Do you have to update weight and balance charts after installing new avionics?

Question

The POH always has weight and balance charts. Let's say you install some new avionics, hence changing the weight of the aircraft. Do you need to update the POH binder with new weight & balance charts? What about take-off/landing distance information?

Answer 1

For the US under the FAA, Yes you do!

From the FAA WB handbook

Changes of fixed equipment may have a major effect upon the weight of the aircraft. Many aircraft are overloaded by the installation of extra radios or instruments. Fortunately, the replacement of older, heavy electronic equipment with newer, lighter types results in a weight reduction. This weight change, however helpful, can cause the CG to shift, which must be computed and annotated in the weight and balance record.

For larger repairs.

Repairs and alterations are the major sources of weight changes. It is the responsibility of the FAA-certificate mechanic or repairman making any repair or alteration to know the weight and location of a change, to compute the CG, record the new empty weight and EWCG in the aircraft weight and balance record, and update the equipment lists.

Generally this is done by the shop that installs them. If you as the owner/operator installs them (which you are permitted to do to some extent) you may need to have a new WB drafted up.

This is also checked at anual every year,

The FAA-certificated mechanic or repairman conducting an annual or condition inspection must ensure the weight and balance data in the aircraft records is current and accurate. It is the responsibility of the PIC to use the most current weight and balance data when operating the aircraft.

Answer 2

Yes, any change in equipment attached to the aircraft requires a new weight and balance update. The weight and balance data are required for flight, but a photocopy is acceptable. In most operations I have been involved with, there is a binder or folder of required papers, and W&B is stored there, along with radio licenses, etc. POH formats vary, and some are not in binders. As a matter of practicality, the current W&B data must be readily available to the pilot and crew.

Answer 3

Yes, the empty weight and center of gravity data does need to be updated.

Anytime weight or center of gravity is changed, the mechanic must update the aircraft weight and balance. This information must be available to the pilot prior to flight, and is often included in the POH as an additional sheet or otherwise copied into the flight manual. In this way, the answer to your larger question is, yes.

However, if you are referring to the generic charts for the purpose of calculating weight and balance, the answer is no, these generic charts do not require updating. Conversely, an approved Airplane Flight Manual (AFM), will generally include weight and balance information that is specific to that aircraft. This information should be updated, or a note should be made invalidating the outdated data and referring the flight crew to the current data.

Typically when a change such as avionics installation takes place, the mechanic will compute a weight and balance change based on the item weight and installation position. However, the aircraft can be re-weighed to satisfy the same requirement.

The FAA states that mechanics should update the weight and balance record whenever an alteration such as an equipment change takes place. See the following paragraphs from page 1-3 of FAA-H-8083-1B, the "Weight and Balance Handbook".

Changes of fixed equipment may have a major effect upon the weight of the aircraft. Many aircraft are overloaded by the installation of extra radios or instruments. Fortunately, the replacement of older, heavy electronic equipment with newer, lighter types results in a weight reduction. This weight change, however helpful, can cause the CG to shift, which must be computed and annotated in the weight and balance record.

Repairs and alterations are the major sources of weight changes. It is the responsibility of the FAA-certificate mechanic or repairman making any repair or alteration to know the weight and location of a change, to compute the CG, record the new empty weight and EWCG in the aircraft weight and balance record, and update the equipment lists.

Note that the aircraft weight and balance record is generally a part of the aircraft maintenance logbooks, which are typically not carried on board the aircraft. The change in weight and balance is typically noted in the POH by inserting a photocopy or otherwise transferring the applicable information. In regards to these choices of where to store the required maintenance information, including the current weight and balance data, the operator is often free to choose according to convenience. There is no general requirement in 14 CFR to carry current empty weight and center of gravity data on board the aircraft for flights operating under §91.

Flights operating under 14 CFR, Subchapter G will, or may, have different operating requirements. For example, an air carrier authorized to operate under §135 is generally required to carry, on board the aircraft on flights operated under §135, a completed load manifest documenting weight and balance computations. However, for flights operated under §91, such documentation is not generally required.

_{Note: This answer addresses operations under FAA jurisdiction.}