Aft CG or Fwd CG... where are you operating?

[Yourpilotincommand]

My E model is way aft from its original, and thought that was typical since starters, generators, and avionics all got lighter through the years... and stuff gets added in the back.  However I see some of you have fwd CG issues. Please share your empty weight CGs, etc..

[David Lloyd]

Share yours.

My C is 1771 empty weight, 46.15 arm, 81729 moment.  Recently weighted.  I do have a 3 blade prop (15 pounds or so over a 2 blade)  and Power Flow exhaust (several pounds over stock) moving the CG forward but also a rear mounted battery. Weight includes 8 quarts of oil, bladder tanks (30 pounds), wingtips, all the mods.  Even after getting rid of the old radios, it is the fattest C model around.

[Ragsf15e]

My F is 1705, 45.2 CG, and 77,157.72 moment.  Pretty good UL of 1035, but the 3 blade prop adds weight up front.  From this CG (and most Mooneys), you can load it almost at will without going out of balance.

My weight has been calculated from 1968, so it’s probably not exact... 

[JimB]

1 hour ago, Ragsf15e said:

My F is 1705, 45.2 CG, and 77,157.72 moment.  Pretty good UL of 1035, but the 3 blade prop adds weight up front.  From this CG (and most Mooneys), you can load it almost at will without going out of balance.

My weight has been calculated from 1968, so it’s probably not exact... 

I just recently weighed my 69 F and it is 1702 and 44.1 CG. I agree on the loading. I have ran the numbers with the weight all over the aircraft and it doesn't seem to make much difference in CG. I'm pretty pleased to be able to carry full fuel and almost 700 lbs. With just my wife and I, I'm not sure there is enough room in the aircraft and thru that little baggage door to overload the aircraft. 

[PT20J]

My ‘94 J is 46.1” 1914 lb. empty. 

[David Lloyd]

I checked yourpilotincommand's weight and balance page against my spreedsheet, it appears correct in it's calculations.  However: I really think my CG is further aft than most with the rear mounted battery, the Stec roll and pitch servo controllers, the pitch servo, KG102 for the King HSI, remote radio for the PAR200B and ELT.  And yours is 1 full inch more rearward than mine! That's an inch that makes a big difference.  I hope some others post their numbers for their C, D, or E.  Especially E.  

[carusoam]

There is a picture of an M20C that was loaded incorrectly...

Somebody insisted their new2them M20C was a magical five seat short body...

Thus proving... it is important to know your real WnB...

The closer you get to the limit... you run out of two things...

• Power
• Lift

While loading up the weight... know that it requires...

• More AoA to generate the proper lift, which causes...
• More drag...

If you have ever run a car down the 1/4 mile... you get a feel for how...

• weight slows things down....
• Warm OATs generate less power...

Combining that knowledge together for flight...

• Warm OATs cause high DAs...
• WnB affects the ability to get off the ground... in a timely manner...
• Don’t unknowingly exceed WnB limits at high DAs...

Other things to avoid...   taking pics of your fifth passenger in the baggage area...Pics have a way of circulating faster than the accident report can be written...

Then people get a tad mean discussing your fifth passenger’s body weight... vs, the weight limit of the baggage area...

PP thoughts only... not a CFI...

Best regards,

-a-

[Ragsf15e]

I’ve looked through mine since I have W&B calculations back to the factory in 1968.  It’s hard to track the addition/subtraction of some items.  Additionally, it was done by hand until ~1995.  There’s even an error on the first one from the factory where they made the first calc after modifying it with electric gear.  There’s a crossout in pencil and then correction.  
 

If you’re going back 50 years, I think theres a good chance someone made an error in that time.  I don’t think it would be difficult to make an error that could be very hard to find but could significantly affect your cg.

Do you have the original cg from the factory?  How different did it start out?

[mark21m20c]

M20C Weighed this year 1598 LBS empty weight oil included . Alternator Light weight starter no vacuum system  added stec30 auto pilot and most of the mods . Aircraft 15 LBS heavier then it was in 1967. CG came in at 46.7 . 

[carusoam]

Back to the original question....

Where do people operate their WnB...

The envelope is quite large, but...

When I fill in the data... for my favorite flights...

I can put dots in the various corners of the envelope by who sits where, and how much fuel we are bringing...

Unlike Brand B, the Mooney doesn’t usually fall outside the envelope when the fuel weight changes....

 

So... always check to see what happens as the fuel load goes to minimum....

PP thoughts only,

-a-

 

[Yourpilotincommand]

My empty weight is 1,667 lbs with a CG of 47.1”. I’ll have to open the original docs to see what it was back in ‘66. I forget off the top of my head. The CG goes to the aft limit even if I put 2 light weight people in the back, me and a light weight copilot up front, no luggage.. and can carry 36gal of fuel. 

