Previous Topic. 7mph (178km/h) at Sea Level. The formula for CAS is long and nested. 15 ≈ 0. This video is based on a mini-tutorial int. 5 deg C calculate the TAS. A pitot tube on the nose measures a pressure of 14. This expression is based on the form of Bernoulli’s. This handbook, AFFTC-TIH-81-5, AFM Standard Airspeed Calibration Procedures, was submitted under Job order Number SC6601 by the Comander, 6520 Test Group, Edwards APB, California 93523. Calculate the true airspeed and the calibrated airspeed. Follow. Highlight the true airspeed field. [In straight flight]: Assume that wind speed is fixed, calculate airspeed from wind speed, ground vector and heading. CAS = interp1( flaps0IAS, flaps0CAS, fltdata(:,4) ); The atmospheric properties, temperature (T), speed of sound (a), pressure (P), and density (rho), are determined at altitude for standard day using. The mechanics of airspeed control require managing three dynamic elements: power, pitch, and trim inputs. craft to a supersonic fighter are the pressure altitude,andthecalibrated airspeed. How to use the true airspeed calculator? Below are tips for using the true airspeed calculator and understanding how it works. Calculate the Mach number, true airspeed and calibrated airspeed at which the aircraft is flying. An ADC can determine the pressure altitude, vertical speed, calibrated airspeed, true airspeed (TAS), and density altitude (DA). If the localizer is swinging one way or the other, then make a 1-2 degree correction to avoid chasing. 31 CL_Max which is standard for a laminar flow wing. a. If you were solving a problem with an airspeed of 150 knots, the first calibration past 15 (150 in this case) would be 152. Description. In order to calculate ground speed, we must first have true airspeed and. In aviation, equivalent airspeed ( EAS) is calibrated airspeed (CAS) corrected for the compressibility of air at a non-trivial Mach number. Finally, the Calculate IAS subsystem uses the flap setting and calibrated airspeed to calculate indicated airspeed. The wind is from 030 at 12 knots and the true airspeed is 95 knots. which can be. Knowing your True Airspeed has other advantages as well. PLANNED TRUE AIRSPEED. What is an accurate expression to calculate IAS as a function of TAS? [duplicate] Ask Question Asked 4 years, 11 months ago. I am using two pressure sensors to measure altitude & airspeed via static /pitot lines. Use the atmoscoesa function to first calculate the speed of sound (sos) and static air pressure (P0). Find the Wind Wind is a problem during airspeed calibrations. 2. Calculate True Airspeed Given Indicated Altitude, Altimeter Setting, Temperature, and Indicated/Calibrated Airspeed. (Refer to Figure 22 on page 413. For groundspeed, true airspeed is adjusted for wind to achieve a value. IAN M. 14. To calculate the calibrated airspeed, you adjust the true airspeed for errors introduced through the pitot-static airspeed indicators used to determine airspeed. The indicated airspeed (IAS) from the flight and airspeed calibration table are used to determine the calibrated airspeed (CAS) for the flight. 00347 1 T 0 = 1 288. Please answer using this given info: density ratio = 0. For your planned cruise power setting and density altitude, determine the Calibrated Airspeed (CAS) and fuel burn rate in cruise. In aviation, equivalent airspeed ( EAS) is calibrated airspeed (CAS) corrected for the compressibility of air at a non-trivial Mach number. True airspeed is calibrated airspeed corrected for altitude and nonstandard temperature. 校準空速 （ Calibrated Air Speed ）也稱為 校正空速 ，為一航空術語，是在修正儀表誤差及位置误差後，在 空速表 （英语：airspeed indicator） 上顯示的 空速 ，其缩写形式为 (CAS)，用符号Vc表示。. The model's Display block shows both indicated and calibrated airspeeds. 77 deg R,. The spacing changes again at the number 30, where each calibration becomes . Since the majority of the time, planes fly at high altitudes, an equation is needed to calculate true airspeed, and this is best done using your mach number (M) with the equation:$egingroup$ @shortstheory Ahhh, it's only a slight difference in terminology, but Mach 0. . Calibrated airspeed is specific to the conditions in which the plane is flying, including altitude and temperature, as well as the shape of the aircraft wings. This is usually done with a flight calculator. KTAS (Knots True Airspeed) Airspeed corrected for changing atmospheric pressure at different altitudes. So: TAS = Mach * 38. In accordance to FAR 23. 0. 