This question will very obviously reveal that I am not a pilot :)In these days when we shall save energy and decrease smog. Why doesn't plane go straight on to target instead of following these SID/STARS roundabout way. I can understand the reason before GPS, but now when we have GPS. It should save huge cost.Georg

Well Georg, can you imagine if everybody on the ground drove their cars directly to their destination without paying any heed to roads, roundabouts, traffic lights etc, etc? Pandemonium!!Same thing applies to aircraft. They follow airways in order to insure traffic avoidance. SIDS and STARS are followed both to insure traffic avoidance and also to take into account such issues as terrain avoidance and noise abatement.As technology improves and aircraft become more electronically "aware" of other aircraft using the sky around them, there is the possibility in the future of more direct routings becoming available. For now though we all have to follow the motorways in the sky, stick to the speed limits and generally follow the "rules of the road".Hope this makes sense!Chris Kirk

The reason for SIDs/STARs is to seperate heavy traffic flowing inbound and outbound of big airports. If you fly into a second-tier or lower airports (probably 97% of airports) there are no SIDs or STARs so you can go straight to target (assuming VFR and no other 'obstacles'). If you are IFR you can still be going straight to target provided you are flying below the typical jet altitudes which are crowded. Cleveland controllers told me they are likely to allow direct-to provided you are cruising at those less frequented altitudes. So as you can see it is not so bad ...Michael J.http://www.reality-xp.com/community/nr/rsc/rxp-higher.jpg

Take a look at this report for an idea of the issues addressed in establishing a new STAR:http://www.mitrecaasd.org/library/tech_doc...01/mp01w060.pdf-michael