Weight and balance question

Could you please show the weight and balance CG "envelope" chart, if there is one? If not, the appropriate table?

Also, is there an aft baggage compartment! Try the ballast there.
 
Here's what I have:

Weight Arm Moment

Empty. 1448 107.87 156173


Fuel (25 gal) 150.5 117 17608


Pilot 185 110 20350


Passenger 190 110 20900


Rear seats(ballast) 100 142 14200






Total. 2073 lbs (under max gross). Moment 229.22


This is still forward of allowable CG.
I like this plane but if you can't make those parameters within CG, that's pretty ridiculous. I should also add: it's not like this thing is decked out with avionics that would make the CG that far forward. Design flaw IMO.

With your aircraft W&B provided I plugged your numbers into my Musketeer template in my Aviation W&B app for grins. Hey, slow morning, I had time. With the pilot, copilot, fuel, and rear seat loads you stated your CG is on the forward line but within CG for flight. Your takeoff weight is 2073.5 (I rounded) and your arm is 110.65. Your CG will improve, that is it'll migrate toward center of the envelope as you burn off fuel. At least that's what the app says using the A23-19 template.
 
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Here's what I have:

Weight Arm Moment

Empty. 1448 107.87 156173


Fuel (25 gal) 150.5 117 17608


Pilot 185 110 20350


Passenger 190 110 20900


Rear seats(ballast) 100 142 14200






Total. 2073 lbs (under max gross). Moment 229.22


This is still forward of allowable CG.
I like this plane but if you can't make those parameters within CG, that's pretty ridiculous. I should also add: it's not like this thing is decked out with avionics that would make the CG that far forward. Design flaw IMO.

Here is what I came up with. Forward moment for MB-481 and After for gross weight 2070 is 228900 ; aft moment for 2070 is 244900.
 
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No, I just want to see his flight plan W&B calculations using the given datums. If he thinks he should be able to do this and that he is getting an incorrect result, the only way to answer that is to check his work. Maybe he is missing something, but I doubt it, I think he needs to put them in the back seat ...
I don't think that's a good answer, since if the 107 figure is wrong, that could end up putting him out of aft cg limit, and being too far aft is a lot worse than being too far forward. All the calculations volunteered above are useless if the cg on that sheet is wrong -- GIGO, and all that. The first step here is to confirm the accuracy of that 107 figure and if necessary correct it -- nothing else matters until that is done.
 
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I'll go back through the weight and balance sheets from maintenance calculations tomorrow . Every time I do this calculation with the 110.1 empty aircraft arm (as stated in the POH), I can get the CG just perfect. However, with a 280 lb passenger in the front seat (fully back position with an arm of 112) and the calculated empty arm of 107.87, I couldn't get it within CG limits even if I added 80 lbs in the back seat and took ZERO fuel! Doesn't seem right to me.

FYI, with a pilot at 185 in front, passenger at 280 in the back seat, and 25 gallons? Arm is 113.45. Golden.
 
I don't think that's a good answer, since if the 107 figure is wrong, that could end up putting him out of aft cg limit, and being too far aft is a lot worse than being too far forward. All the calculations volunteered above are useless if the cg on that sheet is wrong -- GIGO, and all that. The first step here is to confirm the accuracy of that 107 figure and if necessary correct it -- nothing else matters until that is done.

What? The 107 is from the aircraft W&B sheet. How do you figure that's wrong?
 
Here's what I have:

Weight Arm Moment

Empty. 1448 107.87 156173


Fuel (25 gal) 150.5 117 17608


Pilot 185 110 20350


Passenger 190 110 20900


Rear seats(ballast) 100 142 14200






Total. 2073 lbs (under max gross). Moment 229.22


This is still forward of allowable CG.
I like this plane but if you can't make those parameters within CG, that's pretty ridiculous. I should also add: it's not like this thing is decked out with avionics that would make the CG that far forward. Design flaw IMO.

