To calculate the True Airspeed (TAS), we need to convert the indicated airspeed (IAS) to equivalent airspeed (EAS) and then to true airspeed (TAS). The formula for calculating TAS is:
TAS = EAS * √(ρ/ρ0)
Where:
EAS = IAS * √(ρ0/ρ)
ρ0 = standard air density at sea level = 1.225 kg/m³
ρ = actual air density at flight level 280
To calculate ρ, we can use the formula:
ρ = ρ0 * h/288.15
Where:
h = height above sea level = 28000 ft = 8534.4 m
Let's calculate ρ first:
ρ = 1.225 * (8534.4/288.15) = 2.849 kg/m³
Now let's calculate EAS:
EAS = 290.0 * √(1.225/2.849) = 249.32 kts
Finally, let's calculate TAS:
TAS = 249.32 * √(2.849/1.225) = 276.17 kts
The True Airspeed (TAS) is 276.17 kts.
Now, let's calculate the required lift coefficient:
Lift coefficient (CL) is given by the formula:
CL = 2 * weight / (ρ * TAS^2 * wing area)
Assuming the weight of the Airbus A380 is 1.2 million kg and the wing area is 845 m²:
CL = 2 * 1.2e6 / (2.849 * (276.17)^2 * 845) = 0.1204
The required lift coefficient (CL) is 0.1204.
Finally, let's calculate the available power per engine in MW:
Assuming the aircraft is flying at a CL of 0.52 and at a True Airspeed (TAS) of 250 m/s:
The available power per engine (P) can be calculated using the formula:
P = (CL * ρ * TAS^3 * wing area) / (2 * η)
Assuming the wing area is 845 m² and the engine efficiency (η) is 0.85:
P = (0.52 * 2.849 * (250)^3 * 845) / (2 * 0.85) = 18,875,983.52 W = 18.88 MW
The available power per engine is 18.88 MW.
An Airbus A380 is flying in steady, horizontal flight at Flight Level 280.
The pilot reads an Indicated Airspeed (IAS) of 290.0 kts. Calculate the True Airspeed (TAS) in kts
Calculate the required Lift Coefficient
For this subquestion, assume the aircraft is flying at a CL of 0.52 and at a True Airspeed of 250 m/s (which are not the correct answers to the previous questions). Calculate the available power per engine in MW.
1 answer