KDR help?

[Mikezulu]

Hi guys some im finding it a bit difficult with these two questions, hoping someone could help me out as my course notes dont really help me with these questions.

12.74.4 With respect to the airspeed indicator, describe the:
(c) IAS/TAS/groundspeed relationship
and

2.12.4 State the limitations on pilots with regard to:
(a) unauthorised transmission (had a look through frto notes cant find anything on this)


any help is much appreciated.

[bentleg]

With respect to the airspeed indicator, describe the:
(c) IAS/TAS/groundspeed relationship

IAS - indicated air speed, is what you read on the dial of the ASI in the cockpit.

TAS - true airspeed, is the IAS corrected to ISA and ML conditions ie 1013.2 hpa and +15 deg C. When flying, if temperature increases above +15 , or air pressure decreases below 1013.2, the air is less dense, and the aircraft has to fly faster to hit the same number of molecues of air. TAS has these temperature and pressure variations taken into account. No allowance made for windspeed.

Ground Speed - is your actual speed over the ground - as seen in a GPS - in effect it, it is TAS adjusted by windspeed.

[djpil]

wot one reads off the air speed indicator is the airspeed indicator reading. The instrument is not 100% accurate but most pilots don't need to know that so you can take that as the IAS. i.e. If the instrument error is zero then ASIR = IAS.
Then the PE correction to get to CAS - pitot static pressure sensor errors which are nominally the same for a given type of aeroplane. The numbers are in the flight manual.
If you're going fast then there is the compressibility correction to get EAS.
And then density correction to get TAS.

So for small slow aeroplanes it is IAS - (flight manual PEC) - CAS/EAS - (whizz wheel) - TAS - GS.

Interesting that some older aeroplanes have limiting airspeeds marked on the ASI in CAS just to confuse us.

[Mikezulu]

sweet thanks man, helped alot :)