How fast can these planes go....??

[vertigo_blues]

I think you mean the same thing, but we usually use common aeronautical terms. Pitot tube measures total air pressure and static port picks up static air pressure. Dynamic pressure, which is directly taken as airspeed readings, is derived by substrating total pressure with static pressure, or in short differential pressure. In the early days of aviation when avionics doesn't exist, engineers simply use differential pressure gauges connected to pitot and static pressure lines.

However, the readings will only be considered as IAS or indicated airspeed, as it is not corrected for individual airframe aerodynamics. Manufacturers then calibrates the intrumentation errors and corrected it as CAS (Calibrated airspeed). But yet, it is still far from accurate.

The CAS will not be accurate as the airplane flies faster, due to the compressibility. In Bernoulli's theorem, fluid is considered imcompressible, but in practical world, it does and it's effect has to be considered. After correcting this, the airspeed will be refered as EAS(equivalent airspeed).

The final source of error is the changing air density at different altitude. At higher altitude where air density is so low, very little air actually rams into the pitot tube and the readings will be lower than the actual airspeed. After compensating for air density, the TAS(true airspeed) is finally being produced. Most modern aircraft now uses TAS as the reading will be corrrect at various kind of conditions.

Since airspeeds measure aircraft speed relative to both the winds and airflow over it, it will not be the same as ground speed. The fact that aircraft also travel in vertical profile also support this statement. Modern aircrafts use either inertial reference system or GPS to calculate ground speeds and drifts, and independent of the airspeed. The difference between the both speeds is the wind speed, and the amount of drifts shows its direction.

For model aircraft, when flying near or at sea level, the simple pitot-static system will be good enough. Above said is just for your reading pleasure and you can choose it ignore it. Have fun!

ICE-T :
Indicated airspeed corrected for position(Also known as Instrument error) error = Calibrated Airspeed.
Calibrated airspeed corrected for compressibility is called Equivalent Airspeed.
Equivalent Airspeed corrected for density is called True Airspeed.

The Eagle tree system should only be able to measure Calibrated Airspeed. Very little compressibility error at RC plane speed so thats why calibrated airspeed should be very very close to equivalent airspeed.
So at Mean sea level... Equivalent Airspeed is same as True Airspeed but if using Eagle tree pitot system at say 500' and above...it should be at a higher ground speed than indicated by the eagle tree system because the system does not correct to TAS....in order to correct that you will need a static port(To measure barometric) and also a temp sensor (To measure Air temperature) to compute it to TAS. TAS at Nil wind condition is ur ground speed. If there's 10 kts head wind..at 80 TAS then your ground speed(Actual speed will be 70Kts)...
Abit too technical haha...but i just wana to share with you guys.

[khatiban]

I think it is called the redshift analysis or something. They use the same theory to prove that the universe is expanding hence the big bang theory. Objects moving away from us will show more redshift in light and sound or something like that lol.

I heard about redshift b4. i think this term is used in astronomy where astronomers measure speed of a galaxy moving away/towards Earth. anyway, its all linked to Doppler effect
link here --> http://en.wikipedia.org/wiki/Doppler_effect

thats how Doppler radar was invented