2 Air Data Information and Its Use 379 3. At a safe altitude, stall the airplane, look at the airspeed indicator, multiply its reading by 1. Boldmethod. Ground Speed (GS) The final type of speed that pilots use is ground speed (GS). To calculate the true airspeed of your aircraft, fly three separate legs, in rotation, at headings that differ by 90 degrees. At the same time, an incorrectly configured airspeed sensor can cause. Calibrated Airspeed (CAS) can be converted to True Airspeed (TAS) using the formula TAS = CAS / √ρ/ρ₀, where ρ is the air density at altitude and ρ₀ is the. The pilot reads an Indicated Airspeed (IAS) of 280. 2. To calculate a pressure altitude's actual height, you have to calculate the difference between the regional QNH and the 29. The calculation side. (Dynamic Pressure. By vector subtraction you can also calculate the wind vector (speed and direction) if you get a velocity. True airspeed is the reality. Indicated Airspeed. . The derivations of equations (1) and (2) are found in reference 1. At the model's position, the pressure coefficient is –0. 465 mps 4. 31 minutes. V S1 50 KIAS Stall speed or minimum steady flight speed in theAsk Question. When the air density or. Note the fine print. 43. 5. How to calculate calibrated Airspeed using E6B? To do this, you need to get Outside air temperature OAT from the metars, determine your True Airspeed from yo. Set this over the outside air temp, then look at your indicated airspeed and then look just outside of your indicated and there is the figure for true (corrected) airspeed. (Dynamic Pressure definition and formula can be reviewed in “Flight Theory and Aerodynamics” page 30 (EQ 2. The aircraft manufacturer provides tables to find the CAS from the IAS read on the airspeed indicator. The Electronic E6B, once understoo. You can set the true airspeed in the True Airspeed block in the model. At any other altitude, equivalent airspeed will be. Look for the letters ‘CAS’ for calibrated airspeed and ‘TAS’ for true airspeed. How to convert knots to mph formula. g. Airbus A330. The pitot probe mounted on the aircraft measures a pressure of. Definition Calibrated Airspeed (CAS) corrected for altitude and non-standard temperature - the speed of the aircraft relative to the. This is the point of your cross-country p. 4. Beechcraft Super King Air: P0 - P∞ = 5482 N/m^2. Dependencies. Airspeed: This is the speed of the aircraft relative to the air mass through which it is flying. Keep a coordinated turn (ball centered). Indicated / Calibrated Air Speed : True Air Speed (TAS) : Pressure Altitude (ft): Density Altitude (ft): E6B, NavLog Calculator, Weather Reports, METAR, TAF, Wind. The IAS is typically used for low speeds and low altitudes. 2 and would be read as 15. 50 lbs/ft2, T = 411. 2, 15. If the ambient air temperature is 230 K. Within the airspeed indicator, there is a certain amount of trapped air. Groundspeed is the speed of the aircraft in relation to the ground. Let's say your CAS is 120 knots. • This technique can be applied to most of the other V speeds. Indicated airspeed (IAS) is what you read off the airspeed indicator as you fly. After simulating the. Why is Mach number used to measure airspeed? E6B, NavLog Calculator, Weather Reports, METAR, TAF, Wind Components, Instrument Simulator, Weight and Balance, Pressure Altitude, Density Altitude, True Air Speed. This calculator is designed to give a corrected value known as TAS, or true airspeed. Modern aircraft instrumentation use an Air Data Computer to perform this calculation in real time and display the TAS/Mach reading directly on the Electronic Flight Instrument. Assume incompressible flow. com or. Jun 13, 2016. The formula for calculating True Airspeed (TAS) from Indicated Airspeed (IAS) is TAS = IAS + (IAS * (pressure altitude / 1,000) * 2%). 4 for diatomic gases Δ p = Dynamic pressure/pressure. What you should do is then bug this heading and see how it's working for you. Assume R = 287. C. This example shows the differences between corrected airspeeds and true airspeed (TAS). 16 4576. A properly configured airspeed sensor can greatly improve the ability of Plane to maintain altitude in auto-throttle modes (such as AUTO, CRUISE and FBWB), as well as greatly improve automatic landing. It will compute the true airspeed in knots and Mach number and density altitude, given the pressure altitude, temperature, and calibrated airspeed in knots. Airspeed is measured in knots (nautical miles per hour) or in some cases, miles per hour (mph) or kilometers per hour (km/h). Add 2 minutes for climb-out. This example shows the differences between corrected airspeeds and true airspeed (TAS). True airspeed is calibrated airspeed corrected for altitude and temperature. View example;True Airspeed – TAS – Depending on the temperature and the altitude at which you are flying, the air is less dense than at sea level during standard conditions. Before you read aGround Speed GS - TAS further corrected for wind Indicated to Calibrated POH 5-10 Calibrated to True Airspeed E6B Course and Heading