Weight and Balance Questions

For the A&P’s out there, when you complete a new W&B:

1) Is a notation required to placed in the airframe logs?

2) When you sign the W&B, does it need to be dated?

3) is it required to list the date of the superseded W&B?

Thanks,
Daryl

Doesn't need to be done by an A&P. It should go in the Weight and Balance section of the Flight Manual! I always put an entry in the log book as the one in the flight manual likely gets lost but not required. When you do a W&B update, you are also supposed to do an Equipment List update and if it is for an item that uses electricity you should also have an updated electrical load analysis. I really hate getting an airplane that has a dozen W&B updates loose in the records with no updated equipment list Owners just don't understand the importance of maintaining conformity on their aircraft.

"Weight and Balance Revision Record Aircraft manufacturers use different formats for their weight and balance data, but Figure 7-3 is typical of a weight and balance revision record. All weight and balance records should be kept with the other aircraft records. Each revision record should be identified by the date, the aircraft make, model, and serial number. The pages should be signed by the person making the revision and his or her certificate typeand number must be included. The computations for a weight and balance revision are included on a weight and balance revision form. Appropriate fore-and-aft extreme loading conditions should be investigated and the computations shown. The date those computations were made is shown in the upper right corner of Figure 7-3. When this work is superseded, a notation must be made on the new weight and balance revision form, including a statement that the new computations supersede the computations dated “MM/DD/YY.”

ref - https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/media/faa-h-8083-1.pdf

I'm not an A&P so I'll let you read the information and answer your questions yourself.

I usually agree with dga - but for Cubs and early Aeroncas, be aware that putting the aircraft on scales can turn it into 1PCLM. If you weigh it, do yourself a favor and do not note the event on a 337 or in your logbook.

i have converted at least one Supercub back to 2PCLM by detecting a serious error in the weighing process and going back to factory numbers, computing each addition/subtraction.

We have one currently - a really nice 160 Super Cub with bunches of field approvals and STCs. Each 337 has the notation "aircraft will be weighed on assembly." The owner has no choice - it must be weighed. Result - a beautiful Super Cub with a 400# useful load.

Some may applaud the honesty here, but those same folks will load it up with two guys, camping gear, and full fuel. That is in fact a violation of the regs - computing a weight and balance is not.

As usual, opinion.

bob turner said:

I usually agree with dga - but for Cubs and early Aeroncas, be aware that putting the aircraft on scales can turn it into 1PCLM. If you weigh it, do yourself a favor and do not note the event on a 337 or in your logbook.

i have converted at least one Supercub back to 2PCLM by detecting a serious error in the weighing process and going back to factory numbers, computing each addition/subtraction.

We have one currently - a really nice 160 Super Cub with bunches of field approvals and STCs. Each 337 has the notation "aircraft will be weighed on assembly." The owner has no choice - it must be weighed. Result - a beautiful Super Cub with a 400# useful load.

Some may applaud the honesty here, but those same folks will load it up with two guys, camping gear, and full fuel. That is in fact a violation of the regs - computing a weight and balance is not.

As usual, opinion.

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I never said to weigh the airplane, just where the Weight and balance data should be! Errors in Wt&Dalace are very common. Every airplane I’ve owned has either had errors, or the W&B was nonexistent. When I got the Howard back in 1996, there hadn’t been a W&B calculation since the early 1950s when it still had the original military radios. When I got it home and actually did the calculations, with just me, full fuel in the front tank and full oil it was 10” forward of the forward limit!
Took 26 lbs of lead on the tail to get it where it should be.


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I was only disagreeing about entering it in the logbook (or on a 337).

We had one where the mechanic used mixed data (easy on a Super Cub, since two different data are on the same darn page in the AFM). The result was an airplane that could never be loaded within the envelope. It flew like that for two decades.

frequent_flyer said:

"…including a statement that the new computations supersede the computations dated “MM/DD/YY.”

ref - https://www.faa.gov/regulations_policies/handbooks_manuals/aviation/media/faa-h-8083-1.pdf

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That publication is not a regulation.

I dont recall the quoted statement as being required. But I have been wrong, and am willing to learn, I guess, if I have to.

Dave Calkins said:

That publication is not a regulation.

I dont recall the quoted statement as being required. But I have been wrong, and am willing to learn, I guess, if I have to.

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The superseded W/B records for my PA-28 have a "superseded [date]" annotation. The new records do not reference the superseded records but they do include a tabulation of the previous weight, arm, and moment.

For my FX-3 I keep a cumulative equipment list and a running tally of weight, arm, and moment for each change. The whole page gets replaced each time it is updated so there is only one paper W/B record in the aircraft.

At my last PA-28 inspection my IA cautioned me that, if I was to continue flying with the rear seats removed, I should have a separate W/B for that configuration. I suppose it just depends what itch the local inspector wants to scratch on the day it's ramp checked.

frequent_flyer said:

The superseded W/B records for my PA-28 have a "superseded [date]" annotation. The new records do not reference the superseded records but they do include a tabulation of the previous weight, arm, and moment.

For my FX-3 I keep a cumulative equipment list and a running tally of weight, arm, and moment for each change. The whole page gets replaced each time it is updated so there is only one paper W/B record balance in the aircraft.

At my last PA-28 inspection my IA cautioned me that, if I was to continue flying with the rear seats removed, I should have a separate W/B for that configuration. I suppose it just depends what itch the local inspector want to scratch on the day it's ramp checked.

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Your IA is correct if you get ramped it’s possible you may get a violation. For years we changed the seating configurations flying 135. In the early 90’s the FAA said no mas. We had to come up with a training program for pilots to change configuration along with different W&B’s.

Agree. But it is easy - just have alternates on board. My Dceathlon carries wheel pants on/off variations. Really just an extra line or two on a single sheet.
Then, I carry a loaded computation for two reasonable scenarios.

Definitely have alternatives. That’s what I did with the Howard, one with rear seat installed and one without. My Clipper I’ll have 4, with and without on wheels, with and without on skis. Pretty simple.


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No, not difficult to do, but the PA-28 is so tolerant of loading that it would be very hard to get it outside the allowed envelope. I did find that removal of the rear seats allowed utility category operation which was not possible with the rear seats fitted. Some sample loadings shown here -