Weight shift
How far the moves when you move weight from one station to another, or how much weight to move to put the CG where you need it.
Planning and education aid. Not for primary navigation. Full disclaimer
Experimental: not yet fully verified. How results are checked
Moving 50 lb puts the CG at 82.97 in, a change of -1.33 in.
- Weight moved
- CG change
Provenance
- Computed by
- aviation.loading.weight-shift 1.0.0, core 0.1.0
- Model
- Weight moved ÷ total weight = CG change ÷ distance moved (FAA-H-8083-1B, chapter 2)
- Accuracy
- Exact for the entered weights and arms
- Notes
- 1 shown with the answer
- Cites
- Federal Aviation Administration, Aircraft Weight and Balance Handbook, FAA-H-8083-1B
Something look off?
How we got thisFormula, worked example, sources, and proof
Model: Weight moved ÷ total weight = CG change ÷ distance moved (FAA-H-8083-1B, chapter 2)
Show your work
CG change
weight moved × distance moved ÷ total weight50 × -60 ÷ 2,250= -1.33 inNew CG
CG now + CG change84.3 + -1.33= 82.97 in
The same steps an agent gets from the MCP server with explain: true.
Accuracy: Exact for the entered weights and arms
Worked example: 50 lb from the baggage area (150 in) to the front seats (90 in), 2,250 lb at 84.3 in. Source: Worked from the handbook proportion: 50 × (90 − 150) ÷ 2,250 = −1.33 in, so the CG moves to 82.97 in. It is golden test vector v001, and every build checks the tool still gives its answer within its tolerance.
You enter
- CG now
- 84.3 in
- Moved from arm
- 150 in
- Moved to arm
- 90 in
- Total weight
- 2250 lb
- Weight moved
- 50 lb
You get
- New CG
- 82.97 in
- Weight moved
- 50 lb
- CG change
- -1.33 in
Review: Not yet independently reviewed by a flight instructor (CFI).
Last verified: 2026-09-18, when a maintainer last confirmed this tool's sources at the issuer. See the sources ledger.
Status: version 1.0.0, core 0.1.0. See this tool in the verification report.
Checked against: 7 golden test vectors (download the test vectors, each with its source and tolerance). See how results are checked and every source.
Sources
- Aircraft Weight and Balance Handbook, FAA-H-8083-1B, Federal Aviation Administration, FAA-H-8083-1B. Chapter 2 (shifting the CG: weight moved ÷ total weight = CG change ÷ distance moved; adding or removing weight and ballast).
Terms
- CG: center of gravity
- The point where an aircraft's weight acts. It must stay inside the envelope in the POH for safe control. Source: Aircraft Weight and Balance Handbook
Experimental means this tool has not yet met the stable bar: at least 20 golden vectors, differential tests, and an independent worked example.
CG — center of gravity
The point where an aircraft's weight acts. It must stay inside the envelope in the POH for safe control.
Source: Aircraft Weight and Balance Handbook