I have a question regarding speeds and what is read in the anemometer. Suppose an aeroplane is flying at 200 knots, the anemometer would read 200 knots. But now if we have a headwind of 20 knots, would the IAS (what is read in the anemometer) ready 180 knots or still 200 knots? Would the TAS be 180 knots which is the same as ground speed?
I know that the TAS would also take into account the instrument, position, density and compressibility errors but I want to get an example say at SL.
Thanks.