Inbound Question
 

At what point are you considered "inbound", say after a procedure turn? When the course is "alive" or is it within one dot? And a reference would be great too.

Another scenario:
Let's say you are at 3,000' headed toward TAM from the south.
ATC says: Maintain 3,000' until established, cleared ILS 13.
At which point can you start your descent? After TAM? In PT?

http://www.tomzap.com/esc/APPROACHtampicoILS13.gif

Thanks in advance!

You're considered inbound when you're 137 course is centered on your LOC. "course alive" means that you can start your turn to follow your loc course to intercept the 137 inbound. This is basic IFR flying. If you're getting ready for an interview, you might want to hit up a CFII.

This looks like a XJET interview question. :D It's been so long since I've done one of these at XJET, so double check my answer.

Once you've reached TAM head outbound on the 317 radial. At 5.0 DME from TAM start your descent to 1400ft MSL and your outbound turn(45 to 60 secs outbound) then turn inbound & intercept the Rwy 13 localizer. Remember you're only protected from terrain/obstructions with in 15 DME of TAM or with in 10 DME of D5.0 TAM or D4.2 ITAM(Rwy 13 LOC).

Once established(needle centered) and crossing ITAM 4.2 you may follow the GS to 279ft MSL or you may descend to 440ft MSL if the GS is out if service.

You can also identify the GS intercept point with DME off TAM VOR(5.0 DME)

Check this info with the AIM. :p

That 1400' is only good if you are ON the radial or loc inbound within 10nm of TAM. Look at the MSA. If they told you to maintain 3,000, cleared for the approach, then stay there until at least you complete the procedure turn, the loc comes alive and you are within 10nm of TAM. Then you can descend to 1400. I know it's a short distance. If you go down to 1400 on your way out, then turn off the course to do the procedure turn, you may not know what you might run into.

Let me requalify my previous post. If you are within 15DME or 10DME TAM (same thing) then you can go down to 1400. Once the loc comes alive, and you are within the proper distance, you are terrain protected. I had to look at that plate again! Carry on.;)

Good read...

http://www.terps.com/ifrr/may96.pdf

Ten, ten and Clear.

Within 10 degrees of final approach course, 10 miles from VOR or whatever source the MSA is for and being cleared for the approach

if he's in instrument training...this is understandable...but if this is in prep for an interview....this is instrument 101 stuff

why no IAF labeled?

I'm here asking a question, not to be ridiculed about how I don't know instrument 101 stuff... thank you.

Are you certain established means you are "centered on the LOC?"

I have been flying a Hawker for the past 3 years. This isn't a scenario that you get everyday. When we practice in the sim, we use 1 dot to define "established" and that's when we can start our descent. Without going into too much detail in my original question, I was just trying to see if somebody can find the answer in writing somewhere.

BrewMaster: Good article.

The other part of my question refers to the time when you are able to start a descent after passing TAM. Is it after passing TAM outbound, or after the Procedure Turn and "established inbound"?

Is it a TERPS or PANS-OPS procedure? It would make a difference if coming from the south.

GF

I think you were correcting yourself, but just to clarify you can descend to 1400ft if you are established on the TAM 317 radial. Look at the profile. It shows a descent line to 1400ft with a 317 above the line. It also says 10NM of D5.0 TAM or D4.2 ITAM. Just stay with in 15 miles of the TAM VOR, as the 10 mi protection ring is centered around the TAM 5 DME point.

Yep, makes sense... 1,400' after TAM and "established" on the 317 radial.

Now my other question refers to "established." We have been training within 1 dot is established but I cannot find where this came from.

Within "1 Dot" comes from ICAO's definition of "on course"; or +\- 5 degrees for NDB. Check PANS-OPS Doc 8168, Vol 1. Technically, the FAA's position is that "on course" is needle centered, 1 dot off course and intercepting is technique to lead the intercept of the course, not "on course".

GF

GF -

While looking up some of the things discussed today with a fellow worker he pointed out to me the passage in the 'Instrument Procedures Handbook' which defined 'on course' as [1 dot]. I wrote down the reference manual and page number but don't have it with me now. That same paragraph also mentions the +/- 5 deg of oncourse bearing for the NDB as you mention above. Maybe this is another area where the FAA has adopted ICAO standards of recent?

USMCFLYR

Never flown into Mexico, but why is there no IAF labeled? In the U.S., could you even legally begin this approach without radar vectors?

The more recent version of the chart has a multitude of IAFs.

GF

I read in the Jeppesen instrument procedures guide that half-scale or less is established.

Thefly

Right out of ICAO Doc 8168, that is

GF

To the OP,

I think galaxy flyer's answers are best (though I haven't been based in the US in a few years.)

On another note, funny how some other posters were ridiculing you and it turns out that theirs were not the best answers. You'll find this a common theme throughout your career. Just keep asking questions and reading on your own to gain knowledge despite the detractors.

Amen!

Thanks for all the answers...

Although all approaches have an IAF, not all approaches have a charted IAF.

In this case, the IAF begins when on established on final from the PT or GS intercept.

Coffee Minutes

I don't think so. What you are describing is, in fact, the final segment. There are four approach segments--initial, intermediate, final and missed approach. The approach, non-radar, must begin at an IAF which must be depicted and is not on the OP's plates. The IAF and initial segment to to transition the aircraft from the enroute structure to the course reversal or intermediate segment. The lack of an IAF is a glaring error and the approach, under FAR 97, cannot be flown except in a radar environment.

GF

You are correct!

I was thinking about an uncharted FAF.

Ive been out of flying for 4 + yrs. and am trying to get refreshed by reading boards.