TruAirspeed vs FlightCALC

TruAirspeed is a True Airspeed Calculator for the iPhone and iPad. It's a bit different from other true airspeed calculators, in which the pressure altitude is an input. This requires resetting the altimeter to the standard sea level pressure of 29.92"Hg to read the pressure altitude. With TruAirspeed, you input the indicated altitude and the Kollsman window's pressure setting — the app then calculates the pressure altitude, density altitude, true airspeed and mach number for you. The calculations involved take full account of compressibility effects, but not shock waves, so it's limited to subsonic, non-transonic flight only. You have a choice of units for inputs and results, and you may choose either a calculator-style keypad (top row: 7-8-9) or a telephone-style keypad (top row: 1-2-3). You may also set a correction factor for your bird's airspeed indicator/pitot-static system, if you know it (mine is 0.95).

FlightCALC can be used for altitude, speed, temperature, wind and turn calculations and even contains supersonic and stratosphere flights. Calculation of bank, radius and acceleration are unique. Various wind computations are implemented. Brightness control for use from dawn to dusk and in addition right- and left-handed keypad orientation available. HOW TO USE FlightCALC: Calculation: • touch a highlighted field and insert value • insert as many value as known • the inserted values are blue colored • touch CALC and FlightCALC will compute as many values as possible in black • touch a blue value and change it for a new calculation Conversion: • QNH pressure from hPa into inHG and vv. • temperature from centigrade to Fahrenheit and vv. • feet to meters and vv.