What is the benefit of a contact approach?
It allows you to avoid flying an entire approach.
>>>>>Aren't you generally vectored to the final app. course anyway?
Uhhh, nope, not always. you're porobably only likely to get a contact approach at a place that doesn't have terminal radar services anyway. Good luck getting cleared for a contact approach from approach control when the Wx is below VFR and they're sequencing traffic for instrument approaches. If Wx is above VFR, then a visual approach makes more sense anyway.
Does it allow more traffic into an area/reduce seperation?
No, like I said, you're only likely to be flying one at a place that doesn't have terminal RADAR services. In such a place, ATC can only let one airplane in and out of the terminal area at a time anyway. A contact approach will get you on the ground faster than flying the full approach, so in that sense it could increase traffic capacity into an airport.
A word of caution about contact approaches: Use them very carefully. Use them only at an airport where you are very familliar with the terrain, landmarks and obstructions. Essentially, a contact approach is a clearence to scud-run from your present position to the airport with the Wx below VFR minimums. Be absolutely sure you know that you will be able to pick your way to the airport, avoiding all the obstacles, in the existing conditions.
The following is a rant that has been building for a while. It's a little off the topic, but it was triggered by the comment:
"Aren't you generally vectored to the final app. course anyway?"
My comments aren't directed at Eric, nessecarily.
Folks, *know* your non-radar procedures. That's the fundamental on which the system is built. Yes, many of you fly in an environment where you are almost always vectored for final .... that's great, it makes things a lot simpler. But know what to do when you're not getting vectors, know when you're non-radar, and know why you're doing it.
Here's what happened when a couple of guys found themselves in a non radar environment:
http://www.ntsb.gov/NTSB/brief.asp?ev_id=20001208X07226&key=1
They died.
AOPA published an article on this accident in the last issue. It's obvious from the start that these guys didn't have a clue what to do without ATC telling them where to go. They wandered around aimlessly, they were confused about where they were, they couldn't read the approach plate and figure out the correct altitude, For god's sake, they went outbound on a procedure turn for 3 minutes, in a Lear, with the flaps up, with a tailwind, while descending almost 2000 feet (incorrectly) How far outside the protected area do you think they were when they finally turned back toward the airport? Never mind that they were already 1400 feet too low.
A few years ago, I was a passenger on an airplane (another Lear 35, coincidentally) on a black, rainy night going into a non radar airport in the middle of nowhere. Center told them "cleared for the approach, change to advisory approved" There was kind of an awkward pause, and the captain said to the FO, ummm, I guess we need to do a procedure turn, right? Then there was some discussion on how to do one ..... You can bet I was paying attention on that approach. They did fine once they got started, but the point is, when ATC tells you bye-bye, there shouldn't be any question in your mind what you're supposed to be doing next.
Don't get used to letting ATC fly the airplane for you. Know where you are. Know how to get to where you want to be without help. Know your non-radar procedures. The time to try to recall what your flight instructor told you about procedure turns is not right after ATC tells you to switch to advisory.
OK, I'm done ranting