True vs Globe Heading vs Course TC +/- WCA = TH, E6B TH +/- VAR = MH, Isogonic lines (Dashed Magenta line, East least, West is best) MH +/- Dev = Corr. Interestingly, the load factor incurred by abruptly pulling back on the yoke at a particular airspeed turns out to depend only on V S. How to calculate calibrated Airspeed using E6B? To do this, you need to get Outside air temperature OAT from the metars, determine your True Airspeed from yo. 2GPH = 7. e. Airspeed indicator itself. Calibrated airspeed is more accurate than indicated airspeed because it includes additional variables that affect the true airspeed of the aircraft. Use the atmoscoesa function to first calculate the speed of sound ( sos) and. In this exa ple, press ure al ti de is 10,000 feet, tempera ure is 2°C, and CAS is 200 knots. To calculate True Airspeed (TAS) from Mach number, you can use the formula TAS = Mach × √ (γ × R × T₀), where γ is the specific heat ratio, R is the gas constant, and T₀ is the standard sea-level temperature in Kelvin. 00347. An aircraft can move faster when the air is thinner, but this won’t appear on the airspeed indicator, because when the air is thinner, so is the air entering the pitot tube. Airspeed indicator in aircraft is scaled in miles per hour. . It implicitly includes air density and thus altitude). (Of course, knowing p0 and M, we could compute equivalent airspeed, but convention may still force us to deal with calibrated airspeed. com) On one hand the probe, depending on its location, could measure the pressure in the free stream, in the high velocity stream, or in the low velocity stream. Calculate the Mach number at which the airplane is flying. AERODYNAMICS 1 PREPARED BY: ENGR. A high-speed subsonic McDonnell Douglas DC-10 airliner is flying at a pressure altitude of 10 km. Collect flight data on 3 legs 90 degrees apart. atmosphere: input altitude to compute 1993 International Standard Atmosphere data. Calculate the Calibrated Airspeed. TAS is the airplane’s speed through the air, relative to the air. Flight data was. A pitot-tube at its wingtip measures a pressure of 4. This calculator estimates the calibrated airspeed (KCAS) of a helicopter. TAS Calculator True-Air-Speed Calculator: Indicated Altitude: feet: meters: Altimeter Setting: inches: hPa: Temperature: °C °F: Indicated/Calibrated Airspeed: (KTS or MPH) True Airspeed (TAS): Density Altitude (DA): Pressure Altitude (PA):Calibrated Airspeed gradually deviates from True Airspeed as altitude increases. Know the difference between indicated, equivalent, calibrated, and true airspeeds. Note you should generally expect TAS to be greater tha. TAS is given in mph. KCAS (Knots Calibrated Airspeed) Like KIAS, but corrected for instrumentational or positional errors. Troubleshooting these errors is notoriously difficult. Use constant-airspeed climbs for a cruise climb or on climbout to maintain best rate of climb (VY) or best angle of climb (VX) speeds. 3) For this subquestion, assume the aircraft is flying at a CL of 0. It consists of a tube placed parallel to the flow and open to the flow at the endpoint (A). You can calculate true airspeed by entering calibrated airspeed, pressure altitude, and temperature into a flight computer. Obtaining CAS from IAS. 3) Groundspeed (GS) The movement of your airplane relative to the ground is called groundspeed. Once the test data is collected, the ADCs are calibrated so that the indications seen by the pilot in the cockpit are free of these errors. Because of the lower air density at high altitudes, the airspeed indicator reads lower than it would at the same speed down at a lower altitude. K and k = 1. Press "Eval on the remaining field which is equivalent airspeed. When seeing this question there is only one thing is coming up to my mind and which is: Temperature drops 2° C every 1000 ft but I cannot connect the dots to find TAS. If the ambient air temperature is 230 K, calculate the true airspeed and the calibrated airspeed. A cylinder that is 2′ in diameter and 5′ long is spinning at 100 revolutions per sec in an airstream that has calibrated airspeed in a standard atmosphere at sea level. In the aeroblk_calibrated model, the aircraft is defined to be traveling at a constant speed of 70 knots (indicated airspeed) and altitude of 500 feet. An aneroid instrument, the airspeed indicator measures the dynamic pressure of the outside air entering a pitot tube. In still air, the TAS is equal to the groundspeed. An experimental rocket powered aircraft is flying with a velocity of 3000 mph at an altitude where the ambient pressure and temperature are. A Pitot tube on the wing tip measures pressure of 4. It is a device for measuring forward speed of an aircraft. Here are three book definitions. 