How the Flight Envelope Calculator Works
The Flight Envelope Calculator creates a simplified V-n diagram. A V-n diagram plots aircraft speed on the horizontal axis and load factor on the vertical axis.
The left side of the diagram is controlled by stall limits. The top and bottom are controlled by positive and negative load factor limits. The right side is controlled by cruise and dive speed limits.
Main Equations
Wing loading:
Stall speed at 1g:
Positive maneuvering speed:
The stall boundary is estimated using:
Example Calculation
Aircraft weight = 2400 lbf Wing area = 170 ft² CLmax = 1.5 Air density = 0.002377 slug/ft³ Positive load factor = 3.8 Negative load factor = -1.52 VC = 130 knots VD = 182 knots
The calculator converts all values consistently, calculates stall speed, maneuvering speed, and plots the simplified positive and negative load-factor envelope.
Important Limitations
Frequently Asked Questions
What is a V-n diagram?
A V-n diagram shows aircraft speed versus load factor. It helps visualize stall boundaries, maneuver limits, and speed limits.
What is maneuvering speed?
In this simplified model, maneuvering speed is where the positive stall boundary reaches the positive load factor limit.
Why is the old chart wrong?
The old chart used three speed labels but five load-factor values, so the plotted data points did not represent a valid envelope.
Can this calculator be used for real aircraft?
No. It is educational only. Use the approved aircraft flight manual, engineering analysis, and certification data for real aircraft.