Weight and Balance report

[A BELLAND]

Can someone advise me on how you go about making up a W@B report.The aircraft is a PIPER J-5 and has a 135 H.P. with 18 cowls and tail.Is there a way to figure out the balance after the aircraft is weighed or do you use a old W@B and subtract the original weights and arm of parts removed and then add the weights and arm of the new parts.I have done W@B calculations but always was working of a empty W@B and adding pass.,fuel and baggage.I have never had to make a new weight and balance report and i am lost.
This plane is registered in the owner maintenance category in CANADA.
Thanks in advance for any help offered,Aurele Belland

 

[SuperCub MD]

You can do it on paper or on scales. You might want to find a pro who does this stuff.

Question? I know it may be great for a lot of folks, and I'm not familiar with this "owner maintenance" category...so please take this in the best possible way....

Once a Canadian registered aircraft is registered in this category, I would assume that it removes any chance of export? Being close to the border, I deal with a lot of aircraft that are imported back into the USA and given standard airworthiness again. I can't imagine (and kinda hope) that any "owner maintained" aircraft could never get a standard airworthiness in the US again?

 

[CaptFox]

MD...

I'm no Expert here on your question but am from both sides of the border and looked into "OWNER MAINTENANCE" on a Canadian plane I owned but opted to import it back to US a while back. I believe it can be brought back up to a Private or Commercial Registration but it entails alot of work, Basically a fresh Annual and conformity inspection by the appropriate rated People and Transport Canada and complete reissueance. Also Canadian Maintenance regs are much strickter than US . I believe could be exported back to the US if it was brought back up to speed?

Owner Maintenance Category I believe still requires the same requirements as regular maintenance but can be done by the owner but I'm not 100% sure...So if this is the case in theory its not a big deal???????????????????????????????????


David.

 

[klm_ak]

You need to take some measurements while the plane is being weighed and is level (the leveling method varies by J-5 model).

The datum for the J-5 series is wing leading edge, so all measurements should be perpendicular (horizontal) from a plumb line off the wing leading edge while it is in the "level" condition.

Measure to the axle center of the main wheels,
Measure to the axle center of the tail wheel.

Multiply the distance in inches to the tail wheel by the weight on the tail wheel and,
Multiply the distance in inches to the mains by the weight on both mains,
Add those two numbers together
Divide by the total weight (both mains plus tail wheel weight)

This will give you the CG measured from the leading edge.

An example
J-5C leveled by plumb bob from machine screw at door frame channel to hole in plate near rear seat.

Distance of a level line from plumb line over wing leading edge to mains +1 inch (positives are behind the wing leading edge, negatives toward the prop)
Distance of a level line from plumb line to tail wheel axle +201 inches

Weight on Left Main 470 lbs
Weight on Right Main 479 lbs
Weight on tail wheel 35.0 lbs (remember to subtract anything used on top of the scale to prop the tail wheel up)

Tail Moment = 35 lbs * (+201 inches) =7035 inch-pounds
Main Moment = (470 + 479) lbs * (+1 inch) = 949 inch-pounds

Total Moment = 7984 inch-pounds
Total Weight = 470+479+35 = 984 pounds

CG relative to leading edge = 7984 / 984 = 8.11 inches (which would be out of envelope, so my made up numbers wouldn't work well for a J-5C)

Note that an error of just one pound in the tail weight will make a difference of 0.2 inches in the CG calculation in this example. An error of one inch in measuring the distance to the mains will move the calculated CG .7 inches.


When making only a minor change, e.g. adding or removing an instrument, most I.A.'s will simply use the add/subtract based on arm calculation from the current W&B sheet to come up with a new and approved. On most of the mod's I've made if you change something major like tail feathers/paint/fabric/engine the STC required a new actual weight.
KL

 

[SuperCub MD]

Weight X Arm = Moment, add up the weight, add up the moments, and divide to get the CG. I think even private pilots are suppose to be taught this stuff?

Right now, most imported planes need just a annual and conformity inspection to receive a standard airworthiness. Unfortunatly, most I see after import do not even come close to complying with the type certificate, much less any mods, and I end up cleaning up the paperwork and mod mess. Honestly, most of the AI's and ASI that currently do most of the importing don't seem to know what the hell they are doing. I can only imagine what these "owner maintained" catagory planes are going to end up being if they can be imported.