51 x 104 N/m2 . That's because your airspeed indicator reports a slower speed than true airspeed as density decreases, based on altitude and air temperature changes. Groundspeed is true airspeed corrected for wind. Calculators. "An extension of this idea is to fly three legs at the same altitude and airspeed. For example, the knots multiplied by 1. Find the True Lift-Off Speed [KTAS]. 3. Calculate True Airspeed (TAS) in knots and m/s, Mach number, and Calibrated Airspeed (CAS) in knots and m/s. 7. For ease. The knowlegde of pressure permits the calculation of the airspeed provided that the instrument in use is properly calibrated. The following will calculate three speeds based on the altitude and entered fourth speed - e. The calibrated airspeed takes the aircraft specific known value of the calibrated airspeed offset for each aircraft and applies it to the indicated airspeed reading. On older aircraft, airspeed is usually indicated to the pilot on a graduated scale over which a pointer moves ( the first diagram). (No flaps, level flight) That's Wing Lift Coefficient of 1. That speed is used for performance related airspeeds such as stall speed, minimum control speed, V1, VR, V2,. . One might think the airspeed indicator is calibrated by simply reversing the well-known formula (from Bernoulli) for static pressure, namely: q = 1 2ρv2, like this: vIAS. Calculate the Dynamic Pressure ‘q’ [lb/ft2], based on the TAS above; make sure to use a formula consistent with a Lift-Off Speed in kts. Your POH usually lists a bunch of power settings and the TAS and fuel burn for each one. This example shows the differences between corrected airspeeds and true airspeed (TAS). Finally, the Calculate IAS subsystem uses the flap setting and calibrated airspeed to calculate indicated airspeed. The CAS is calculated based on the indicated airspeed and the airspeed calibration data, which are provided by the manufacturer or the operator. Within the realm of Aeronautical Engineering and Aviation, True Airspeed (TAS) plays a pivotal role. Using the wind noise as an input to the airspeed calculation is a great idea (but it will probably have to be calibrated for each glider separately, and periodic re-calibration will be needed as gliders get noisier with age). KTAS is true airspeed given in knots. What is the difference between calibrated and true airspeed? Calibrated Airspeed (CAS) is the indicated airspeed corrected for instrument and position errors. True Airspeed is Calibrated Airspeed corrected for nonstandard temperature and pressure. Transitioning from knots to Mach . In low-speed flight, it is the speed. What is the formula for TAS and ground speed? Ground Speed (GS) is different from TAS and is calculated by considering the aircraft’s TAS and the. Calibrated airspeed is indicated airspeed adjusted for a variety of errors. True airspeed is the airspeed that we would read ideally (and the airspeed value easily calculated within a simulation). BoeingThe altimeter is calibrated to show the pressure directly as an altitude above mean sea level, in accordance with a mathematical model defined by the International Standard Atmosphere (ISA). Part 23, §23. IAS figures in aircraft manuals are actually converted from CAS. 0065 K/m (Kelvin per meter); h: Altitude above Mean Sea Level (MSL) (meters); Tc: OAT Estimation Correction (Kelvin); Impact on Society. What Calibrated airspeed would you need to fly at in order to maintain a true airspeed of 150kts at 11,000’ MSL with a temp of 6°C How would you calculate necessary CAS in order to maintain a certain TAS, completely by hand?. Thats the quick formula for true airspeed. Outside air temperature (OAT): -15° C. To calculate airspeed, we convert the pressure of air that is. In the aeroblk_calibrated model, the aircraft is defined to be traveling at a constant speed of 70 knots (indicated airspeed) and altitude of 500 feet. MACH NUMBER (M) “P ratio – Mach Number relationship”. K: The instrument calibration factor of the airplane . What is the indicated air speed and the true air speed of the airplane in. 1. (FLASHING) T 232. To calculate True Air Temperature (T) use T= IAT-ΔT. The airspeed indicator (ASI) or airspeed gauge is a flight instrument indicating the airspeed of an aircraft in kilometres per hour (km/h), knots (kn), miles per hour (MPH) and/or metres per second (m/s). The errors are most pronounced in slow and high angle-of-attack flight. The sleek Grob 115, for example, has less drag per horsepower than a Pitts Special, which. Then I would go into the FLT menu on the CX-3, and select Airspeed, and I would input all the values that you have, such as OAT, pressure altitude, and now CAS (calibrated airspeed) 0 Votes. 