Preliminary Endurance For Prop-Driven Aircraft Calculator

Endurance Formula:

\[ E = \frac{LD_{Emaxratio} \times \eta \times \ln\left(\frac{W_{L(beg)}}{W_{L,end}}\right)}{c \times V_{Emax}} \]

Lift to Drag Ratio at Maximum Endurance:

Propeller Efficiency:

Weight of Aircraft at Beginning of Loiter Phase:

Weight of Aircraft at End of Loiter Phase:

Power Specific Fuel Consumption:

kg/s/W

Velocity for Maximum Endurance:

m/s

Endurance of Aircraft:

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is the Preliminary Endurance for Prop-Driven Aircraft?

The Preliminary Endurance for Prop-Driven Aircraft calculates the maximum time an aircraft can remain in cruising flight. It is a crucial parameter in aircraft design and mission planning, especially for reconnaissance, surveillance, and patrol missions.

2. How Does the Calculator Work?

The calculator uses the endurance formula:

\[ E = \frac{LD_{Emaxratio} \times \eta \times \ln\left(\frac{W_{L(beg)}}{W_{L,end}}\right)}{c \times V_{Emax}} \]

Where:

\( E \) — Endurance of Aircraft (s)
\( LD_{Emaxratio} \) — Lift to Drag Ratio at Maximum Endurance
\( \eta \) — Propeller Efficiency
\( W_{L(beg)} \) — Weight of Aircraft at Beginning of Loiter Phase (kg)
\( W_{L,end} \) — Weight of Aircraft at End of Loiter Phase (kg)
\( c \) — Power Specific Fuel Consumption (kg/s/W)
\( V_{Emax} \) — Velocity for Maximum Endurance (m/s)

Explanation: The formula accounts for aerodynamic efficiency, propulsion efficiency, fuel consumption characteristics, and weight changes during flight to determine maximum endurance.

3. Importance of Endurance Calculation

Details: Accurate endurance calculation is crucial for mission planning, fuel management, and aircraft design optimization. It helps determine the maximum time an aircraft can remain on station or complete a specific mission profile.

4. Using the Calculator

Tips: Enter all required parameters with appropriate units. Ensure weight values are positive and beginning weight is greater than ending weight. All efficiency values should be between 0 and 1.

5. Frequently Asked Questions (FAQ)

Q1: What is the significance of lift to drag ratio in endurance calculation?
A: The lift to drag ratio represents the aerodynamic efficiency of the aircraft. Higher values indicate better efficiency and longer endurance.

Q2: How does propeller efficiency affect endurance?
A: Higher propeller efficiency means more effective conversion of engine power to thrust, resulting in better fuel economy and longer endurance.

Q3: Why is the natural logarithm used in the formula?
A: The natural logarithm accounts for the exponential relationship between fuel consumption and weight reduction during flight.

Q4: What is typical range for power specific fuel consumption?
A: Typical values range from 1.5×10⁻⁷ to 3.0×10⁻⁷ kg/s/W for modern aircraft engines, depending on engine type and operating conditions.

Q5: How does velocity affect maximum endurance?
A: There is an optimal velocity that maximizes endurance. Flying faster or slower than this optimal velocity reduces the total endurance time.