Perhaps the Beechcraft engineers who designed the aircraft didn't anticipate the super sizing of the population 30-40 years after the aircrafts' manufacture. There are some GA airplanes your passenger may not even be able to get into. I wouldn't call designing an aircraft the would be suitable for the vast majority of the population at the time a design flaw or ridiculous.
 
What? The 107 is from the aircraft W&B sheet. How do you figure that's wrong?
The fact that it's apparently impossible for the OP to load the plane within the forward cg limit with two normal front seaters and fuel (which is what I think he said in the first post) -- that just doesn't make sense. I've seen this before, and each time it turned out someone somewhere along the way had screwed up the empty cg computations and come up with a computed empty cg that was 2-3 inches farther forward than where it really was. That is an invitation to loading the plane out of aft cg limits while thinking everything is OK, and loading out of aft cg limits can kill you.
 
Perhaps the Beechcraft engineers who designed the aircraft didn't anticipate the super sizing of the population 30-40 years after the aircrafts' manufacture. There are some GA airplanes your passenger may not even be able to get into. I wouldn't call designing an aircraft the would be suitable for the vast majority of the population at the time a design flaw or ridiculous.
That would be a reasonable assumption if the computed empty cg wasn't almost 3 inches farther forward than the sample empty cg, which certainly is not due to the average size of the population either then or now. It's unusual, and suggests someone made a math error in the empty cg computations somewhere along the way. That sort of variance along with the inability to stay in the cg limits with even normal loads suggests something is wrong with the data on the current empty W&B sheet. Sure, it might really be that way, but there are enough red flags for me to say an audit of all the past empty W&B computations is in order.
 
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And I ran the provided average size numbers in a previous post and found it forward but inside the envelope. The 280# copilot is a problem but that's solved by seating him in the second row. In that case the CG is centered in the envelope.
 
Doesn't matter. It's the official document for that plane and looking at previous weight, the work performed, and subsequent weight, it appears normal. That's what we pilots are required to carry on board and to use to determine our W&B for a flight.
 
Doesn't matter. It's the official document for that plane and looking at previous weight, the work performed, and subsequent weight, it appears normal. That's what we pilots are required to carry on board and to use to determine our W&B for a flight.
The fact that it's official doesn't mean it's right, and if it's wrong, your airplane may not have acceptable pitch control/stability despite the numbers saying things should be OK. As I said above, I've seen them wrong before, and I'm sure I'll see them wrong again, and the laws of physics still apply no matter what someone writes on that piece of paper. This is definitely a "trust but verify" situation, and my trust in the accuracy of his W&B document is shaken by the factors already mentioned, so verification becomes essential.
 
This is why when I get a plane, I reweigh it, I want to know what I have.
 
I'm glad I fly a 182 and don't need to worry about such trivial things as a W&B.

:goofy:
 
Blah, blah, blah. The mechanics have been signing it off for 10 years on the displayed W&B. That's THE document that the pilot is bound to use. I'm all for weighing airplanes. I've assisted the weighing of my own several times as I've done mods. But short of that? The aircraft W&B is an important document and the operator is bound by it until a new one is produced. Man, you guys sure make a simple issue into a big problem.

The OP would do well to spend a couple of dollars and install the W&B app on his phone. It allows the pilot to juggle loads to stay inside the envelope. It includes the CG envelope and plots the points as you change the weight distribution. Very handy tool for situations like the one he's in.
 
The fact that it's official doesn't mean it's right, and if it's wrong, your airplane may not have acceptable pitch control/stability despite the numbers saying things should be OK. As I said above, I've seen them wrong before, and I'm sure I'll see them wrong again, and the laws of physics still apply no matter what someone writes on that piece of paper. This is definitely a "trust but verify" situation, and my trust in the accuracy of his W&B document is shaken by the factors already mentioned, so verification becomes essential.

After re reading this thread, before I would spend hours going through old w/b papers I would re check my calculations. What Stewart has come up with is a 180 lb pilot and a 190lb passenger is within limits. Change the passenger to 280 lbs and the passenger has to move to the back seat, which sounds right to me.
 
