What is the use of calibrated airspeed / what speed creates flutter
I'm not working on ATPL theory, I've passed that several years ago.
As I'm a CRI now I think it's a good idea to check my knowledge.
I'm just considering subsonic flight here.
This is below what I understood, would anyone tell me if I got it right?
1a TAS is the true airspeed. I don't think TAS is of any use for the pilot. When we use TAS, it's because we want to know our ground speed. But TAS in itself will not help to fly the aircraft.
1b Nevertheless at high speed the TAS will cause the aircraft to flutter.
For small aircrafts the VNE/VNO are in IAS, meaning that at VNO, I'm closer to the risk of flutter at high altitude because my TAS is higher.
2 To fly the aircraft, the only useful speed is the EAS, as it's directly linked to the dynamic pressure, which is directly linked with lift and drag.
3a I don't see any use of the CAS. I think it has been invented only because it's easier to mesure than EAS, and that CAS is very close to EAS in the area of the flight enveloppe (low altitude low speed) where manoeuvres are required. But an ASI which would provide a best approximate of EAS instead of CAS would be better fit for purpose.
3b Is it a certification requirement that the IAS be the best approximate of the CAS, or is it permitted to design the IAS so that it indicates the best approximate of the EAS?