27 minutes. In the aeroblk_calibrated model, the aircraft is defined to be traveling at a constant speed of 70 knots (indicated airspeed) and altitude of 500 feet. The ASI measures the pressure differential between. But when you put the arithmetic to the question the conundrum seems a bit more clearly understood. Table Lookup (Default) Generate output airspeed by looking up or estimating table values based on block inputs. CAS: Calibrated Air Speed (reference airspeed based on an idealized Pitot tube)for which many people asserted that I need a pitot tube and a static port in order to calculate airspeed and pressure altitude respectively, and errors will build up if I just integrate the accelerometer values from the IMU. 54 5162. There is an aerodynamic instrument that actually measures the total pressure at a point in the. V-Speed Symbol Speed Value What Is It? V SO 44 KIAS Stall speed or minimum steady flight speed in the landing configuration (flaps fully extended). If On, the aircraftUse this tool to calculate the Pressure and Density Altitude from airfield elevation, the local QNH , the Outside Air Temperature and the Dew Point. Next Topic. Finally, the Calculate IAS subsystem uses the flap setting and calibrated airspeed to calculate indicated airspeed. IAS is the airspeed read directly from the aircraft’s airspeed indicator. Calibrated airspeed is defined as the indicated airspeed corrected for instrumentation errors in the pitot-static pressure measurement system. It is also the airspeed at sea level in the International Standard Atmosphere at which the dynamic pressure is the same as the dynamic pressure at the true airspeed and altitude at which the aircraft is flying. 2 Answers. It is also the airspeed at sea level in the International Standard Atmosphere at which the dynamic pressure is the same as the dynamic pressure at the true airspeed (TAS) and altitude. (Compressibility Correction Chart, see “Flight Theory and Aerodynamics”, Fig. Calibrated airspeed is equivalent airspeed modified with compressibility effects of air, which affect the airspeed indicator. It’s the speed at which you move through the air, and it increases as altitude increases. 20 1144. What Calibrated airspeed would you need to fly at in order to maintain a true airspeed of 150kts at 11,000’ MSL with a temp of 6°C How would you calculate necessary CAS in order to maintain a certain TAS, completely by hand? Not allowed to screenshot or use the exact question. In the aeroblk_calibrated model, the aircraft is defined to be traveling at a constant speed of 70 knots (indicated airspeed) and altitude of 500 feet. Using your flight computer, calculate the cruise density altitude. All cross country aviation calculations are based on flying at the planned true airspeed, generally defines as the speed of the airplane through the relatively undisturbed airmass. Take your pick. The corrected airspeeds are indicated airspeed (IAS), calibrated airspeed (CAS), and equivalent airspeed (EAS). You do this using an E6B. At sea level under ISA conditions, equivalent airspeed and calibrated airspeed are the same. 10) The correction form EAS to True Airspeed (TAS) is dependent upon: density ratio alone 11) An airplane operating an airfield which has a barometric pressure of 27. The model's Display block shows both indicated and calibrated airspeeds. Equivalent airspeed is calibrated airspeed corrected for the compressibility of air at a non-trivial Mach number. CAS is another type of airspeed used in aviation, and it is not corrected for wind effects like ground speed. Problem is, I don't have a Mach number to solve the equation. Description. 967854*SQRT(OAT+273. 若是在高速、高海拔的條件下，校準空速還需要修正由於空氣可壓縮性. J. - ratio of the speed of a body to the speed of sound in the surrounding medium. The IAS is typically used for low speeds and low altitudes. . 15 ≈ 0. EAS is equivalent airspeed. 149, Minimum Control Airspeed (Vmc) is the calibrated airspeed at which a multi-engine aircraft should fly when there is loss of a critical engine. The climb models for constant equivalent/calibrated airspeed as well as constant climb rate climbs introduce the flight path angle correction factor as a function of altitude, airspeed,Fig. 1. TAS is true airspeed. Now calculate the calibrated airspeed (ft/s, m/s, and kt) using equation 3. The TAS, or even better, ground speed, is needed primarily for navigation, but not for flying per se. 0 kts. 00:21. Find out what your turn radius is at cruise airspeed up high and at approach airspeed down lower; find out what a 1° pitch change will do to your VVI and remember those numbers; The 60-to-1 Rule:In this short tutorial I will show you how to calculate the true airspeed from the equivalent airspeed. Procedure: 1. I've had a look at wikipedia and to calculate OAT, the total air