- What happens if the CG is outside limits?
- An out-of-limits CG is a serious airworthiness issue. A forward CG can prevent rotation on takeoff or flare on landing. An aft CG can make the aircraft pitch-unstable or even unrecoverable from a stall. Do not fly outside published limits.
- Which Cessna 172 models are included and how do the presets differ?
- The calculator includes presets for the Cessna 172S/SP (2,550 lb max takeoff weight, 53 gal usable fuel), the 172R (2,450 lb, 53 gal), and the 172N (2,300 lb, 40 gal), plus the Cessna 150M. Each preset loads its own typical empty weight and arm, seat, fuel, and baggage stations, and the correct CG envelope, including the forward limit that tapers aft as weight increases.
- What is useful load and how do I calculate it?
- Useful load is max takeoff weight minus basic empty weight - everything you can load into the aircraft: pilot, passengers, fuel, and baggage. For example, a typical Cirrus SR22 with a 3,400 lb MTOW and a 2,250 lb empty weight has about 1,150 lb of useful load. Subtract full fuel (81 gal is roughly 486 lb at 6 lb/gal) to get the full-fuel payload.
- Can I use these presets for real-world flight planning?
- No. The preset numbers are approximate, typical POH values intended for flight simulation reference. Real aircraft vary by serial number, installed equipment, and modifications - for real-world planning always use the weight and balance data and CG envelope from your specific aircraft's POH and current weighing record.