How does the True Air Speed calculated in the aircraft?

Answer 1

Using the E6B flight computer..
TRUE AIRSPEED AND DENSITY ALTITUDE

1. Air density affects the indications of the airspeed indicator and the performance of the airplane.

1. Density altitude is the theoretical altitude in the standard atmosphere where the density is the same as the actual density you are experiencing in flight.

1. Density altitude is found by correcting pressure altitude for nonstandard temperature.

2. Pressure altitude can be determined by setting the airplane's altimeter to 29.92 and then reading the altitude.

1. If this is done in flight, make a note of the altimeter setting before turning it to 29.92.

2. After you determine the pressure altitude, reset the altimeter to the current setting.

3. The outside air temperature (OAT) can be determined by reading the current temperature on the airplane's OAT gauge.

1. You will need to use the Celsius scale.

2. True airspeed (TAS) is the actual speed of the airplane through the air.

1. TAS is found by correcting calibrated airspeed (CAS) for density altitude.

2. See your airplane's Pilot's Operating Handbook to determine CAS based on indicated airspeed.

1. Generally, there is little error at cruise speeds; i.e., CAS equals indicated airspeed (IAS).

2. Thus, as a practical matter, you may usually use IAS rather than CAS to determine true airspeed.

2. Determining True Airspeed and Density Altitude

1. True airspeed and density altitude can be calculated on the calculator side of your flight computer.

2. Rotate the inner scale until the numbers on the inner and outer scales match.

1. The window that is between "1:30" and "1:50" on the hour scale is labeled "DENSITY ALTITUDE" and the arrow points to the density altitude.

1. The numbers that rotate through this window are in thousands of feet and range from -10 (or -10,000 ft.) to 45 (or +45,000 ft.).

2. The window on the right side below "2:00" and "2:30" on the hour scale is used to set the OAT (above the window) over the pressure altitude (numbers in the window).

1. The OAT is in 5°C increments from +50°C on the left side to -70°C on the right side.

2. The numbers in the window are in thousands of feet and range from -2 (or -2,000 ft.) to 50 (or 50,000 ft.).

3. EXAMPLE: What is the TAS and density altitude if the IAS is 130 kt., OAT is -15°C, and the pressure altitude is 5,000 ft.?

1. Using the inner window on the right side, locate the OAT of -15°C and rotate the disk so the pressure altitude of 5,000 ft. (which is labeled "5" on the scale) is under -15°C, as shown in the figure.

2. In the window labeled "DENSITY ALTITUDE," read the density altitude of approximately 2,500 ft.

3. Locate the IAS of 130 kt., or "13," on the inner scale. Without moving the disk, read the TAS on the outer scale opposite the IAS, which is 135 kt

Answer 2

To calculate the true airspeed, the ratio of static and dynamic air pressure acting on the pitot and static ports on the aircraft is compensated for air compressibility, the air temperature and density at that particular altitude. With all these taken into account, the true air speed is obtained. Without any compensations, the ratio is merely an indicated airspeed. The calculations are done by the Air Data Computer.

Answer 3

A crude empirical formula for TAS =39*M*sqrt(T) where M is the Mach number of the craft and T is the static air tempertature in Kelvin (Degree celsius + 272 = Kelvin)

If temperature is not measured in the aircraft, you may use the value from International Standard Atmosphere for that altitude. If the aircraft doesnot have a machmeter, you will need to compute the mach number using speed of sound for the above mentioned temperature and dividing the IAS with this speed. This will be a crude estimate though!

Answer 4

It is determined by pitot pressure. A small tube with an open end pointed in the direction of flight leads a column of air into the air speed indicator where a bellows is expanded and movesa quadrant gear that rotates a shaft connected to a pointer that rotates in front of a calibrated dial.

Answer 5

usually, a reciprocating engine powered airplane (propeller) is constrained by potential of the engine ability in count of altitude - Thilem usually does not exist with jet airplanes, the place a lot of ability is accessible - whether, word that the optimal altitude is in many circumstances constrained by potential of the wht and the low buffet velocity of an airliner - Take the 747-2 hundred/3 hundred as an occasion - The 747 is certificated to fly as much as 40 5,one hundred feet - whether, to get it up there, it is going to be somewhat gentle, low payload, and gasoline tanks almost empty - while a 747-2 hundred/3 hundred is heavy (max gross weight is 833,000 lbs), it is form of able to climb to twenty-eight or 29,000 feet... attempting to fly any bigger could desire to in all probability get the airplane in a stall if maneuvers are mandatory or if there became into some turbulence - .

Answer 6

True airspeed is Indicated airspeed corrected for temperature and pressure. You can do a rough rule-of-thumb calculation by taking 1/2 your altitude in 100s of feet (same as FL #) and adding it to your indicated airspeed. For a more accurate conversion, use your E6B.

Answer 7

True Air Speed? An airplane is in an environment of air, independent of the earth below. You can calculate true air speed by timed reference of use on-board equipment that calculates the answer from radar or Doppler.

Answer 8

If you're talking about GA airplane, use your E6B. If you're talking about airliners, it's done by the onboard Air Data Computer (or something to the same extent). It receives all the data it needs, and shoots out the TAS on the EICAS.

Answer 9

True airspeed is the indicated airspeed (as read from the airspeed indicator), adjusted for
1. calibration errors
2. nonstandard altitude
3. nonstandard pressure

Answer 10

Senor Bostonian is on the money.

Time to change the vector, Victor.