Weight & Balance
Loading with verified aircraft data (Cessna 172S POH): occupants, stations, baggage, fuel, empty weight and moment, centre of gravity on the envelope, in or out of limits.
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Enter the basic empty weight and moment of your airplane, then the people, baggage and fuel. The table works exactly like the POH loading problem: every item's weight times its arm gives its moment; the totals give the ramp weight, the takeoff weight (after the start, taxi and runup allowance) and the landing weight (after the planned fuel burn). The centre of gravity is total moment divided by total weight.
Cessna 172S only: Information Manual 172SIM incorporating POH/AFM Revision 5 (19 July 2004, P/N 172SPHUS05), serials 172S8001 and on, conventional instrument panel — not the G1000 (NAV III) handbook. For training — not for flight planning of a specific airplane; use the POH/AFM for your serial number. The default empty weight and moment are the POH sample airplane, not yours.
On the stage the amber dot is the takeoff point and the ring the landing point on the normal (solid) and utility (dashed) envelopes; the dashed line between them is the fuel burn, along which the CG moves as the 48-in fuel arm empties. Switch to the moment view to see the same check as POH Figure 6-7. The station scale below shows where each load sits; drag the cyan markers to move the front seats or the baggage inside their printed ranges and watch the CG triangle move.
Every limit that is broken is named with its POH reference: maximum ramp, takeoff and landing weight, forward and aft CG at the actual weight, baggage area limits, and the utility-category rule that the rear seat and the baggage compartment must be empty. Practice gives you random loadings to judge before the answer is shown.
Assumption: usable fuel at 6 lb/gal and arm 48.0 in, as the POH loads it; occupants at the average-seat arm (37 in) and baggage at the centre of each area unless you move them; the default empty weight and moment belong to the POH sample airplane, not to yours.
Data: POH section 2 (weight limits, CG limits normal and utility, p. 2-7/2-8; fuel 53.0 usable gal, p. 2-11) and section 6 (stations of Figure 6-3: front seats 37 in within 34–46, rear 73, baggage area 1 95 in within 82–108, area 2 123 in within 108–142, usable fuel 48.0 in at 6 lb/gal; sample loading Figure 6-5). Transcribed twice independently (text layer and page image), diff empty.
Limits: forward 35.0 in at 1950 lb or less, straight-line variation to 41.0 in at 2550 lb (utility 37.5 in at 2200 lb); aft 47.3 in (utility 40.5 in) at all weights. A point exactly on a limit is within limits. The envelope charts start at 1500 lb, as Figures 6-7 and 6-8 do. Figure 6-7 draws the sloped forward edge straight in moment space; the section 2 limit is a slight curve there (the drawn line is up to 0.9 lb-in/1000 more conservative near 2250 lb) — this tool uses section 2.
Verified: the POH sample (Figure 6-5) is reproduced line by line — 1642 / 62.6, 180 / 8.6, 340 / 12.6, 340 / 24.8, 56 / 4.6, ramp 2558 / 113.2, −8.0 / −0.4, takeoff 2550 / 112.8 — with baggage area 1 at station 82: the printed 4.6 is 56 lb × 82 in, the forward end of the area, not the 95-in average arm (56 × 95 = 5.3). The tool states this rather than hiding it; with the 95-in arm the same loading gives 2550 / 113.6, also within limits.
- Cessna Model 172S Information Manual 172SIM incorporating the Pilot’s Operating Handbook and FAA Approved Airplane Flight Manual, Revision 5 (19 July 2004), P/N 172SPHUS05 — applies to Model 172S serials 172S8001 and on, conventional panel (not G1000); for training, not for flight planning of a specific airplane
- POH Section 2 Limitations — weight limits, center of gravity limits (normal and utility), baggage limits (pp. 2-7, 2-8), fuel limitations (p. 2-11) — FAA-approved limitation
- POH Section 6 Weight & Balance — Figure 6-3 Loading Arrangements (p. 6-9), Figure 6-5 Sample Loading Problem (p. 6-12), Figure 6-6 Loading Graph (p. 6-14), Figure 6-7 Center of Gravity Moment Envelope (p. 6-15), Figure 6-8 Center of Gravity Limits (p. 6-16)
- FAA Pilot’s Handbook of Aeronautical Knowledge, FAA-H-8083-25C (2023), ch. 10 Weight and Balance — weight × arm = moment, CG = total moment ÷ total weight, effect of fuel burn