OU Aviation Training Series - True Airspeed on ASI
Why Aviation Stack Exchange recommends it
Aviation Stack Exchange answerers link it as a visual demo of how a steam-gauge airspeed indicator converts indicated airspeed to true airspeed using pressure altitude and outside air temperature.
Recommended by 1 people across 1 different months, 2016 to 2019.
What it is
A short training video from the University of Oklahoma aviation program showing how to read true airspeed from an airspeed indicator that has a built-in sliding temperature and altitude compensation scale. It is a quick demonstration of the dial mechanics aimed at student pilots.
What people said
Recommends voretaq7 · 2016-02 · Aviation Stack Exchange · on “How does a true airspeed indicator work?”
For a basic True Airspeed Indicator (TAS Meter) like the one shown below, you simply dial your pressure altitude into the top window using the knob (aligning it with the appropriate temperature mark at the bottom of that window), and then read your true airspeed in the other window at the bottom. [LINK] Your pressure altitude can be obtained by setting your altimeter to 29.92 and reading the indication, the air temperature can be obtained from an outside air temperature (OAT) gauge (or you can use one from the Winds Aloft forecast if your aircraft does not have an OAT gauge), and the combination of the two gives you your density altitude. The meter itself is simply a mechanical slide rule, p
Cites mins · 2016-06 · Aviation Stack Exchange · on “What are the landing stall speeds of a Cessna 172?”
Yes, the 6 o'clock sector shows the TAS (there is a legend `TAS` close to the small ruler). It corrects for the OAT/Pressure combination the pilot selects in the 12 o'clock sector, labeled `Temp°C` and `Press Alt`. See a demo video [this video] . Density is assumed from pressure and standard atmosphere model. Only cruise speeds are converted, as this is where you are supposed to be in altitude and in need of TAS.
Cites Dave · 2019-02 · Aviation Stack Exchange · on “Temperature sensor are needed to compute True Airspeed for low speed aircrafts?”
A good chunk of aircraft operating in the <100Kt range generally don't have Air Data Computers although glass cockpits are becoming more and more common in general aviation aircraft. For good old steam gauges a sliding temperature compensation scale is built right into the Air Speed Indicator, for more info on that see this question [LINK] or this video [this video] . OAT is determined generally by a thermometer installed on the windscreen or in the side window. [LINK] If your aircraft is equipped with with a capable glass cockpit you may be able to get TAS from the system [LINK] The Airspeed Indicator displays airspeed on a rolling number gauge using a moving tape. The true airspeed (TAS) is dis