File talk:Asiana Flight 214 Approach to SFO.png

Symbols don't appear to match the legend. Airspeed and altitude symbols now use the same symbols for the crash date.— Preceding unsigned comment added by 118.208.156.103 (talk) 10:20, 14 July 2013‎ (UTC)[reply]

Corrected. Airspeed for July 6 is a horizontal bowtie, altitude a vertical bowtie. Apteva (talk) 16:06, 16 July 2013 (UTC)[reply]

units[edit]

Why can't you just use "knots" and "feet" (spelled out in lowercase) or "kt" and "ft" (standard abbreviations)? "Kts" clearly is not a standard abbreviation. 75.210.152.163 (talk) 17:10, 22 July 2013 (UTC)[reply]

data source[edit]

What is the source of these data? I am suspicious of the generic label "altitude" when the data might actually be (uncorrected) pressure altitudes. Using uncorrected altitudes necessarily introduces differences between the descent profiles. Clearly the altitude of the main landing gear was less than 13' at some distance from the runway threshold. The final data point appears to be around 100' altitude which is too high to collide with anything. 75.210.138.66 (talk) 08:35, 23 July 2013 (UTC)[reply]

All of the data is rounded to the nearest 100 feet, so being concerned about 13 feet is moot. The final data point was reported at 100 feet, but could have been 149 feet (and where on an aircraft with a fuselage that has a diameter of 20 feet is that?). It was reported about 5 seconds prior to impact with an indicated rate of descent of 1140 feet/minute. At that rate it would be 95 feet lower at impact. 11 seconds before that the rate of descent was reported to be 840 feet/minute (154 feet in 11 seconds) and the altitude 300 feet. None of the data should be looked at as being very precise, but gives a good comparison with the flights that landed successfully. Apteva (talk) 04:05, 25 July 2013 (UTC)[reply]

That doesn't account for the the fact that the chart will show identical descent profiles differently on different days because it uses uncorrected pressure altitudes. 71.60.50.60 (talk) 19:50, 28 July 2013 (UTC)[reply]

These are not pressure altitudes. "In aviation, pressure altitude is the indicated altitude when an altimeter is set to an agreed baseline pressure setting. The baseline pressure is 1013.25 hPa, equivalent to 1013.25 millibar, or 29.92 inches of mercury." Aircraft pilots dial in the local pressure so that they will know how high they are above the runway. Using a different pressure setting, or the pressure altitude, would not change the slope of the lines, but would move them up or down a uniform distance. Pressure altitudes are used enroute (above a certain altitude), but not on take-off or landing. Apteva (talk) 02:16, 29 July 2013 (UTC)[reply]

From the FlightAware FAQ: "Altitudes displayed are the airplane's altitude above sea level (MSL) and disregard the elevation below." Apteva (talk) 05:07, 30 July 2013 (UTC)[reply]

The table in the link given as source lists groundspeeds, but the graph labels them as airspeeds. Shouldn't this be corrected, or am I missing something? JaneStillman (talk) 23:24, 7 August 2013 (UTC)[reply]