ILS clearance question

[Prof. ATP]

Then if the GS is OTS does it not become a LOC approach? So if you are cleared for the ILS 18 and halfway through the GS craps out wouldn't it become a LOC approach?

IMHO, if the GS fails during the approach it becomes a missed approach. The techniques are different enough that I would not feel right to anything other than go back and do it right.

Also, there are a few locations with separate ILS and LOC charts, so reversion is not an option.

 

[Amish RakeFight]

The difference is that there are ILS approaches with ILS and LOC mins. and LOC only approaches. Whether the GS is OTS or not, you are still flying the ILS approach as charted, albeit without vertical guidance.

...and yeah, if you lose the GS during the descent, you should go missed as the LOC approach was not briefed. Things like minimums, visibilty and descent rate (VDP) change for instance.

 

[JCJ]

Because its not a localizer approach.

The approach is an ILS approach no matter what. If the GS is OTS, then the controller will still clear you for the ILS approach, but its the pilots responsibility to fly it localizer only.

Agree

And if the G/S is O/S it's the PIC's responsibility to know that and fly the approach to LOC only mins. It's a nice touch, though for ATC to remind the pilot that the GS is O/S when he gives the ILS clearance.

I think if you are on the ILS and lose the G/S, and your altitude is below LOC only mins, you must go missed.

If you are on the ILS and you lose the G/S above LOC minimums it is probably legal (Part 91) to level off at the LOC MDA and fly it to the MAP. As noted above, though it's probably safer to go missed and start over, unless a G/S failure - LOC approach was specifically briefed.

 

[down2mins]

FWIW - In that situation around here, I would typically hear "Cleared for the ILS 28L, Localizer only"

 

[circletoland]

The 7110.65 says "cleared ILS runway 36 approach, Glideslope unusable" in section 4-8-1 FYI.

 

[Mesabi Miner]

everything within 30 miles of the main bang.

I'll bet 75% of pilots don't know what the "main bang" is. Somebody took their ATC class!

MM

 

[CFII_4Ever]

I'll bet 75% of pilots don't know what the "main bang" is. Somebody took their ATC class!

MM

The spot on the plan where the radar antenna is at.

 

[Mesabi Miner]

The spot on the plan where the radar antenna is at.

Somebody took their ATC Class!

 

[afhercdriver]

Because its not a localizer approach.

The approach is an ILS approach no matter what. If the GS is OTS, then the controller will still clear you for the ILS approach, but its the pilots responsibility to fly it localizer only.

But if you deviate too low on the GS doesn't approach get an alarm? My point is if you use the dive and drive method to fly the LOC then you are going to be way below the GS. Right?

Jim

 

[Donsa320]

But if you deviate too low on the GS doesn't approach get an alarm? My point is if you use the dive and drive method to fly the LOC then you are going to be way below the GS. Right?

Jim

No, any alarms would be a "Low Altitude Alarm" which is generated based on obstacle clearance and rate of descent. The parameters in the facility should be set so that it will not alarm if the approach is flown as depicted. I suppose if you really pulled the power off rapidly at the FAF and came down like a stone to non-precision minimums you could probably could cause an alarm in the approach facility and they would call you to "Check Altitude". But that would be because of a rapid descent rate which causes the computer to look ahead and then go into alarm.
DC