"just below glide path, begin descent"....for big planes this is the time to reduce thrust and start the process....

"Coming up, and on glide path"....for small planes this is the time to start.

"on course, on glide path"

"going left of course turn right 071"

"going above/below glide path"

"holding slightly above glide path"

"going well above glide path"

just examples of what you would hear on a typical day training students.

The glidepath for the PAR is usually 3 degrees unless otherwise noted. So, set the VSI appropriately and make corrections based upon the calls. If you have never done a PAR before, I really recommend doing a practice approach at your closest available field (rapidly becoming only Navy and Marine fields). They are usually kind of fun for guys that have never done them before. If you have a HUD, it takes all the work out of it. Set 3 degrees with the velocity vector and take a break.

For an ASR, you can either be given step down fixes or just told to descend to the MDA. Usually similar stepdowns to the Tacan approach. If they are using PAR to give you the azimuth for the ASR, they will often give you recommended altitudes every mile or so based upon a 3 degree glidepath. I use the 'dive and drive' method for ASRs though just like a Tacan.

And for those who really like a challenge, no gyro PAR/ASR. Actually its more of a challenge for the controller. I always make sure I do a no gyro version to give the controller the practice. Instead of headings to fly, they tell you "turn right/left" "stop turn" and you are expected to use half std rate turns. Obviosously simulating that your HSI is gone.

A guy up in Detroit APP got a controller award for doing one of these with a 182 that had lost his instruments. I forget the timeframe, but it was at least 15+ years since one had been done in that facility.

If there's no communication for 15 seconds during an ASR it's a miss, for a PAR, if you don't hear the controller every 5 seconds it's time to go around.

My question is that if other precision or non-precision approaches are avialable why would you fly an ASR approach?

The other approaches not being available is what you are simulating. Whether it would be due to aircraft or airport issues really doesn't matter.

You can drag a trailer out to the end of a runway and be doing PARs and ASRs in a couple hours. Setting up an ILS takes a while.

While shooting approaches for my currency, I've had controllers ask me if I'd like an ASR to maintain their currency. Happy to reciprocate and they are fun to fly - especially "no gyro".

If I have the gas, I'll almost always give our controllers a few approaches. I'd rather help them get better/stay current, then wait for a day I really need them to be on their game.