 

[Aviator]

Aurele, what you are asking about is called an Amendment to the Weight and Balance Report, if done by weighing and measuring the arms of components added and removed. Or, it's a Weight and Balance Report, if the entire aircraft is weighed and a new empty weight and CG is computed, as explained by the guys here. You might want to check and make sure your O/M authority covers these procedures, since only a limited set of maintenance activities are O/M authorized.

As for export of O/M aircraft (I'm no expert on this), a CofA for export will not be issued by Transport Canada unless the aircraft first regains its normal or utility category CofA in Canada. This usually means complete overhaul of every time/cycle limited component, the airframe is recertified (by a Cat B, major airframe repairs and modifications, licensed engineer, as needed), and new or reissued I.D.'s are installed on all affected components, including airframe. (Don't forget, that once a bird becomes OM, all I.D. plates, prop hubs, etc., are punch stamped with an "X". So beware of any "X-ed out" components you might run across).

Hope this helps,

S.F.
Nick

 

[A BELLAND]

W@B REPORT

Thanks everyone for your help.

The O/M category in Canada is to help keep older planes flying.It was intended as a way to deal with a lot of the issues involved with maintaining these planes.It opens up older aircraft for afforable use as it inables the owner to repair or modify without the use of a A.M.E. The aircraft must conform to acceptable standards and is for private use only.
As far as the W@B question, i have to have a weight and balance report when the Transport Canada inspector looks at the aircraft.I was not shown how to do this when i got my PPL,was shown how to do basic W@B problems working of the empty weight and arm.
Thanks again for your help,Aurele Belland

 

[Aviator]

Aurele, preparing a W&B report is a maintenance function, not a flight crew function. That's why you didn't have to do one on the PPL exam. Although the concept is the same, a W&B report is not the same as the W&B you compute as a pilot. The W&B you calculate before you go flying determines your take off (and possibly landing) weight and CG (e.i., Empty Weight/CG + fuel + oil + other fluids + load... This changes everytime you go flying.

You already proved to TC you can do this. What they want to see is the plane's W&B report (maintenance), the document that shows your plane's empty weight/CG which you need (as a pilot) to begin calculating your W&B before you go flying. It's supposed to be in your Journey Log. Further, you (or an AME?) have to prepare an amendment to your W&B report everytime you add/remove components AND make an entry in both logs detailing the work AND certification that the "W&B Report has been Amended." The idea is to let the next pilot (you or someone else) know which W&B report he should use. The W&B report doesn't change unles you add/remove components.

Your best bet is to get an AME to help you with this.

S.F.
Nick

BTW, hope you don't plan on putting in electrics! You sure don't want to have to do a Load Analysis from scratch.

 

[SuperCub MD]

I think it's the same theory that you are taught as a pilot, but I guess the maintenance end does go into it deeper (I have been both for to long, and I forget the differences).

AC43.13-1A/2B contains a entire chapter on weight and balance. I don't know if anyone ever uses it in Canada, or if Canada has something similar, but in the US it is basically the Bible that we use to maintain older aircraft. It would be helpful for you to have a copy, if only just for reference. It should be available from any source that sells aviation publications.

I am curious about the OM thing, I hope it doesn't come across that I'm trying to be mean, I'm not. Thanks for the info on the X stamped data plates. Is there any training required of the owner to do this? What are the owners responsabilitys and limitations? Are you required to use all PMA'ed, certified parts and hardeware? Comply with STC's for modifications?

 

[A BELLAND]

W@B REPORT

Hi Everyone
Thanks again for all the input.
The AC43.13-1A/2B is called the bible in Canada to and is refered to by everyone as the standard to which to base all repairs and maintenance.
I have had a copy for years and maybe not as worn as some it shows its use.
The W@B question was posted as i was looking for input from some people that do this sort off thing all the time.I did not know how to do the procedure and wanted to know for myself so i was reading and asking about it.
The Owner Maintenance class is intended for recreational and private use by owners or you can use the service of a A.M.E.There is no training BUT the work must comply to acceptable standards.I know that there will be varrying quility of work performed but this happens with A.M.E.s as well as private owners.
THIS SITE IS GREAT and i use it all the time. thanks Aurele Belland

 

[A BELLAND]

owner maintenance

I did not answer all the questions posted.
You do not have to use certified parts or PMA'ed parts.You can build just about anything for your plane or buy from someone who can build it for you.you as the owner are responsible for the airwortheness of the aircraft.This opens the door to people who like to work on or modify there planes but the plane must meet acceptable standards.something like the upper cabin X brace can be done with NO paperwork but should be done to aircraft standards as far as material and workmanship.
Aurele