marc_B]

@KSMooniac M20K Encore.  Here's the page from my POH.  I don't have anything marked as installed.  Don't see any mention in logs.  But this is a charlie weight right?

[carusoam]

hmmmmm….. that’s a puzzling question…
 

Mark,

Is that your original POH that came with your specific plane?
 

The WnB charts of the M20R look very similar… and include number and weight of the Charlie weights that are installed…

The Long Bodies are designed with a bit of flexibility…

The options included Fiki, AC, O2, and Lead blocks…

 

So…. Yes you have a Charlie weight. As many Mooneys do… including the short bodies…. Often hidden on a back shelf near the tail hinge…

If you are redoing your WnB calculations… and the tail is heavy… the extra Charlie weight can probably be removed…

 

Expect that there is still an engineering group/person at the Mooney factory that you can ask this question to… (?)

If going this way… expect to supply a lot of data…  see if you can find the part number on the CW itself…

 

Most Mooneys have lost a bunch of weight up front when their old analog boxes get removed and replaced with digital technology… Or an MT prop shows up on the nose….

Dig extra deep in your documents to see if the CW is in there somewhere… that empty section of optional CWs is a bit odd…. 

If it is really a CW… it doesn’t have anything structural about it…

If nothing else… check in with @M20Doc (M20K with an apparent undocumented Charlie weight (?))

Construction records at the factory probably include the CW in the as builts…. In the event the POH you have is not specific to your plane…

Mooney can provide a POH for your specific serial number, as it left the factory… (some work on their end is required…)

 

PP thoughts only, not a mechanic…

Best regards,

-a-

[kortopates]

See your Mooney service manual for very specific guidance on when and how much charlie weight should be added. You’ll find a graph that show when they’re required.
The addition of a previous charlie weight would likely only be noted on the weight and balance sheet created for when it was added, if you have the older superseded weight and balance sheets you should be able to find it.


Sent from my iPhone using Tapatalk

[kortopates]

[mention=6924]KSMooniac[/mention] M20K Encore.  Here's the page from my POH.  I don't have anything marked as installed.  Don't see any mention in logs.  But this is a charlie weight right?

this just shows it didn’t leave the factory with a charlie weight. Few mechanics make any effort to keep the equipment list updated.


Sent from my iPhone using Tapatalk

[PT20J]

If there is any question, you can always weigh the airplane and calculate a fresh W&B which really isn’t a bad idea if a lot of things have been added and subtracted. Math errors are not uncommon in a long chain of W&B updates and arms are sometimes uncertain.

[Marc_B]

So it's interesting that I found the following recommendation for ballasts in my POH (below), but still can't find any mention of charlie weight addition either in logs, POH or superceded W&B sheets.  However, using the last measured W&B Moment and weight and subtracting out the charlie weight (if it is a 6#, moment 1224.5) would put me right along the line suggesting -501 6# charlie weight.  So looks like it should be left in place for ideal CG according to POH...although I've always thought with no vacuum system, glass panel and MT prop I should have more useful load...the woes of UL envy

[Fly Boomer]

16 hours ago, Marc_B said:

Here's the page from my POH

Is that from the POH with your serial number, or from a generic POH for your model?

[Marc_B]

4 hours ago, Fly Boomer said:

20 hours ago, Marc_B said:

Here's the page from my POH

 

From my POH for my aircraft. 

[carusoam]

Somebody owes you a check mark next to the installed CW!   
 

Around here…

After purchase, Two things get checked often…
 

1) Useable fuel

2) WnB

 

The number of errors in both of these is incredible…

Oddly, factory numbers aren’t always perfect either….

Let us know what you find out if you go hunt down the real numbers…

WnB calculations are an engineering level class (Statics)… so it is pretty easy to mess up the math… but, omitting actual installed equipment… not engineering related at all… 

 

PP thoughts only, not a technical writer…

Best regards,

-a-

[Will.iam]

On 8/24/2022 at 12:29 AM, Marc_B said:

So it's interesting that I found the following recommendation for ballasts in my POH (below), but still can't find any mention of charlie weight addition either in logs, POH or superceded W&B sheets.  However, using the last measured W&B Moment and weight and subtracting out the charlie weight (if it is a 6#, moment 1224.5) would put me right along the line suggesting -501 6# charlie weight.  So looks like it should be left in place for ideal CG according to POH...although I've always thought with no vacuum system, glass panel and MT prop I should have more useful load...the woes of UL envy

This chart at your cg and weight i read as you don’t need a CW and since your documentation doesn’t show one you really need to weigh the plane and see if the cg is really still as 44.11 for if that sheet was recorded without a CW you will have a very different CG than the one shown now. 

