# Helicopter Flight Paths **URL:** \ **Category:** Factual Questions\ **Created:** [June 17, 2014, 12:05am UTC](https://boards.straightdope.com/t/helicopter-flight-paths/690946 "2014-06-17T00:05:28Z")\ **Posts on this page:** 5\ **Page:** 2
**Author:** ![Shagnasty](https://avatars.discourse-cdn.com/v4/letter/s/9dc877/32.png) [@Shagnasty](https://boards.straightdope.com/u/Shagnasty)\ **Post date:** [June 17, 2014, 11:00pm UTC](https://boards.straightdope.com/t/helicopter-flight-paths/690946/21 "2014-06-17T23:00:36Z")
> [@md2000](#): > > I always heard of controlled airspace better described as an upside-down wedding cake - radius expands at certain intervals. That is a better analogy for airspace but I have found that not everyone knows what a typical wedding cake looks like or has trouble visualizing it upside down without a diagram so I tend to say it is like an ice cream cone because everyone can visualize that even if it isn’t quite as accurate. I figure, the general concept is more important than the exact details. They will need to figure out a whole lot more about airspace than that if they ever get their pilot’s license anyway. ---
**Author:** ![PaulParkhead](https://avatars.discourse-cdn.com/v4/letter/p/7ea924/32.png) [@PaulParkhead](https://boards.straightdope.com/u/PaulParkhead)\ **Post date:** [June 17, 2014, 11:01pm UTC](https://boards.straightdope.com/t/helicopter-flight-paths/690946/22 "2014-06-17T23:01:05Z")
> [@Asimovian](#): > > My recollection (from a very, VERY limited exposure to flying lessons, so I apologize if this is inaccurate) is that private aircraft CAN be outfitted with a couple of different systems that alert you to other aircraft in the area, but that those other aircraft also have to be using the same system in order to be identified, so it wasn’t the same thing as having radar. Sounds like you’re thinking of a [TCAS](http://en.wikipedia.org/wiki/TCAS), perhaps? You’re right: they can be fitted to smaller aircraft, but there are plenty flying that don’t have them. ---
**Author:** ![Asimovian](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asimovian/32/172_2.png) [@Asimovian](https://boards.straightdope.com/u/Asimovian)\ **Post date:** [June 17, 2014, 11:08pm UTC](https://boards.straightdope.com/t/helicopter-flight-paths/690946/23 "2014-06-17T23:08:12Z")
> [@Shagnasty](#): > > Right. There are a number of different types of Traffic Advisory and Collision Avoidance systems for aircraft both large and small but they are uncommon on smaller planes partly because of the high cost and most of them don’t use radar at all. Some of them just use a passive strategy to intercept transponder returns from initiated by more sophisticated equipment located elsewhere so they can’t always give a complete picture of all possible traffic. They are a supplement to a pilot’s own eyes and ATC but they do not replace it in any way. > [@PaulParkhead](#): > > Sounds like you’re thinking of a [TCAS](http://en.wikipedia.org/wiki/TCAS), perhaps? You’re right: they can be fitted to smaller aircraft, but there are plenty flying that don’t have them. TCAS was definitely one of the acronyms I heard. There was a second one that I’ve forgotten that my instructor mentioned to me, as well. But he emphasized that your eyes were always your best friend when it came to looking out for other aircraft. ETA: Having now looked at Shagnasty’s link, I’m pretty sure it was TAS. ---
**Author:** ![GusNSpot](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gusnspot/32/436_2.png) [@GusNSpot](https://boards.straightdope.com/u/GusNSpot)\ **Post date:** [June 18, 2014, 5:50am UTC](https://boards.straightdope.com/t/helicopter-flight-paths/690946/24 "2014-06-18T05:50:40Z")
True Air Speed helps in collision avoidance? he he he I’m old, first thing I think of when someone says TAS. ---
**Author:** ![ElvisL1ves](https://avatars.discourse-cdn.com/v4/letter/e/5daacb/32.png) [@ElvisL1ves](https://boards.straightdope.com/u/ElvisL1ves)\ **Post date:** [June 18, 2014, 1:30pm UTC](https://boards.straightdope.com/t/helicopter-flight-paths/690946/25 "2014-06-18T13:30:20Z")
> [@Asimovian](#): > > TCAS was definitely one of the acronyms I heard. There was a second one that I’ve forgotten that my instructor mentioned to me, as well. Possibly [ADS-B](http://en.wikipedia.org/wiki/ADS-B). Still in the very early stages of implementation, and there will never come a time when everyone has Mode B transponders installed. [Previous page](https://boards.straightdope.com/t/helicopter-flight-paths/690946.md?page=1)