In the Rumour section /Linate thread Cedarbus outlines his company's procedures on lining up/cleared for take off. Transponder on....visual check....TCAS check.

I've no reason to doubt Cedarbus but does this mean that TCAS equipped planes are mobile Ground Radar Stations and that if all aircraft on ground/taxying had the transponders to ON rather than AUTO, this accident need not have happened ?

Are there difficuties in having Transponders ON at line up ? Is TCAS reliable at ground level ?

I ask this in ignorance and bewilderment and I did not raise this in the original thread cos I did not want to intrude on any professional discussions which might take place.

Grateful for any comments advice

:confused: