IFR chart question
- Thread starter durind
- Start date
rframe
pǝʇɹǝʌuı
Good find MidlifeFlyer, I'll stand corrected.
It does make me wonder what the point of even having 91.175(k) is then.
This really reminds me of the Louis CK stand up on airline travel with aircraft maintenance...to modify and paraphrase...
"I'm sure the pilot is following some procedure manual that says, if you fly an ILS then use the marker beacon, if there's no marker beacon use DME, if there's no DME...well then F it!"
It does make me wonder what the point of even having 91.175(k) is then.
This really reminds me of the Louis CK stand up on airline travel with aircraft maintenance...to modify and paraphrase...
"I'm sure the pilot is following some procedure manual that says, if you fly an ILS then use the marker beacon, if there's no marker beacon use DME, if there's no DME...well then F it!"
Capt. Chaos
Well-Known Member
[quote="MidlifeFlyer, post: 2044043, member: 1194
That does not mean there will never be an ILS approach that requires DME. There could always be something special that needs to be done to tweak a particular approach. [/quote]
http://155.178.201.160/d-tpp/1301/06053ILDY11.PDF
vs
http://155.178.201.160/d-tpp/1301/06053ILDZ11.PDF
The ILS Y requires DME for the missed approach, on the ILS Z there is no DME note because of the required Radius Fix capability, but it does require ADF. Which although not explicitly noted on the ILS Y the ADF would still be needed for the missed approach as well.
That does not mean there will never be an ILS approach that requires DME. There could always be something special that needs to be done to tweak a particular approach. [/quote]
http://155.178.201.160/d-tpp/1301/06053ILDY11.PDF
vs
http://155.178.201.160/d-tpp/1301/06053ILDZ11.PDF
The ILS Y requires DME for the missed approach, on the ILS Z there is no DME note because of the required Radius Fix capability, but it does require ADF. Which although not explicitly noted on the ILS Y the ADF would still be needed for the missed approach as well.
rframe
pǝʇɹǝʌuı
Yeah, I think so far this discussion is limited to the final approach segment.
There are still plates with "DME Required" on the planview, in which case DME is required to transition from enroute and there are plates with "DME Required" in the Notes section of the briefing box, where DME is required to identify waypoints on the intermediate segment.
There are still plates with "DME Required" on the planview, in which case DME is required to transition from enroute and there are plates with "DME Required" in the Notes section of the briefing box, where DME is required to identify waypoints on the intermediate segment.
Ian_J
Hubschrauber Flieger
Are radius-to-fix paths required to be in the GPS data base or could I fly that arc just off of DME?
MidlifeFlyer
Well-Known Member
I think of it this way. A description or definition does not automatically create a pilot operating rules. Looking at 91.175(k), the only arguably operational rule I see is about what may substitute for the outer marker.
One other piece of food for thought in the discussion. I've always had a little difficulty with this one, so corrections are not only welcome, but wanted. You refered to this earlier, rfram e- There is a distinction to be made based on where a restriction or operating limitation appears on the approach chart. Continuing to use DME as an example, there are potentially 3 places where a requirement for DME will appear: the title of the procedure, the Plan View, and in the Notes. Again with corrections solicited, here's how I've come to understand it:
- Name of the Procedure (LOC/DME) - DME is required to fly the final approach segment. Using out PAE 34R approach as an example, DME is required for the LOC procedure in order to identify the FAF and the MAP. The "FAF" for the ILS is, as previously pointed out, intercepting the glideslope and the MAP is getting to the 763' DA and glideslope and not seeing what you need.
- On the Plan View (DME REQUIRED) - DME is required in order to enter the world of the approach from the en route environment. We don't have that note on our PAE ILS. You can get to either IAF without it.
- In the Notes (DME required) - DME is required in order to execute some part of the approach other than the final approach segment. We do have that in our PAE approach - "Simultaneous reception of I-PAE and PAE DME required." Without being TERPS guru, I'm guessing it's to identify WEBVE for the depicted HILO .
durind
Well-Known Member
This has truly been awesome to pick through these posts and gain some information from people who seem to have a far greater command of regulations and procedures than I could ever hope to have. Thank you all for the responses and information I truly appreciate it, time to tell my students I have been teaching them wrong. 
MidlifeFlyer
Well-Known Member
I don't know about anyone else but I don't keep all this stuff in my head (it would probably explode). So a great question like the one in this thread is a wonderful opportunity for a refresher.This has truly been awesome to pick through these posts and gain some information from people who seem to have a far greater command of regulations and procedures than I could ever hope to have. Thank you all for the responses and information I truly appreciate it, time to tell my students I have been teaching them wrong.
JetDrvr
Well-Known Member
gotWXdagain said:
That is not correct. The ILS antenna sends out glideslopes at 3°, 6°, 9°, and so on. You could be at the GS intercept altitude with the needles crossed while on the wrong glideslope. The only way to verify that you are on the correct GS is to have range information (DME, marker beacon, etc).
Also, as someone already noted, range is a required component of an ILS. What can be used to determine range is specified in the AIM, and it does not include GS intercept.
JetDrvr
Well-Known Member
MidlifeFlyer said:
Your definition of the FAF is not correct. From the PCG:
"FINAL APPROACH FIX- The fix from which the final approach (IFR) to an airport is executed and which identifies the beginning of the final approach segment. It is designated on Government charts by the Maltese Cross symbol for nonprecision approaches and the lightning bolt symbol for precision approaches; or when ATC directs a lower‐than‐published glideslope/path intercept altitude, it is the resultant actual point of the glideslope/path intercept."
As defined above, the FAF is depicted on the chart by the lightning bolt. Next to it is the crossing altitude on the GS. If you intercept the GS above or below the depicted altitude at the FAF, the only way to confirm that you're on the correct GS is to have range information (DME, OM, cross-radial, etc) to verify the crossing altitude crossing the FAF.
How would you get range information in this case?
gotWXdagain
Polished Member
True, you can get false glideslopes, so to clarify, proper airmanship dictates that one would intercept a glideslope from below. But by definition, final approach begins when descent is commenced.
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gotWXdagain
Polished Member
http://155.178.201.160/d-tpp/1301/05159ILD13.PDF
If DME was required for the ILS approach because the approach is named ILS or LOC/DME, then why is there a DME Required note in the planview?
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If DME was required for the ILS approach because the approach is named ILS or LOC/DME, then why is there a DME Required note in the planview?
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jeflies
Well-Known Member
Snippet from the AIM that I think applies here:
"When radar or other equipment is required for procedure entry from the en route environment, a note will be charted in the planview of the approach procedure chart (e.g., RADAR REQUIRED or ADF REQUIRED). When radar or other equipment is required on portions of the procedure outside the final approach segment, including the missed approach, a note will be charted in the notes box of the pilot briefing portion of the approach chart (e.g., RADAR REQUIRED or DME REQUIRED). "
In http://155.178.201.160/d-tpp/1301/05159ILD13.PDF the IAF/HILO has to be identified using DME.
The question I'd have is what if your getting radar vectors to final? This makes the IAF and HILO irrelevant.
Could it be for planning purposes only? ie. shooting this with lost comms so you'll need the DME to fly it full procedure
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gotWXdagain
Polished Member
Makes perfect sense then, that DME is only required on this approach because its the only reference you have to determine when to start the procedure turn/identify the IAF, however once the turn is completed, it becomes irrelevent for primary navigation.
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MidlifeFlyer
Well-Known Member
Yep. The point is that the location on the chart where the "[NAVAID] Required" appears tells you what phase of the approach it is required for. It may appear in multiple parts of the chart.