[gsxrpilot]

21 minutes ago, Yourpilotincommand said:

My empty weight is 1,167 lbs with a CG of 47.1”. I’ll have to open the original docs to see what it was back in ‘66. I forget off the top of my head. The CG goes to the aft limit even if I put 2 light weight people in the back, me and a light weight copilot up front, no luggage.. and can carry 36gal of fuel. 

I just gotta think there is a mistake somewhere with your 47.1" CG. 

Your CG is out the ass end and every other Mooney in the world is trying to move the CG aft to get a couple of extra knots. It just doesn't make sense.

[mark21m20c]

I think your empty weight is off. My CG is close to yours at 46.7 (m20c).

[Ross Taylor]

My '66 E has an empty weight of 1750 and a pretty-aft CG of 46.84 inches.  Since neither my wife nor I are large people, we have to watch our loading.  46.84 is better than what my most recent W&B sheet showed, though, because of some bad math done by a prior shop.  Check out this thread for the docs and some great enginerd explanations from the awesome MSers.

 

[Yourpilotincommand]

19 minutes ago, mark21m20c said:

I think your empty weight is off. My CG is close to yours at 46.7 (m20c).

Oops thanks! I’ll edit it.

[Yourpilotincommand]

41 minutes ago, gsxrpilot said:

I just gotta think there is a mistake somewhere with your 47.1" CG. 

Your CG is out the ass end and every other Mooney in the world is trying to move the CG aft to get a couple of extra knots. It just doesn't make sense.

I’ll upload my latest W/B pic when I get to the hangar tomorrow. I even checked for rocks hiding in the tail one when I first bought it, lol

[Ragsf15e]

41 minutes ago, Yourpilotincommand said:

I’ll upload my latest W/B pic when I get to the hangar tomorrow. I even checked for rocks hiding in the tail one when I first bought it, lol

It’s probably not the latest one that’s the issue... go back a few and find out how it has changed over time.  Look for a jump aft, then validate the math and common sense.

[cliffy]

One item to look at if you are digging deep into your W&B is to look and see if who ever did it before included the engine oil weight and arm in the calculations for Empty Weight. 

Our airplanes (Certified under CAR-3) are calculated for Empty weight and CG with all engine oil drained (specifically in a level attitude).  The "official" Empty Weight and CG has to be listed without engine oil. 

We are supposed to add in the weight and arm of the engine oil into our "Useful Load" calculations for every flight. Engine oil weight subtracts from useful load in CAR-3 airplanes. 

We can however take a correctly annotated Empty W&B and add in the weight and arm to the EW CG for a correct stating point for all W&B calculations for flight.

So we lose about 15 lbs of empty weight availability with full oil (8 qts) IF our W&B calculations have been done correctly.

[Rjfanjet]

68C. 1585 empty, 42.18 empty, 990 useful load. I do have a 3 blade prop and Concorde 35AXC up front. Have a new Skytec starter on my shelf to replace the heavy one up front. 

[ArtVandelay]

One item to look at if you are digging deep into your W&B is to look and see if who ever did it before included the engine oil weight and arm in the calculations for Empty Weight. 
Our airplanes (Certified under CAR-3) are calculated for Empty weight and CG with all engine oil drained (specifically in a level attitude).  The "official" Empty Weight and CG has to be listed without engine oil. 
We are supposed to add in the weight and arm of the engine oil into our "Useful Load" calculations for every flight. Engine oil weight subtracts from useful load in CAR-3 airplanes. 
We can however take a correctly annotated Empty W&B and add in the weight and arm to the EW CG for a correct stating point for all W&B calculations for flight.
So we lose about 15 lbs of empty weight availability with full oil (8 qts) IF our W&B calculations have been done correctly.

Then explain this from J manual:

[Yourpilotincommand]

10 hours ago, Ragsf15e said:

It’s probably not the latest one that’s the issue... go back a few and find out how it has changed over time.  Look for a jump aft, then validate the math and common sense.

I had a complete fresh W/B a couple of months ago. Not much different from the previous one. I’ll attach a photo later today

[bradp]

My J is 45.8 and 1724 - she went on a diet 

[Ragsf15e]

Oh interesting.  Well sheesh, you’ve found the first tail heavy mooney?! Maybe time for a 3 blade prop?

[N205S]

1987 M20J 205 with the 2900lb Gross Weight Increase STC. W&B done in 2015. Reported to weigh 1924lbs, 44.39 CG, with 976lb useful load. Have the 3-blade Hartzell Top Prop up-front. Looking at these other numbers, looks like I could probably shed a few pounds and get to 1000lb useful load.

That said, I've not been able to get it out of CG with any loading/fuel configuration yet but I'm typically operating with a more forward CG.

Edited August 20, 2020 by N205S

[gsxrpilot]

1 hour ago, Yourpilotincommand said:

I had a complete fresh W/B a couple of months ago. Not much different from the previous one. I’ll attach a photo later today

I would be curious to compare the very first or original W&B with what you have now.