ILS with NDB inop

[pstan]

Some discussion about this point. Let's say your destination has an ils approach with an ndb as the non precision FAF and GS check, the missed approach is to a VOR. The ndb is notamed out of service, you have no gps/rnav. ATC says they will provide vectors for the ils. Is it legal to fly the ils without an ndb/fan marker/cross radial/dme? The precision FAF is the glideslope intercept altitude, but if you fly the GS there will be no altimeter/glide slope cross check.
Thoughts anyone?

 

[RMCN172RG]

The short answer I was given is yes with vectors to final.

You can use the outer marker beacon to verify the GS reasonability test and if in doubt fly to the LOC minimums.

 

[poadeleted20]

As long as there's no note saying "ADF REQUIRED" anywhere on the chart, yes, it's fine as long as the GS is working both on the ground and in the plane.

 

[pstan]

thanks Ron, yes "ADF required" makes sense.

Ray, in my example there is no OM/beacon. Is this GS check and loc only minimums an FAR? AIM recommended procedure? or just a personal preference?

 

[Dr. O]

At my field we had an NDB on the approach chart for the ILS 27... They recently shut down the NDB to save money - and the RCO...,
(damn those GPS lovers - when the GPS system gets jammed or is INOP I will be right at the front of the crowd saying I told you so)...

denny-o

 

[poadeleted20]

Ray, in my example there is no OM/beacon. Is this GS check and loc only minimums an FAR? AIM recommended procedure? or just a personal preference?

There's no regulatory requirement for doing the GS/altitude crosscheck at the LOC FAF -- it's merely a good thing to do if you have the equipment. Obviously, however, if you lack the equipment to identify the LOC FAF, you can't do the check and you can't fly it as a LOC approach, so in that case, if you have doubts about the GS accuracy, continuing to LOC mins isn't permitted and a prompt climb to the missed approach altitude is warranted.

 

[azure]

As long as there's no note saying "ADF REQUIRED" anywhere on the chart, yes, it's fine as long as the GS is working both on the ground and in the plane.

Okay, this is something I've wondered about. The NDB component of the LOM at PHN has been OTS for about a year, and the skinny is they are not going to repair it. The ILS plate does say ADF REQUIRED. Are you saying that even with vectors, it's not legal to fly this approach under IFR? If that's true, they should notam the whole procedure as NA not just the NDB.

 

[poadeleted20]

Okay, this is something I've wondered about. The NDB component of the LOM at PHN has been OTS for about a year, and the skinny is they are not going to repair it. The ILS plate does say ADF REQUIRED. Are you saying that even with vectors, it's not legal to fly this approach under IFR? If that's true, they should notam the whole procedure as NA not just the NDB.

First, for those unfamiliar, here's the approach: http://204.108.4.16/d-tpp/1005/05445IL4.PDF

In this particular case, because the note is on the planform view, it means the ADF is required only for autonomous procedure entry, i.e., to go direct to PHURN to execute the PT. If you can get vectors to final, you can still fly the approach as either an ILS (using GS intercept for the FAF) or as a LOC (if you have a marker beacon receiver to get the OM as the FAF). And, of course, if you have an IFR GPS, you can still fly the full procedure as though you had the ADF/NDB both working, even though the underlying navaid (PHURN LOM) is inoperative.

 

[azure]

Okay... that's what I thought, thank you for the clarification. I'm still not clear though on why the note being in the plan view means it applies only to procedure entry. If it was meant to apply to the entire approach (i.e. approach NA without ADF), where would it be? In the title area? I seem to remember something about this in the AIM but it's been a while... I really need to brush up.

 

[poadeleted20]

I'm still not clear though on why the note being in the plan view means it applies only to procedure entry.

That's covered somewhere in TERPS.

If it was meant to apply to the entire approach (i.e. approach NA without ADF), where would it be?

In the Notes block, up with the A and T symbols, but even then, it's possible you could be cleared for the approach if they have an alternate missed approach instruction to give you. If there were no way at all to fly the approach without the other nav system, it would be in the title (e.g., VOR/DME RWY 5 vs VOR RWY 5).

 

[nosehair]

ATC says they will provide vectors for the ils. Is it legal to fly the ils without an ndb/fan marker/cross radial/dme? The precision FAF is the glideslope intercept altitude, but if you fly the GS there will be no altimeter/glide slope cross check.
Thoughts anyone?

Ask ATC to give you an "outer marker fix", or a specific mileage fix where you would expect to otherwise use the ndb as a GS/alt check.

 

[Arnold]

That's covered somewhere in TERPS.

AIM - 5-4-5 [see http://www.faa.gov/air_traffic/publications/atpubs/aim/Chap5/aim0504.html] - Scroll down.

3. The navigation equipment required to join and fly an instrument approach procedure is indicated by the title of the procedure and notes on the chart.

(a) Straight-in IAPs are identified by the navigational system providing the final approach guidance and the runway to which the approach is aligned (e.g., VOR RWY 13). Circling only approaches are identified by the navigational system providing final approach guidance and a letter (e.g., VOR A). More than one navigational system separated by a slash indicates that more than one type of equipment must be used to execute the final approach (e.g., VOR/DME RWY 31). More than one navigational system separated by the word “or” indicates either type of equipment may be used to execute the final approach (e.g., VOR or GPS RWY 15).

(b) In some cases, other types of navigation systems including radar may be required to execute other portions of the approach or to navigate to the IAF (e.g., an NDB procedure turn to an ILS, an NDB in the missed approach, or radar required to join the procedure or identify a fix). 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). Notes are not charted when VOR is required outside the final approach segment. Pilots should ensure that the aircraft is equipped with the required NAVAID(s) in order to execute the approach, including the missed approach.