Blah, blah, blah. The mechanics have been signing it off for 10 years on the displayed W&B. That's THE document that the pilot is bound to use. I'm all for weighing airplanes. I've assisted the weighing of my own several times as I've done mods. But short of that? The aircraft W&B is an important document and the operator is bound by it until a new one is produced. Man, you guys sure make a simple issue into a big problem.

The OP would do well to spend a couple of dollars and install the W&B app on his phone. It allows the pilot to juggle loads to stay inside the envelope. It includes the CG envelope and plots the points as you change the weight distribution. Very handy tool for situations like the one he's in.

There seems to be two loads subject in this thread. The weight and balance calculation I saw mentioned no 280lb passenger. That one had a lighter 'common load' where the question became the overall suitability of the plane.
 
With your aircraft W&B provided I plugged your numbers into my Musketeer template in my Aviation W&B app for grins. Hey, slow morning, I had time. With the pilot, copilot, fuel, and rear seat loads you stated your CG is on the forward line but within CG for flight. Your takeoff weight is 2073.5 (I rounded) and your arm is 110.65. Your CG will improve, that is it'll migrate toward center of the envelope as you burn off fuel. At least that's what the app says using the A23-19 template.

With 25 gals fuel, 185# pilot, 280# aft seat passenger, and omitting the 100# ballast the arm is 113.45.

Now you have a comparison.
 
MB-481 and After

Forward CG limit for weight 2070 is 110.5, Aft CG limit for 2070 is 118.3

Forward CG limit for weight 1500 is 107.8, Aft CG limit for 1500 is 118.3
 
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A little bit of a overstatement.

2" on the C of G, won't make a life threating situation on most 4 place aircraft. After getting some hours on a airframe you should have a feel for what the plane can take [of course this statement is for educational/theoretical purposes only, follow the FAR and your POH].

Would 4" be ok? What about 3"? 6", but only if you've done it a lot and have a feel for it?

The problem is not how it functions for takeoff, cruise, and landings, but how do you develop a feel for what it takes to get it out of a spin at 2" forward, vs. within the envelope?

My friend weighs 270 pounds and I have the same problem with my Cardinal. He doesn't ride when I have more than 40 gallons in my tanks. He gives me a hard time and calls me a wimp, saying "his airplane can do it no problem", but he isn't taking into account what can happen when things go wrong.
 
Blah, blah, blah. The mechanics have been signing it off for 10 years on the displayed W&B.
Doesn't make it right, smart, or safe to use without verifying its accuracy if you have any reason at all to doubt that accuracy, and there appears to be reason for doubt.
 
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That's an owner issue that I agree with but for the pilot flying today? The W&B document is the basis for loading his airplane. And that was the question.
 
That's an owner issue that I agree with but for the pilot flying today? The W&B document is the basis for loading his airplane. And that was the question.
Makes no difference. If that plane can't be controlled in pitch because the plane is out of cg limits, it's the pilot who gets killed, not the owner. And yes, pilots have been killed by loading out of cg before. You just can't say, "Well, that's what the numbers on the paper said" if those numbers don't make sense when you run a W&B problem.

Kinda like the discussion in another thread about the transposed altimeter digits -- the pilots should have had alarm bells ringing in their heads when the ATIS altimeter setting was .30 lower than the settings they'd been getting from ATC. PIC's get the big bucks because they're supposed to be able to tell that something's wrong when things like that happen, whether it's paperwork on the ground or information over the radio in the air. The buck stops here, and in this context, "here" is in the lap of the PIC. Heck, the FAA even put that in writing:
Sec. 91.3

Responsibility and authority of the pilot in command.

(a) The pilot in command of an aircraft is directly responsible for, and is the final authority as to, the operation of that aircraft.
 
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Another passenger instead of pilot/PIC example. All he is missing is a chute.
 
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