[Will.iam]

My CW was removed just over a month after it left the factory. They used whiteout and signed and dated the removal. You can see the difference it made in my CG but I’m not sure what else was added or removed with that reweigh. But whatever it was porked me up 100lbs and that can’t be from dust and dirt as it was only a month after rolling off the factory floor.

[A64Pilot]

On 8/24/2022 at 1:07 AM, PT20J said:

If there is any question, you can always weigh the airplane and calculate a fresh W&B which really isn’t a bad idea if a lot of things have been added and subtracted. Math errors are not uncommon in a long chain of W&B updates and arms are sometimes uncertain.

This is the only correct answer, please don’t add or remove any ballast weight without reweighing the aircraft.

I’ve reweighed a few, and with few exceptions the original W&B was incorrect and in almost every case the aircraft weighs more than was thought, which is I guess one reason not to reweigh.

In the Army we had to re-weigh and recalculate CG every two years I believe, we could weigh completely full of fuel, or completely empty, so of course we almost always weighed full. I don’t know why GA airplanes must be weighed empty fuel.

Aft CG is slightly faster and more fuel efficient, but it’s also less stable and ballast of course reduces useful load and climb and T/O performance as it’s weight.

[Marc_B]

2 hours ago, A64Pilot said:

This is the only correct answer, please don’t add or remove any ballast weight without reweighing the aircraft.

I agree that you shouldn't make a change unless you know where you're starting to make sure you get where you're wanting to go.  My guess is that the charlie weight came from the factory...I have a dual alternator that isn't checked as included in my POH as well, but I can 100% verify it's there!  Getting some avionics and autopilot work done and I'll plan on an actual W&B and try to clean things up after that.

I'm learning that logs and POH/AFMS are much like memories...some memories are burned in and accurate...others just seem to fade with time until they're forgotten!  not sure if I need to take a master class on engineering, history, or archaeology?!

2 hours ago, A64Pilot said:

I’ve reweighed a few, and with few exceptions the original W&B was incorrect and in almost every case the aircraft weighs more than was thought, which is I guess one reason not to reweigh.

I suspect this is likely the primary reason that more GA aircraft aren't reweighed more frequently.  Which seems like a primary reason why you'd want to do it!

[carusoam]

Reweighing is an engineering lesson in itself…

There are a few threads around here that include a bunch of details that don’t come to mind….

How tough it can be to empty everything that doesn’t belong…

Emptying liquids from the tanks as needed….

Using the full fuel tanks method is interesting…. But includes a different error….  You need to know where the full line is. And fill it on the proper level ground… with the proper air level in the tires…

At least when you use the empty method…. You can also verify the useable fuel as you fill the tanks… back to the top….  Good time to calibrate some Ceis fuel level sensors too…

PP thoughts only,

-a-

[Mcstealth]

On 8/27/2022 at 1:12 PM, carusoam said:

Reweighing is an engineering lesson in itself…

There are a few threads around here that include a bunch of details that don’t 

PP thoughts only,

-a-

That was my next question; what is the proper way to weigh a Mooney?

[0TreeLemur]

On 8/26/2022 at 11:53 AM, A64Pilot said:

I’ve reweighed a few, and with few exceptions the original W&B was incorrect and in almost every case the aircraft weighs more than was thought, which is I guess one reason not to reweigh.

An A&P/IA once told me "nothing good ever comes from weighing an airplane".   I did it anyway and discovered an undocumented loss of 30 lbs UL.  We suspect this represents the original paint that was not removed when she was re-painted, and a 55-year accumulation of grease.

[0TreeLemur]

58 minutes ago, Mcstealth said:

That was my next question; what is the proper way to weigh a Mooney?

Follow procedure described in the S&MM

[Marc_B]

1 hour ago, Mcstealth said:

That was my next question; what is the proper way to weigh a Mooney?

Weighing procedure actually is listed in my POH and gives a method with full fuel calculation, and a method of draining fuel completely and re-adding unusable fuel.

[ArtVandelay]

I was able to put 33.5 gallons into each of my “32” gallon tanks. So the full tank method would result in 18lb loss of useful load.

[Fly Boomer]

On 8/25/2022 at 1:41 PM, Will.iam said:

My CW was removed just over a month after it left the factory. They used whiteout and signed and dated the removal. You can see the difference it made in my CG but I’m not sure what else was added or removed with that reweigh. But whatever it was porked me up 100lbs and that can’t be from dust and dirt as it was only a month after rolling off the factory floor.

Also says the speed brakes were removed, but nothing in the weight change column, and no revision of the empty weight? 

I must be missing something.