Exercise 2: Standard Atmosphere Airspeed The first part of this week's assignment is to choose and research an airport of interest. This can be an airfield near you or an interesting place you always wanted to explore further. The important thing is that it should have some regular weather reporting capability, in order to enable your research. For your research you can utilize the official FAA Airport/Facility Directory or any suitable and available online flight planning software, such as: http://www.aopa.org/airports/ or http://skyvector.com/airports (AOPA's flight planning tool has the advantage of directly depicting current weather as well). For weather information, you can use the official NOAA aviation weather from https://www.aviationweather.gov/metar or any other available flight planning tool - see AOPA link above. Notice that un-decoded METAR temperatures are usually given in C; however, if using the AOPA tool, the weather report will already be translated for you with temperatures in F and altimeter setting given by an A followed by four digits for the in Hg setting with two decimals. See picture below.) Field Elevation Temp in F ICAO Identifier Time This document was developed for online learning in ASCI 309: Aerodynamics File name: Ex_2_Std_Atm_Airspeed Updated: 06/16/2015 Altimeter Setting, i.e. 30.13 in Hg 1. Selected Airfield: 2. ICAO identifier (the ICAO identifier is the 4-letter airport code, starting with a 'K' for the continental US): 3. Field elevation [ft MSL] (field elevation can be found in the location information section at skyvector.com or the overview section at AOPA's flight planning tool): 4. Current weather report at the time of work on this assignment: a) Date and time: b) Current altimeter setting [in Hg]: c) Current temperature [F or C, but stay consistent]: When operating at an airfield within the US, the altimeter is adjusted according to current conditions (i.e. the reported altimeter setting that you found) in order to always indicate the correct field elevation when on the ground. Therefore, your indicated altitude will remain equal to your field elevation when being on the surface of that airfield, but your pressure altitude will be subject to change depending on changes in the altimeter setting. A. Using your researched data, find the Pressure Altitude of your airfield [ft]. Use the found altimeter setting and the rule of thumb lapse rate of 1 in Hg = 1000 ft, i.e. 00.01 in Hg = 10 ft change from the field elevation, with standard atmospheric altimeter setting being 29.92 in Hg (see also tutorial and example problems). Keep in mind that an increase in altimeter setting above standard will lead to a positive shift of Indicated Altitude above Pressure Altitude (or in other words, a lower pressure altitude than what is indicated) and vice versa. Note: In some cases (low field elevation, coupled with high altimeter setting) it may lead to negative pressure altitudes, which is completely correct. However, to allow further work in the atmospheric table excerpt in your textbook (Table 2.1, which does not include the negative values), you may change your altimeter setting in 4.b) to a lower value (please include a note) for all further work or select a different airfield (preferably above 1000' MSL). B. Based on your determined pressure altitude, find the Pressure Ratio, (delta), in the Standard Atmosphere Table (\"Flight Theory and Aerodynamics\