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m4j2t

Active member
Joined
Aug 12, 2005
Posts
37
Here's a fun one...

you're IMC, on your way to airport abc where the weather is 300 and 3/4sm.

The glideslope is notam'd OTS.

The controller says "cleared for the ILS, glideslope unusable."

WHAT?!!

is this legal? and what does it mean?

again, reference material, not opinion
 
you are permitted to shoot the approach as if it were just a localizer approach. Use the published step down altitudes and MDA set forth in the LOC minimum (S-LOC RWY)
 
Front of the TERPS.

"ILS glide slope inoperative minimums are published on the instrument approach charts as localizer minimums"

AIM 1-1-9

Inoperative ILS Components

When the Glide Slope fails, the ILS reverts to a nonprecision localizer approach.
 
Last edited:
Sure it's legal. They're saying you're cleared for the localizer-only approach, but since the NAME of the approach is "ILS XX," ATC calls it that, adding that the GS is unusable. The name of the approach hasn't changed, only the way you fly it and the minimums.

It means you fly it as a non-precision localizer approach, doing step-downs at the appropriate points as depicted in the profile view. Separate approach minimums are published for this, under the heading "LOC," as opposed to the full ILS minimums.

A 300 foot ceiling may or may not allow you to see the runway in time, but 3/4-mile vis shouldn't be a problem. Take a look at the ILS 08L in ATL as an example. Full ILS mins are 1800 RVR, with a 200 foot DH. Localizer-only minimums are 2400 RVR, and a 425 (AGL) MDA.

Were this the approach you were doing, it'd be pefectly legal to shoot it. If it were a thick 300' overcast, you probably wouldn't see it at MDA, but you'd fine to try it as long as you have the required visibility (which you would).

Hope that helps.
 
m4j2t said:
.

The glideslope is notam'd OTS.

The controller says "cleared for the ILS, glideslope unusable."

m4,

Sounds like you had checked the NOTAMS...good show. Was there also an ATIS available supporting the info in the NOTAM ? NOTAMS aren't always current so an ATIS or question to approach about the GS status would be a good idea.

The big thing is not let them slam you into a non-precision approach when you were expecting/set up for a precision approach; they are two very different animals in the planning and execution. Scrambling to retool for the surprise is a setup for a mistake. You tell THEM what you're going to do.
 
I think this is what he was confused this, not what mins to use:

The controller says "cleared for the ILS, glideslope unusable."
CA1900 stated the reason, but I think it might of gotten lost.

Sure it's legal. They're saying you're cleared for the localizer-only approach, but since the NAME of the approach is "ILS XX," ATC calls it that, adding that the GS is unusable. The name of the approach hasn't changed, only the way you fly it and the minimums.
ATC can't just 'make up' approaches. They will clear you for the name of the approach that is on the approach plate, hence why the controller cleared you for the ILS. Because the GS was inop, they must remind you (per controllers handbook I believe) when they clear you for the approach that the component is inop. Hence, you'd do like everyone else said here and use the LOC mins.

Sorry if I just repeated everything ya'll said ealier.

~wheelsup
 
Sooooo... What did you do? Did you fly the approach? Did you set it up as the LOC?
 
aucfi said:
you are permitted to shoot the approach as if it were just a localizer approach. Use the published step down altitudes and MDA set forth in the LOC minimum (S-LOC RWY)
That's where having an FMS really shines...
Depending upon your magic box, you can often simply switch the approach to a localizer and soldier on using a psuedo-glideslope - without skipping a beat.

'Sled
 
I was teaching in Long Beach when this happened, and it came up a few times with students. As already stated:

The Title of the approach is the Long Beach ILS Rwy 30

ATC are telling you that the Glideslope is unusable.

Sometimes they will also have a Localizer only titled approach with different fixes, or procedures - perhaps if the tower is closed, no radar, no dme/ndb etc., or with a procedure turn of some sort.
 

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