temperature is required. Add the outcome to your indicated air speed (IAS)Calibrated Airspeed gradually deviates from True Airspeed as altitude increases. Be able to calculate the true airspeed of. Although the original author of the formula is not precisely. True airspeed (TAS) is the speed at which an airplane is moving relative to the air that surrounds it. [2] This is the pilots' primary airspeed reference. The Navigation Computer: Airspeed Indicator Errors - Application of Corrections. TAS is true airspeed. Calibrated airspeed is defined as the indicated airspeed corrected for instrumentation errors in the pitot-static pressure measurement system. Among the common conventions for qualifying airspeed are: indicated airspeed ("IAS"), calibrated airspeed ("CAS"), true airspeed ("TAS"), equivalent airspeed ("EAS") and density airspeed. Set the power. For instance, if the Airspeed Indicator Needle is pointing to 85 knots, then the Indicated Airspeed (IAS) would obviously be 85 knots. If the ambient air temperature is 300 K, calculate the true airspeed and the calibrated airspeed. 15) where OAT is expressed in degrees Celsius. A7-4. BROWN Aircraft Performance Engineer SEPTEMBER 2012 TECHNICAL INFORMATION HANDBOOK AFFTC-TIH-10-01 Approved for public release; distribution is unlimited. 8 Gal/100NM. Calculate the required thrust per engine in kN. To calculate the calibrated airspeed, you adjust the true airspeed for errors introduced through the pitot-static airspeed indicators used to determine airspeed. Calculate the Mach number at which the airplane is flying. If you shot a police radar gun at a plane flying by, you'd be measuring groundspeed of the airplane. If the ambient air temperature is 300 K, calculate the true airspeed and the calibrated airspeed. TAS, unlike Indicated Airspeed (IAS), accounts for changes in atmospheric density and temperature, giving pilots a more accurate measure of their speed relative to the air around them. 4. S. Set those values in the window. Airspeed is typically measured using a pressure differential device called a pitot tube, and therefore is susceptible to variation at different altitudes. Set 29. The calculation side. 3. just look in the POH and see if the prominent airspeed limitations such as Vne/Vmo are shown as IAS or CAS on the airspeed tape. Problem 5: A high-speed subsonic aircraft is flying at a pressure altitude of 10 km where the ambient temperature. . Once you have the indicated airspeed reading, you must convert. It’s n=V 2 / V S 2, where V is the calibrated airspeed at the start of the maneuver. 5, and we would like to increase that by 2 to 38. This chart allows a pilot to correct for the discrepancies and calculate the calibrated airspeed (CAS). The true airspeed (TAS) can be calculated from the indicated airspeed (IAS), which is derived from the pitot tubes and static ports, as follows: TAS = IAS ρ0 ρ(a)− −−−√, T A S = I A S ρ 0 ρ ( a), where ρ0 ρ 0 is the air density at sea level and ρ(a) ρ ( a) the air density at altitude a a, which depends on pressure P P and. Simply enter the figure into the calculator, and you'll have the response in mph, ft/s, m/s, and km/h in the blink of an. To calculate the calibrated airspeed, you adjust the true airspeed for errors introduced through the pitot-static airspeed indicators used to determine airspeed. At the most basic level the Mach formula is: Mach = TAS/Speed of Sound The speed of sound is a slightly non-linear function of temperature: 38. True Airspeed (TAS) is the actual speed of the aircraft through the air corrected for altitude and temperature. Calculate the Mach number at which the airplane is flying. For standard sea-level conditions, calibrated airspeed is equal to true airspeed. Working on programming my own E6B and am stuck trying to calculate the following problem from Sporty's E6B: Given wind info and desired speed/course, what. For example, several type air-6. CX3. The A scale is on the outside of the instrument. Or, if you are unfamiliar with trigonometry (using Pythagora's theorem): v G S = v T A S 2 − v v e r t i c a. Groundspeed is the speed of the aircraft in relation to the ground. • Calibrated airspeed - The reason for the importance of calibrated airspeed information is that it provides a direct measure of the impact pressure, by definition, and the impact pressure together with the angle of incidence determine the aerodynamically generated lift and drag forces and moments acting on the aircraft. What you see on the dial, is the IAS. Equivalent airspeed is calibrated airspeed with compressibility effects of air which affect the airspeed indicator removed. Groundspeed is the speed the aircraft is crossing over the ground at. I found a lot of rules of thumb. To descend, decrease power.